Department of Health and Human Servces

OFFICE OF

INSPECTOR GENERAL

NATIONAL DRG VALIDATION STUDY

UPDATE: TECHNICAL REPORT

AUGUST 199
 OFFCE OF INSPECfOR GENRA 
The mission of the Office of Inspector General (OIG), as mandated by Public Law 95
452, as amended, is to protect the integrity of the U.S. Department of Health and 
Human Servces (HHS) programs as well as the health and welfare of beneficiaries 
served by those programs. This statutory mission is carried out through a nationwide 
network of audits, investigations, and inspections conducted by three OIG operating 
components: Office of Audit Servces (OAS), Office of Investigations (01), and Offce 
of Evaluations and Inspections (OEI). The OIG also informs the Secretary of HHS 
program and management problems and recommends actions to correct them. 
OFFCE OF AUDIT SERVICE 
The OAS provides all auditing servces for HHS, either with its own resources or by 
overseeing work done by others. Audits examine the performance of HHS programs 
and/or its grantees and contractors in carrng out their respective responsibilties. 
Audits provide independent assessments of HHS programs and operations in order to 
reduce waste, abuse, and mismanagement; and to promote economy and effciency 
throughout the Department. 
OFFCE OF INTIGATIONS 
The 01 conducts criminal, civil, and administrative investigations of alleged 
wrongdoing in HHS programs or to HHS beneficiaries, and of unjust enrichment by 
providers. The investigative efforts of 01 lead to criminal convictions, administrative 
sanctions, or civil money penalties. The 01 also oversees State Medicaid fraud control 
units which investigate and prosecute fraud and patient abuse in the Medicaid 
program. 
AN 
OFFCE OF EVALUATION  INSPECfONS 
The OEI conducts short-term management and program evaluations (called 
inspections) that focus on issues of concern to the Department, Congress, and public. 
The findings and recommendations contained in these inspection reports generate 
rapid, accurate, and up-to-date information on the efficiency, vulnerabilty, and 
effectiveness of departmental programs. 
BOTEC Analysis Corporation prepared this report under the direction of Janet 
Wilson Knight. Contract information and project participants appear in appendices 
and 2.  Department of Health and Human Servces

OFFICE OF

INSPECTOR GENERAL

NATIONAL DRG VALIDATION STUDY

UPDATE: TECHNICAL REPORT

AUGUST 199 OEI-12-89-191
 EXECUTIVE 
SUMMAR 

PUROSE 
This inspection reabstracted the International Classification of Diseases, 9th Edition
Clinical Modification (lCD- CM) codes from a sample of Medicare 
discharges on a
blinded basis. It compared the resulting diagnosis-related group (DRG) 
to the 
hospital's DRG to determine 
over-reimbursement or under-reimbursement. . The
sample was nationally representative and covered all of calendar year 1988
, the most
recent data available. 
This study updates a previous inspection from the Offce 
of Inspector General (OIG).
It found that 20.8 percent of 1985 Part A bils contained coding errors that 
changed
the DRG and that 61.7 percent of these errors over-reimbursed the 
hospitals. This
improper DRG "creep" increased total prospective-payment system (PPS)
disbursements by 1.9 percent or $308 milion. 
FIINGS 
DRG coding error reduced
: 14.7 percent of 1988 discharges had DRG coding errors.
This proportion of coding errors was 
statistically significantly lower than the 20.
percent reported for 
1985. 
DRG creep eliminated: 51 percent of DRG errors over-reimbursed the hospital and
49 percent under-reimbursed the hospital. 
DRG coding errors. overall. no longer over-reimburse hospitals: Taken together, 1988
DRG errors had the net financial effect of under-reimbursing all hospitals a 
statistically non-significant $69.8 milion
, or 0.1 percent of the $52 bilion in 1988 PPS 
disbursements. Projected nationally" over-reimbursements totaled $2 657.8 milion and 
under-reimbursements totaled $2 588.0 bilion. 
Mis-specification errors under-reimbursed the hospitals
: Of the 361 DRG errors in the 
sample, 63.2 percent occurred because the attending physician 
mis-specified the
narrative diagnoses. Of these 227 
mis-specification errors, only 43.
2 percent over-
reimbursed the hospitals. The statutorily-required 
attestation probably reminded
physicians of their obligation to select accurate narrative 
diagnoses. 
Resequencing errors over-reimbursed the hospitall
: Of the 361 DRG errors in the 
sample, another 26.6 percent occurred because the hospital substituted a 
secondary 
diagnosis for the (correct, narrative) principal diagnosis. Of these 96 resequencing 
errors, 66.7 percent over-reimbursed the hospitals. The sentinel effect of the Peer 
Review Organizations surveilance apparently did not fully prevent over-
reimbursement due to resequencing.  REMMATIONS 
The Peer Revew Organtions should contiue their sureilance of hospita
cog 
for DRG reimbmsement accmacy. 
The attestation requirement appears to have deterred 
over-reimbursement due to 
mis-'specifcation by attendig physicians, causing their hospitals to be under-
reimbursed. However, the sentinel effect did not fully prevent over-reimbursement 
due to resequencing by hospitals. Although these two trends approxiately 
offset
each other, this equilbrium may not continue in the future. 
The Agency for Health Care Policy Research plans to reabstract the ICD-
codes from a large sample of Medicare charts to determe 
their diagnostic
accuracy for health servces research purposes. Using 
1991 data, grouping these
ICD- CM codes to DRGs, and selecting reasons for any diferences would provide 
a third time point with which to track trends in reimbursement 
accuracy. The OIG
supports this effort. 
COMM 
AGENCY 
In its May 29, 1992 comments to the draft of this inspection, the Health Care
Financing Agency (HCFA) concurred with the OIG recommendation. 
The HCFA
noted that the improvement in DRG coding accuracy may be attributable to increased 
hospital experience with PPS, PRO review, and HCF A educational efforts. 
The HCF A also made a number of technical 
comments. Based on these comments 
the OIG made several 
changes to this report. The full text of the HCF A comments 
appear as an appendix.  ...........................................................  . 
..  ...   ....    .....     ......      ......      ......      .......      .......     . ...... .     .. .......     .   ........  .      ........  ..      .. ......  ..      .. .......  .      .. .......   .     ... .... .     .   ....... ..      .  ........ .       . ........ .       . ........ .       . .........        . .........       .  .........  .       ......... .        ..........         ..........         ...........          .............        . . .......... .         .    .............. .             . ..............    .      .  ....... ...... . .. ......   . ...   . .....        
..  ..  ..  ..  ..  ..  ..  ..  ..  .....     ......      ......      ......      "...-...       .......       .......       .......       .......       .......       .......       ...... .    .  .... . .   . . ... . .   ..  ...  ..   .. .. .  .   ... ...   .   ..... .     . ......       .......       .......       .......       .......       .......       ........        ........        ........        ........       . ...... .      .. .... .    . . .... .     .. .....  .     . ......  .     .. ..... .      . ...... .       .....     ....    ....    .... .... .   
TABLE OF CONTENTS

EXECUTIVE SUMMAY. . . 
iii 
TABLE OF CONTENTS 
INODUCfION 
TH 
ORIGIN OF  PRESENT STUY 
1983-1988 GROUPER CHAGES

PAYMNT ISSUES

METHODOLOGY

SAMPLE DESIGN. . . . . 
DATA COLLECTION 
DRG REABSTRCTION 
.............................. 6 
ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
REPRESENTATIVNES 
.................................. 9

FININGS. . 
DRG CODING ERROR REDUCED 
EQUAL NUMBERS OF DRG ERRORS OVER-REIMBURSE AND 
UNDER-REIMURSE. . 
DRG CREEP ELIMINATED 
DRG OVER-REIMURSEMENT ELIMINATED 
MIS-SPECIFICATION UNDER-REIMBURSES, WHILE 
RESEQUENCING OVER-REIMURSES 
CERTAI DRGS ARE MORE SUSCEPTIBLE TO ERROR. . . 
RECOMMNDATIONS 
ENDNOTES 
.
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . noitamrofnjtcartnoCA pp:en1dix 
Appendix 2: Project participants 
Appendix 3: Calculation formulas 
Appendix 4: Representativeness of selected discharges, 1988 
Appendix 5: Nonresponses
, 1988 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Appendix 6: Proportion of DRG coding errors by hospital demography, 1988. 
Appendix 7: Proportion of DRG coding errors by patient demography, 1988  ............... ............................ ......
.. ... .. ...  . ... ..
. . ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ...   ...   ...   ...   ...   ...   ...
. . . . . . . . . . . . . . . . . . ..  ..  ..  ..  ..  ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  .. .  ..  .. . .  ...
Appendix 8: Interaction potential by hospital and patient demography, 1988 .

Appendix 9: Projected national CMI before recoding by hospital demography, 
1988 
Appendix 10: Projected national CMI before recoding by patient demography, 
1988 . . . . . . . . . . . . . . . . . . .

Appendix 11: Projected national CMI after recoding by hospital demography, 
1988 ... 

Appendix 12: Projected national CMI after recoding by patient demography, 
1988 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Appendix 13: Mean CMI change by hospital demography, 1988 . . . . . . . . . . .

Appendix 14: Mean CMI change by patient demography, 1988 ...........

Appendix 15: Mean reimbursement change by hospital demography, 
1988 ...

Appendix 16: Mean reimbursement change by patient demography, 1988 . . . .

Appendix 17: Number of bils by hospital 
demography, 1988 

Appendix 18: Number of bils by patient demography, 1988 . . . . . . . . . . . . . .

Appendix 19: Projected reimbursement effect by hospital demography, 1988 .

Appendix 20: Projected reimbursement effect by patient demography, 1988 . .

Appendix 21: DRG frequency, error frequency, and error proportion by

proportion of errors
, 1988 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Appendix 22: Mean weight, dollar change, and estimated national financial

effect by DRG, 1988 . . . . . . . . . . .

Appendix 23: HCFA comments. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . .  INTRODUCTION

Since the inception of the Medicare program, health care expenditures have grown 
faster than the rest of the economy, and the Medicare program has grown even faster 
than general health care expenditures. The need for innovative reimbursement 
policies and their evaluation has become critical to medical communities, beneficiaries 
and payers of the Medicare program. 
ORIGIN OF TH PREENT STUY 
Since 1965, Medicare has provided hospital and medical insurance to the nation 
elderly and disabled.  However, rapidly escalating health care costs coupled with a 
rise in the proportion of the population eligible for Medicare have burdened its 
hospital insurance trust fund (Part A). Health care costs accounted for 7.4 percent of 
the gross national product in 1970, 9.1 percent in 1980, and 10.9 percent in 1986. In 
1970, Medicare paid 8 percent of all health care costs, but by 1986 Medicare 
proportion increased to 17 percent.

In 1983 Congress changed Medicare inpatient reimbursement from a retrospective 
reasonable-cost basis to a prospective-payment system (PPS).3 Under the PPS 
hospital payments depended upon the patient's diseases and procedures as defined by 
the International Classification of Diseases, 9th Edition, Clinical Modification (ICD
CM).4 The PPS "grouped" various combinations of the approxiatelllO OOO ICD
CM codes into 470 (currently 476) diagnosis-related groups (DRGs). By reimbursing
the average cost of care for each DRG, the PPS provided incentives for efficient 
/ delivery of health care. The Veterans Administration Medical System Resource 
. Allocation Method emulated this change. 
A hospital fies a claim for Medicare payment at the time of patient discharge. The
attending physician writes the narrative diagnoses and procedures on the face sheet; 
and attests to the principal diagnosis, secondary diagnoses, and any procedures. The 
hospital' s medical records department then assigns numeric, ICD- CM codes to the 
narrative diagnoses and procedures, using the rules of the Uniform Hospital Discharge 
Data Set (UHDDS), "a minimum data set used by HHS programs to collect data on 
"6 The 
individual hospital discharges on a continuing basis. hospital's billng 
department enters up to five diagnoses and three procedure codes on the Medicare 
claim form. A 
Fiscal Intermediary (FI) receives the hospital bils for each State. 
runs GROUPER software to select the correct DRG by assessing diagnosis and 
procedure codes. It then runs PRICER software that adjusts for geographic location 
teaching costs, and other factors to calculate the payment due to the hospital. 
Since 1976 the Office of the Inspector General (OIG) has had responsibilty for

protecting the integrity of the programs and program beneficiaries of the U.

Department of Health and Human Servces (HHS).7 Following this statutory

mandate, the OIG commissioned the 1985 National DRG Validation Study (1985

Study), which examined how the processes that assigned 
diagnosis and prQcedure
 codes affected the accuracy of PPS reimbursement for Medicare discharges.s The 
1985 Study analyzed a representative, national sample of medical records to obtain 
information on the accuracy of the diagnosis and procedure coding, the impact of 
coding errors on DRG assignment, and the potential net financial impact of coding
errors. It also assessed the appropriateness and quality of the servces provided to 
Medicare patients. 
The 1985 Study found an overall error proportion of 20.8 percent in assigning DRGs. 
In 61.7 percent of the errors, the hospitals over-reimbursed themselves. Physicians 
mis-specification of narrative diagnoses and hospital biling departments' resequencing 
of diagnoses caused most errors. These errors caused $308 milion in overpayments to 
hospitals, 1.9 percent of 1985 PPS reimbursement. 
The Health Care Financing Administration (HCF A), as the payer of the Medicare 
reimbursements, made the following points in commenting on the 1985 Study. 
The PPS started in 1983. The 1985 Study data covered FY 1985. Physicians 
hospital coders, and Peer Review Organizations (PROs) needed a longer learning 
period to adjust to the new payment and quality monitoring system. 
The 1985 Study appeared in 1987, so that its conclusions derived in part from 
information and coding conventions that had undergone updating by that time. 
The HCF A and hospital associations recently had begun to conduct training 
seminars for hospital personnel. The HCF A therefore expected that coding errors 
would decrease over time. 
To examine these trends, the OIG initiated this follow-up project, implemented 
through contracts with the Health Data Institute (HDI) of Lexington, Massachusetts; 
American Medical Records Association (AMRA) of Chicago, Ilinois; and BOTEC 
Analysis Corporation (BOTEC) of Cambridge
, Massachusetts using 1988 data. This 
DRG Validation Study Update (1988 Study) had the purpose of determining how the 
PPS' s coding accuracy changed over time. The OIG designed this inspection to meet
the followig objectives. 
Replicate the 1985 work on coding accuracy, using 1988 data. 
Compare the findings from 
1985 and 1988. 
Identify patterns of coding errors that PPS changes 
could modify. 
As in the previous study, this inspection assessed how coding errors affected hospital 
reimbursement and identified the coding problems most subject to error. It evaluated 
hospital and beneficiary characteristics for their relative contribution to DRG errors.  198-1988 GROUPER CHGES 
The HCF A annually updates the taxonomy by which the ICD- CM codes group to 
DRGs.lO 11 1213 14 15 16 17 It seeks to improve the GROUPER' s fairness 
without a negative effect on patient quality of 
care. The adjustments respond to 
comments and suggestions from providers and administrators who work with the PPS 
in the field. The HCFAadopted the following major changes to the GROUPER from 
1985 to 1989.

DRG 471 (majQLnt procedures): In FY 1986, the HCFA created DRG 471 to 
include bilateral multiple major joint procedures. 
DRG 433-438 (alcohol and drug a  : In FY 1986, the HCF A completely 
reclassified these DRGs and dropped DRG 438. The exclusion of drug and alcohol 
treatment facilties from the PPS ended as of FY 
1988 (October 1, 1987). 
HIV codes: In FY 1986, the HCFA incorporated the newly created ICD- CM codes 
for HIV. This disease formerly fell into ICD- CM diagnosis code 279. 
19 (other 
deficiency of cell-mediated immunity) which grouped to DRGs 398 
and 399 (immunity 
, AIS 
disorders).  Mter  1986 grouped to infectious disease DRGs. 
DRG 385 (newborn transfers): In FY 1987, the HCFA reclassified DRG 385

(neonates, died or transferred) so that it applied only to transfers to another acute

care facilty.

DRG 472 (burns): In FY 1987, the HCFA changed DRG 457 to "extensive burns 
. without an operating room procedure" and created DRG 472 for "extensive burns with 
operating room procedures. 
DRG 473 (leukemia): In FY 1987, the HCFA removed acute leukemia cases in 
patients over age 17 from DRGs 401-405 and placed them in the new DRG 473. 
Age over 69: In FY 1988, the HCF A eliminated "age over 69" as a criterion in all of 
the DRG pairs in which "age over 69" and/or complication-comorbidity (CC) was a 
factor. The HCFA continues to use "age under 18" in certain pediatric DRGs and to 
use " 35" in DRG 294 (diabetes) and "age 0-35" in DRG 295 (diabetes). 
age 
DRG 103 (heart transplant): This DRG did not have a relative weight assigned until
FY 1988. 
DRG 474 and DRG 475 (ventilators): In FY 1988, the HCFA created DRG 474 
(respiratory system diagnosis with tracheostomy) and DRG 475 (respiratory system 
diagnosis with ventilator support) to separate the resource intensive ventilator cases 
from other respiratory DRGs.  Complication-comorbidity exclusions: In FY 1988, the HCF A implemented the 
exclusion list for complications and/or comorbidity, which is based on the principal 
diagnosis. The HCFA has made changes to this list each year. 
DRG 468 (unrelated operat ng room procedures): Each year, the HCFA has further 
refined this DRG by assigning more of its procedure codes to other specific DRGs. 
- FY 1989, two new DRGs were created in order to split DRG 468 even further: DRG 
476 (prostatic operating room procedure unrelated to principle 
diagnosis) and DRG
477 (non-extensive operating room procedure unrelated to principle 
diagnosis). 
Surgical hierarchies: Every year, the HCF A examines the surgical hierarchies for the 
GROUPER computer software logic and makes numerous changes. 
Each year, the relative weights change to reflect alterations in resource consumption 
coding, surgical hierarchy, and further DRG refinements. The HCFA presently tends
to expand the DRG list with more specificity in each DRG. This taxonomic splitting
allows the providers and hospitals to account for resource utilzation more 
accurately 
rather than averaging high and low utilzation conditions in the same DRG, but at the
cost of greater reimbursement complexity. The OIG has a more detailed 
description
of GROUPER changes that it will supply upon request. 
PAYMNT ISUE

The 1985 Study alludes to two probable sources of DRG coding error: random human 
error and systematic bias inherent to the coding system. First, error occurs naturally
./ in every human endeavor. Presumably, over the PPS's five years of operation, general 
. knowledge of the coding process increases and the overall error rate decreases. 
Whether due to time pressure or want of education
, any human coding errors should 
occur stochastically, not favoring either the hospitals or Medicare. However
1S 19 "  , the 1985 
Study finds intentional "gaming" or manipulating the coding process, not random
variabilty.
Second, the DRG coding system may have inherent contradictions that make 
errors 
and inaccuracies inevitable. Certain DRGs or their 
underlying ICD- CM codes have 
high frequencies of coding error. For example, DRG 99 (respiratory signs and
symptoms) has a high error rate because of it lacks a definite 
diagnosis and represents 
a cluster of symptoms. The DRG system may "build in" this tye of variation. 
In addition, some commentators propose modifyng the PPS to adjust for severity of 
20 This modification measurement would increase the precision with 
ilness.
which 
relative weights model actual resource consumption. However, unpublished data
submitted to the HCF A indicates that severity reduces DRG variance by only one-
third. In addition, collecting sufficient clinical data to quantify severity imposes 
significant transaction costs.  The PPS could also systematically overpay or underpay certain classes 
of hospitals. 
The most complicated and resource-intensive procedures, such as organ transplants 
are rarely scheduled in small, nonmetropolitan hospitals. They therefore have no 
opportunity for the substantial reimbursement (or under-reimbursement) that 
accompanies such servces. Conversely, medium-sized hospitals may attempt such

procedures but with relative inefficiency compared to the higher volume at large

metropolitan, teaching hospitals.

MEODOLOY 
The 1988 National DRG Validation Study Update used essentially the same methods 
as its predecessor study. 
SAPLE DESIGN

The initial study population consisted of the 10.8 milion Medicare funded discharges 
for calendar year 1988 from the 6 715 acute care, short-stay hospitals in the United 
21 The design then excluded 
States. discharges from specialty institutions such as 
children s hospitals, tuberculosis units, and psychiatric facilties. It also excluded 
discharges in Maryland and New Jersey, which were stil exempt from the PPS in 1988. 
It covered final bils only, omitting interim bils. It excluded bils for pediatric 
obstetric, and psychiatric DRGs (principally drug and alcohol rehabiltation performed 
by a general hospital). Unlike its fiscal year (FY) 1985 predecessor, it included 
hospitals established since the advent of PPS in 
1983. 
/ The HCF A required two quarters following the close of a year to accumulate bils 
paid by its fiscal intermediaries and combine the reimbursement data into computer 
files. This administrative data consolidation imposed a continuous lag on the 
availability of information defining the study population. Accordingly, billing data for 
CY 1988 became available in the middle of 
1989. 
The 1988 National DRG Validation Study Update used a two-step, non-clustered 
sampling procedure. The first step selected all bils whose Health Insurance Claim 
(HIC) numbers terminated in 95, a one percent, simple, random sample (SRS) of all 
. Medicare biling records for calendar year (CY) 1988. The OIG screened out interim 
bils, exempt States, non-acute care hospitals, and nongeriatric DRGs as described 
above (n=88 455). Starting from a random seed, the second step systematically 
sampled lout of every 33 of the biling records selected in the first step for a final 
sample size of 2 680. This process resulted in a self-weighting SRS. Oversimplified 
each sample biling record represented 3 300 biling records in the total population of 
biling records.

These discharges came from 1 744 hospitals, 26.0 percent of the acute care, short-stay
hospitals that accept Medicare patients. The hospitals represented 47 of the 54 States 
or other jurisdictions (District of Columbia, Puerto Rico, Guam, Virgin Islands) that
the HCF A recognizes. Since there was no stratification or 
clustering, most hospitals  .. 
contributed only one discharge to the sample. No hospital contributed more than nine 
discharges. 
DATA COLLCTON 
The OIG ran SAS on the HCF A's mainframe ffM 3090 to sort the sample by HCF A 
hospital identification numbers and match-merge the sample with the HCF A fie of 
provider addresses. It then used WordPerfect software running on a Zenith Z-
248 
personal computer to produce mailng labels and "personalized" letters from the 
resulting address fie. Each letter requested that the hospital's medical records 
department send complete copies of the sampled medical records to the OIG' 
contractor, HDI. Each mailng included a franked, addressed envelope and promised 
to reimburse the hospitallOC: per page for its copying costs. The OIG made 
additional mailngs and the HDI made follow up telephone calls to those medical 
records departments which did not provide the requested records. Although 
phrased 
as a request, all contacts communicated that hospital participation was mandatory. 
The majority of hospitals promptly supplied the requested medical records. Four 
hospitals declined to participate as requested, so the OIG issued subpoenas compellng 
their cooperation. Medical records departments could not provide 229 sampled 
records principally because they were missing, destroyed, or otherwse physically
unavailable. 
The OIG contracted (HHS-100-86-0054) with the HDI to log-in and secure the 
arrving medical records. The HDI matched medical records to the sample biling 
/ records, checked medical records for completeness and legibilty, inserted each 
. medical record in an individually labeled folder, and counted the pages to be
reimbursed. It also followed up incomplete medical records and handled similar 
administrative obstacles. 
Unfortunately, a change in ownership and reorganization of Baxer, the parent
company of the HDI, delayed some payments to hospitals. Although both the HDI 
and this contract apparently garnered profits for the parent, Baxer elected to disband 
the HDI for insuffcient profitabilty. The HDI ceased operations prior to completing
its contracted tasks, compellng the government to terminate the HDI contract for 
default. 
RESTRCTON 
DRG 
The HDI transmitted the accumulated records to the AMRA. The OIG separately
AM 
contracted (HHS-100-89-0022) with the  to reabstract the ICD- CM codes 
supported by the medical record, select the principal diagnosis, and group to select the
DRG. To ensure that the original ICD- CM codes and DRGs did not affect the 
AMRA' s reabstraction, the AMRA coders conducted this reabstraction without

knowledge of the original ICD- CM codes and DRGs. The AMRA 
also identified
 the reasons why a hospital's bil differed from the correct codes. Finally, it entered its
reabstracted codes into a personal computer database provided by the OIG. 
As the credentialing body for medical records practitioners the AMRA had expert 
knowledge of coding intricacies and access to nationally recognized RRA (Registered
Records Administrators) and ARTs (Accredited Records Technicians) who were
experienced ICD- CM coders. Unlike most other organiztions that employed expert
coders, the AMRA was (and is) independent of the hospital industry. The
used the offcial HCFA GROUPER softare (3M's Codefinder) to determine the
AM 
DRG for each reabstracted record. The 
compared the DRGs that Codefinder 
produced from the reabstracted ICD- CM codes with the DRGs supplied by 
providers and noted the results of these comparisons in the database. 
An RRA who was a nationally recognized expert in ICD- CM coding and who had
not participated in the initial reabstraction reviewed all records where the AMRA 
DRG differed from the provider DRG. The AMRA then 
grouped the revised codes
and made the appropriate changes in the database. The OIG also contracted with a 
physician with current knowledge of coding and 
cliical issues (SA-90-0633) to identify 
the principal diagnosis, secondary diagnosis, and appropriate procedures in cases 
where the resultant DRG differed from the provider s DRG (whether the same as the
initial AMRA coder or different from both the initial AMRA coder and provider). 
An RRA who had not been involved in the initial reabstraction and coding or the 
expert review compared all records reviewed by the physician to the provider 
s data
. and the AM' 
s data. Where the physician had agreed with the AMRA the 
/ did not change the database. Where the physician had agreed with the provider and 
AM 
. provided additional information overlooked by the  or provided special insight 
with which the third RRA agreed, the AMRA changed the database to reflect the 
codes of the DRG of the provider. Where the third reviewer was not convinced that 
there should be a change from the AM' 
s coding and DRG assignment, the OIG
medical officer reviewed the case arid made a final determination. The 
entered this determination as the final code and DRG determination. 
The AMRA also classified every coding error as mis-specification, miscoding,

resequencing, or "other." The AMRA entered its coding 
selections into a series of

database files. Its small personal computers could not hold all its coding output at

AM 
once. Computer experts from the OEI's office in Region V helped the 
set up
and maintain the databases. Upon completion of the AMRA reabstraction and data 
entry, the OIG-OEI-Region V office off-
loaded the fies for transmission 
headquarters. 
ANALYSIS 
The OIG contracted with BOTEC (HHS-100-90-0023) to analyze the results of

AMRA' s reabstraction of ICD- CM codes and DRGs. BOTEC has extensive

experience in the statistical analysis of reabstracted data. It has conducted such
 analyses for OIG on several previous occasions (HHS-100-89-0019, HHS-100-88-0019 
HHS-100-88-0624). BOTEC's work in this area has included the processing of medical 
records, the construction of r abstraction databases, the statistical analysis of 
reabstraction data, and policy analysis. 
The OIG provided BOTEC with a SAS data set containing merged biling records and 
AM 
the  reabstraction data. The OIG also provided BOTEC with a spreadsheet 
fie containing DRG weights for all DRGs for the years 1985 through 1989. Finally, 
the AMRA provided BOTEC with an updated set of reabstraction data and billng 
record data that contained additional information. 
BOTEC match-merged these three data sets into one comprehensive SAS data set. 
At this point BOTEC constructed simple frequency distributions of all variables and 
cross-tabulations of certain pairs of variables to examine the data set for incorrect or 
inappropriate codes and/or logical inconsistencies. All such ambiguities were resolved 
or corrected in consultation with the OIG. 
BOTEC then used SAS to create several additional variables that the current analysis 
required. These variables include exact age of patient at the time of admission 
change in DRG weight as a result of reabstraction, location of provider (metropolitan 
if in an Standard Metropolitan Area, nonmetropolitan if not), teaching status of 
provider (teaching if the hospital had any interns, nonteaching otherwse), controllng 
agency of provider, and bed size of provider (small if 1-99 beds, medium if 100-299 
beds, and large if 300 or more beds). Throughout this process BOTEC kept electronic 
and printed copies of the programs used to create intermediate data sets 
/ documentation of these data sets, and the data sets themselves. 
BOTEC began its analysis of the 1988 calendar year data by ensuring that the sample 
accurately represented the population from which it was drawn with respect to both 
provider and patient demographics. It compared the distribution of biling records in 
the 1988 sample with the population of biling records from which it was drawn using 
the variables provider size, location, control, and teaching status and patient age, sex, 
and race. BOTEC  statistic to reject the null hypothesis that the distributions 
used a 
were different. 
Hospitals were unable to provide medical records for 229 billng records in the 
original 
sample. This 8.5 percent nonresponse rate could have introduced systematic bias into 
the sample. BOTEC therefore repeated the tests for representativeness to determine 
whether there were differences in the distributions of responses and nonresponses. It 
also retested for representativeness using the same procedures as before, but with 
nonresponses removed. This slightly smaller sample stil accurately represented the 
general population. 
BOTEC then conducted "breakdown" analyses for a series of dependent variables. 
the first analysis it constructed a cross-
tabulation table by cross-tabulating the four 
provider demographic categories. The resulting table contained 144 cells. For each  cell BOTEC calculated and displayed for a given dependent variable that variable 
mean, standard error, and the number of cases in the cell. 
In the second "breakdown" analysis BOTEC constructed a cross-tabulation table by 
cross-tabulating the three patient demographic categories. The resulting table 
contained 75 cells. Again, for each cell BOTEC calculated and displayed the 
dependent variable s mean, standard error, and number of cases. By examiing the 
eight resulting tables for confdence intervals which had little or no overlap, BOTEC
determined which provider and patient demographics has a significant impact on these 
dependent variables. 
BOTEC conducted three additional 
analyses on the 1988 data. The first estimated the 
total financial impact of DRG errors by hospital and patient 
demographics. The
second analysis examined DRGs to determine which DRGs seemed to 
present the
most coding difficulty. The third analysis estimated the financial impact of DRG 
errors by DRG. 
To estimate the total financial impact of DRG miscoding by demographic categories
BOTEC multiplied the mean change in case 
mix index by Medicare standardized
amount in 1988 for each cell in the analysis tables. This was an estimate of the mean 
change per bil in each cell. BOTEC then multiplied this by the number of bils in
each cell to get an estimate of the overall financial impact of DRG errors 
within each
cell. They 
also calculated standard errors of these estimates. 
To estimate which DRGs represented the most 
coding dificulty BOTEC organied
/ DRGs in the 1988 sample by several different criteria: by frequency of occurrence in 
. the sample, by errors in DRG group, and by relative weight change. 
To estimate the financial impact of DRG 
miscoding by DRG, BOTEC multiplied the
mean change in case mix index by Medicare standardized amount in 
1988 for each 
observation in the sample and by the weight which each observation represents in the
population from which the sample was drawn. The mean by DRG was then 
calculated to give an estimate of the overall financial impact of 
DRG errors for each 
DRG. BOTEC also calculated standard errors of these estimates. A fuller 
description
of the calculation formulas appears in Appendix 3. 
REPREENATI 
The final sample of 2 451 medical records accurately represented the characteristics of 
the underlying population. Distributed by 
hospital demography, it did not differ from
the population in bed size, teaching status, location, or control. (Table 1). 
The sample also accurately represented the underlying population by patient 
age and
sex. However, the OIG made remedial 
efforts to classify unknowns by race. This
match to other government files reduced the proportion of sample 
unknowns in 
comparison to the underlying population.22 The volume of cases precluded a similar  reclassification of unknowns for 
Hospital  Medicare  Responses 
the entire population. Without the 
demography  n (%)  n (%) 
OIG' s reclassification, the sample 
would also have conformed to  99 beds 1 
333 250 (14.  359 (14. 
racial distribution of the underlying  299 beds 3 
100- 454 578 (36.  893 (36.4) 
population.  300+ beds 4
718 527 (49.  199 (48.9) 
Chi-square 0.  , 2 df P=0.626. 
Comparing the 2 680 "selected" 
Teachig 4
discharges with the population of

076 175 (42.9) 1 008 (41.1)

all CY 1988 Medicare discharges  Non-teaching 5,430 180 (57. 1) 1 443 (58.

(mius the exclusions for specialty 
Chi-square 3.  , 1 df, P=0.080.

institutions, exempt States, and 
specialty DRGs) revealed no  Profit 1
022 922 (10.  272 (11.1)

significant diferences in hospital  Nonprofit 6
858 338 (72.  769 (72.

or patient demography, except for  Government 1 625 095 (17.  410 (16.

the OIG's remedial efforts to 
Chi-square 0.5, 2 df, P=0.798.

classify unknowns by race. 
(Appendix 4). 
Metropolitan 7 270 147 (76.55) )1  845 (75. 
Non-metropolitan 2 236 208 (23. 606 (24. 
The representativeness verification 
Chi-square 2.  , 1 df, P=0. 161. 
also checked for response bias by 
comparing the 2 451 "sample 
Patient demography 
discharges with the 229 nonsample  64 years 940
650 (9.  232 (9. 
discharges, excluded because no  74 years 3 
65- 932 293 (41.4)  007 (41.1) 
medical records matched to these  84 years 3 
75- 263 952 (34.  854 (34. 
/ bils. Larger hospitals lost  85+ years 1
369,466 (14.4)  358 (14. 
more of their records 
. significantly  Chi-square 0.  , 3 df 860. 
, P = 0.
than did smaller hospitals. The 
Male 4
more voluminous and complex

304 256 (45.3) 1 094 (44.

medical records systems of larger  Female 5
202 105 (54.7) 1 357 (55.4)

hospitals probably offered greater 
Chi-square 0.4, 1 df, P=0.523.

opportunity for charts to 
White 8
disappear: more personnel had 
Black 822671 646 (86. 205 (90.
access to the files, more 
Other 150 204 (8.  188 (7.

departments requested the charts 
380 (1.6)  35 (1.4)

larger record rooms had more  Unknown 267 
131 (2.  23 (0.

shelves on which to misfie charts 
Chi-square 30.  , 3 df, Po:O.OOO1.

more patients had the same 
names, etc. (Appendix 5). 
Total  506 361 . (100.0) 2 451 (100. 
Unsurprisingly, response bias also 
totals to 9 
. Hospital demography  506 365 
occurred for hospital demographic 
because six bil lacked data on hospital control. 
characteristics that correlated with 
hospital size. Metropolitan
 Table 1: Representativeness of sample bils by 
hospitals and teaching hospitals
 hospital and patient demography, 1988 
tended to have more beds.  Therefore, they also had more nonresponses. The response bias in metropolitan 
(Mantel-Haenszel1.6, 1 df, P=0.20) and teaching hospitals (Mantel-Haenszel1.4, 1 df
P=0.23) disappeared upon controllng for hospital size. In contrast, hospital control 
produced no significant response bias. 
No response bias occurred with respect to age or sex. The OIG's reclassification of 
unknowns identified significantly more whites. Controllng for hospital size did not 
remove this nonresponse bias. However, upon excluding nonresponses, the sample 
stil accurately represented all discharges with respect to hospital demographic 
characteristics.  FINDINGS

DRG CODING EROR REDUCED

Hospital  Proportion:! (n) 
Upon blinded ICD- CM reabstraction 
demography  standard error 
14.7 :! 0.7 percent of discharges had 
coding errors that changed their DRGs.  99 beds 17.
0 :! 1.  (359) 
The standard error of 0.7 indicated this  100-299 beds 14.9 :! 1.2 (893)
point estimate to be quite precise, a  300+ beds 13.9 :! 1.0 (1 199) 
secondary effect of the sample size. This 
Chi-square 2.  , 2 df, P=0.351. Phi 0.029. 
proportion was significantly lower than the 
20.8 :! 0.5 percent errors found in 1985  Teaching  1 (1,
15.5 :! 1.  008)
(1985-1988 difference = 0.061, 95% CI  Nonteaching 14.
2 :! 0.9 (1 443) 
043 to 0.079). (Table 2). 
Chi-square 0.  , 1 df, P=0.383. Phi 0.018. 
No hospital demographic characteristics  Profit 17.
3 :! 2.  (272)
had a significant effect upon the  Nonprofit 14.
1 :! 0.8 (1 769)
proportion of DRG coding errors.  Government 15.6:! 1.8 
(410) 
Smaller hospitals appeared to have higher 
Chi-square 2.  , 2 df, P=0.339. Phi 0.030. 
proportions of miscodes, but this apparent 
difference did not attain statistical  Metropolitan 14.9 :! 0.8 (1 845) 
significance. (Appendix 6). 
Nonmetropolitan 14.4 :! 1.4 (606) 
Chi-square 0.  , 1 df, P=0.766. Phi 0.006. 
Similarly, no patient characteristics 
/significantly affected the proportion of 
Patient demography 
.' DRG coding errors. Younger patients  64 years 
16.4 :! 2.4  (232) 
appeared to have higher error rates, but 
65-74 years 14.
9:! 1.1  ( 1007) 
this difference also failed to attain 
75-84 years 14.6 :! 1.2  (854)
statistical significance. (Appendix 7).  85+ years 
13.4 :! 1.8  (358) 
Chi-square 1.0, 3 df, P=0.794.  Phi 0.020. 
Crosstabulations of demographic

Male 14.
characteristics for interaction potential

5 :! 1.1 
(1094)
identified no credible effects. (Appendix  Female 14.
9 :! 1.  (1357)
8). 
Chi-square 0.  , 1 df, P=0.807. Phi 0.005. 
NUERS  White 14.
EQUAL  OF DRG ERRORS  Black 
OVE-REIMURE AN UNER 8 :! 0.  (2205)
Other 1414..4 :! 2. (188)
REIMURSE 
3 :! 6.  (35)
Unknown 8.
7 :! 6.  (23) 
The 361 DRG errors divided evenly

Chi-square 0.  , 3 df, P=0.871.  Phi 0.017. 
between errors that had over-reimbursed

the hospital (50.7 :! 2.6 percent) and
 Total  14.7 :! 0.  (2451) 
under-reimbursed the hospital 
(49.3

percent). This inspection s proportion of
 Table 2: Proportion of coding errors by 
over-reimbursements differed significantly  hospital and patient demography, 1988  from the 61.7 :t 1.4 percent for  Over-re 
Under-re
1985 (1985-1988 difference = Hospital  imbursed imbursed  Total 
110, 95% CI 0.051 to 0.  n (%) 
168).  demography  n (%)  n (%) 
(Table 3). 
99 beds  2) 
For-profit hospitals over- 299 beds 31 (50.8) 30 (49.6)  61 (100. 
100- 71 (53.4) 62 (46. 133 (100. 
reimbursed themselves the  300+ beds 
81 (48.5) 86 (51.5) 167 (100. 
more than did other 
tyes of Chi-square 0.  , 2 df, P=0.703. Phi 0.044. 
hospitals. However, these 
differences did not attain  Teaching  4) 
79 (50.6) 77 (49. 156 (100.
statistical significance. This  Nonteaching  3) 
104 (50.7) 101 (49. 205 (100. 
trend applied across all 
Chi-square 0.  , 1 df, P=0.986. Phi 0.001. 
hospital characteristics. The  Profit 
6) 
direction of coding error also 
27 (57.4) 20 (42. 47 (100.

exhibited no signifcant trend Nonprofit  8) 
123 (49.2) 127 (50. 250 (100.

by patient characteristics. This Government 
33 (51.6) 31 (48.4) 64 (100.

result suggested that little net 
Chi-square 1.2, 2 df, P=0.577. Phi 0.055.

over-reimbursement occurred

because of coding direction.  Metropolitan  6) 
138 (50.4) 136 (49. 274 (100.

Nonmetropolitan 45 
(51.7) 42 (48.3) 87 (100.
DRG CREP ELIMATED 
Chi-square 0.  , 1 df, P=0.825. Phi - 012. 
Ths 
inspection used the case- Patient demography  3) 
mix index (CMI) to calculate  64 years  7) 
17 (44. 21 (55. 38 (100. 
the overall financial effect of  74 years  3) 
/ DRG coding errors. The CMI  65-84 years 77 (51. 73 (48.27))  150 (100. 
75- 66 (52.8) 59 (47.1) 125 (100.
. quantified the complexity of
 85+ years 
23 (47.9) 25 (52. 48 (100. 
PPS discharges by annually 
MChi-squaare l0. e, 3  df, P=0.817. Phi 0.051.
averaging the relative weights 
of all bils submitted by each  5) 
Female 85 (53.5) 74 (46. 159 (100.

hospital. Those hospitals with 
98 (48.5) 104 (51.5) 202 (100.

higher mean relative weights 
Chi-square 0.  , 1 df, P=0.351. Phi - 049. 
served Medicare patients with  White 
more complex conditions and  Black 
that therefore consumed more  Other1 66 (50.8) 161 (49.  327 (100.
14 (51.09)) 1 3 (48.  27 (100.
resources. This inspection

calculated CMI as (1)
 Unknown 2 (40.0) 3 (60. 5 (100. 
submitted to the Fls for
 1 (50. 1 (50.  2 (100.

Chi-square 0.  , 3 df, P=0.970. Phi 0.026. 
reimbursement, (2)

reabstracted by the AMRA on 
Total  183 (50.7) 178 (49.  361 (100.
a blinded basis, and (3) the 
difference or mean weight  Table 3: Direction of DRG errors by hospital and 
change due to coding  patient demography, 1988 
inaccuracy.  Hospital  Mean + standard error  (n)
demo  Before  Afer  Change 
99 beds  1.0914 :t 0.0312  1.0889:t 0.0312 - 0025:t 0.0139  (359)

100-299 beds  3285 :t 0.0314  1.3335:t 0.0311  0049:t 0.0116  (893)

300+ beds  3576 :t 0.0289  1.3595:t 0.0285  0019:t 0.0106  199)

Teaching  3851 :t 0.0327  1.3841:t 0.0322 - 001O:t 0.0125  008) 
(1,
Nonteaching  1.2542 :t 0.0222  1.2590:t 0.0222  0047:t 0.0081  443) 
(1,
Profit  1.3112 :t 0.0605  1.3274:t 0.0621  0162:t 0.0207  (272)
Nonprofit  1.3304 :t 0.0226  1.3333:t 0.0223  0028:t 0.0085  769)
Government  1.2095 :t 0.0383  1.2005:t 0.0378 - 0090:t 0.0145  (410) 
Metropolitan  3479 :t 0.0230  1.3508:t 0.0227  0029:t 0.0086  845) 
Nonmetropolitan  1.1868:t 0.0293  1.1874:t 0.0291  0006:t 0.0107  (606) 
Patient demo  phy 
1.2958 :t 0.0644  1.3249:t 0.0655  0291:t 0.0215  (232) 
65- 1.3769:t 0.0329  1.3632:t 0.0319 - 0137:t 0.0120  007) 
75- 1.2535 :t 0.0291  1.257:t 0.0292  0035 :t 0.0110  (854)
85+  1.2523 :t 0.0374  1.2799:t 0.0392  0275:t 0.0161  (358) 
Male  1.3613 :t 0.0298  1.3589:t 0.0294 - 0024:t 0.0109  094)
Female  1.2651 :t 0.0240  1.2713:t 0.0238  0062:t 0.0090  357) 
(1,
White  1.3180 :t 0.0201  1.3192:t 0.0199  0012:t 0.0074  205) 
Black  1.1838:t 0.0544  1.1865:t 0.0537  0026:t 0.0241  (188)
Other  1.4152 :t 0. 1598  1.4890:t 0.1603  0737:t 0.0538  (35)
Unknown  1.2028:t 0.1769  1.2053:t 0.1762  0025:t 0.0097  (23) 
Total  1.3080 :t 0.0188  1.3104:t 0.0186  0023:t 0.0070  451) 
Table 4: Estimated case-mix index change by hospital and patient demography, 1988 
After reabstraction, the CMI increased 0.0023 :t 0.0070, not a statistically significant 
difference. Hospitals slightly under-reimbursed themselves. This CMI increase 
differed significantly from the previous inspection s over-reimbursement, a 0.0194 :t 
0060 CMI decrease (1985-1988 difference = 0.0171, 95% CMI 0.0158 to 0.0184). 
(Table 4). 
This inspection found that only small, teaching, and government hospitals continued to 
over-reimburse themselves. (Appendix 13). Smaller and government institutions had 
lower absolute CMls, while teaching institutions had higher absolute CMls. 
(Appendices 9 and 11).  Discharges of patients aged 65-74 and males over-reimbursed the hospitals. 
(Appendix 14). These groups of patients also had higher absolute CMls than other 
patient demographic categories. (Appendices 10 & 12). 
DRG OVER-REIMUREMNT ELIATED 
Hospital 
$ milion :t  Number 
. Exrapolating this inspection s results  demography  standard error  of bils 
to all 10.8 milion bils, Medicare 
under-reimbursed hospitals by $69. 
99 beds  14.8 :t 51.5  333 250 
milion. This difference amounted to  100-299 beds  59.4 :t 121.
 454 578 
only 0. 1 percent of the $52 bilion in 
23 In contrast  300+ beds  26.0 :t 156.  718 527 
1988 PPS expenditures.
the previous inspection found PPS 
Teaching  13.4 :t 158.
 076 175 
over-reimbursement of $308 millon or 
Nonteaching  80. 1 :t 131.  430 180 
1.9 percent of 1985 PPS disbursements. 
(Table 5). 
Profit  51.0 :t 62.  022 922 
Nonprofit  58.8 :t 180.  858 338 
Hospital and patient demographic 
Government  42.6 :t 69.  625,095 
trend largely paralleled this trend. 
, teaching, and government 
Small Metropolitan 67.
0:t 195.4  270 147 
8 milion 
hospitals received up to $70. N6onmet4ropoli tan 3.6:t 63.4  236 208 
in over-reimbursement from DRG 
coding errors. (Appendices 15 and 16).  Pat7ient 4dem og-raphy
80.5 :t 62.  940 650 
MIS-PECIFCATION UNER
65-84 461.71.4 :t 145.5  932 293 
/ REIMURSES
REEQUECIG OVE 875-5 + 113.9 :t 109.  263 952 
9 :t 66.4  369 466 
REIMURSES 
Male  30.8 :t 144.  304 256 
Each stage of the reimbursement 
Female  99.0:t 144.  202 105 
process had the potential for 
introducing error into the PPS. When 
White  32.7 :t 188.  261 646 
performing its reabstractions, the 
Black  6.4 :t 62.
 827 204 
AMRA identified the reason for each 
Other  32.4 :t 24.  150 380 
DRG error. 
Unknown  8 :t 7.  267 131 
Mis-specification: The attending 
Total  69.8 :t 203.  506 361 
physician wrote down the wrong 
narrative diagnoses or procedures on  Table 5: Net financial change by hospital and 
the attestation.  patient demography, 1988 
Miscoding: The medical records department selected an incorrect ICD-
, numeric 
code for a correct attestation. 
Resequencing: The biling department substituted a secondary diagnosis for the 
correct, principal diagnosis.  Reason  Subtotal  Total 
n (%)  n (%)

MIS-SPECIFICATION 
227 (63.

Changed principal diagnosis 
75 (20.

Altered principal diagnosis, more or less specific  30 (8.

Added complication-comorbidity or other diagnosis  46 (12.

Deleted complication-comorbidity or other diagnosis  36 (10.

Added operating room procedure 
19 (5.

Deleted operating room procedure 
14 (3.

Changed operating room procedure 
7 (1.9)

MISCODING 
33 (9.

Change due to ICD- CM rule  30 (8.

Change due to ICD- CM rule, changed C.c. status  1 (0.

Change due to ICD- CM rule, changed OR status  2 (0.

RESE  UENCING 
96 (26.

Moved secondary diagnosis to first diagnosis  71 (19.

Changed codes to more or less specific  15 (4.

ICD- CM code differs 
10 (2.

OTHER 
5 (1.4) 
Changed destination  1 (0.3) 
. Provider-FI made data entry error in DRG 
4 (1.1) 
TOTAL 
361 (100. 
Table 6: Reasons for errors affecting DRG assignment, 1988 
In addition 352 other coding changes did not alter the DRG and did not count as 
, 1 
errors for the purposes of this 
study. (Table 6). 
Narrative changes accounted for 63.2 percent of DRG errors. Examples of mis
specification included wrting down the wrong principal 
diagnosis; selecting too
nonspecific a principal diagnosis; and adding or deleting a complication
, comorbidity,
or operating room procedure. 
Miscoding made up 9. 1 percent of the DRG errors. These changes primarily took the 
form of changes in the principal diagnosis, rather than of complications, comorbidities 
or operating room procedures. A few errors represented the AMRA reviewers 
disagreeing with the providers' assigned discharge destinations or apparent 
tyographical errors. 
Resequencing comprised 26.6 percent of the DRG errors. In all cases, the 
reviewers in all cases disagreed with the providers listing sequence. In most cases, the  biling department had substituted a secondary diagnosis for the correctly attested and 
coded principal 
diagnosis. In other cases, the diagnosis should have been more 
specific. ICD- CM ruling changes accounted for the remaining sequence changes. 
Mis-specification significantly n (%)  Over-re- Under-re- Total

under-reimbursed hospitals; while 
imbursed imbursed

resequencing significantly over-

reimbursed them. Thus, the 
Mis-specification  98 (43.2) 129 (56.8)227 (100.

attending physicians select their  5) 
Miscoding  18 (54. 15 (45.5) 33 (100.

patients' diagnoses and 
Resequencing  64 (66.07) )3 2 (33.3) 96 (100.

procedures with caution, earning 
Other 
Total  3 (60. 2 (40.0) 5 (100.

their hospitals less

reimbursement than they should 
183 (50.7) 178 (49.3)361 (100.
have received. The biling 
Chi-square 15.  , 3 df, P=0.002. Phi 0.206.
department behaved more 
Table 7: Reason for DRG changes by direction of 
aggessively, obtaining greater 
reimbursement that the PPS  DRG change, 1988 
entitled their employers to 
receive. Either the hospitals had greater influence over employees, or the employees
identified closely with the economic interests of the hospital. The attestation 
requirement apparently deterred up coding due to mis-specification, but the sentinel 
effect of Peer Review Organization surveilance did not fully prevent over-

reimbursement due to resequencing. (Table 7). 
These two trends, mis-specification resulting in under-reimbursement and resequencing 
/ causing over-reimbursement, offset each other. So, overall hospitals received the 
. correct reimbursement. This inspection cannot predict whether this equilbrium will 
continue in the future. 
CERTAI DRGS AR MORE SUSCEPTLE TO ERROR 
In this random sample of discharges, vascular disorders such as heart failure, angia
stroke, and arrhythmias cause Medicare hospitalizations most frequently. Overall
, 28
of the 476 DRGs accounted for half of the total bils, and 10 DRGs accounted for 28. 
percent of all bils. Most coding errors fell into these DRGs, but not in direct ratio to 
the DRGs' volume. (Table 8). 
This report identified DRGs with high proportions of coding errors by dividing the
number of errors by the frequency of bils for specific DRGs. Many of these DRGs 
covered vague or nonspecific diagnoses such as atherosclerosis (DRG 
132), other
circulatory system procedures (DRG 120), respiratory signs and symptoms (DRG 99), 
and other nervous system disorders (DRG 34). This indeterminateness suggests 
inherent ambiguities in medical taxonomy. For example, DRG 99 includes apnea 
dyspnea, hemoptysis, hypercapnia, pleurodynia, stridor, and ventilatory failure. (Table 
9).  pectoris 
DRG description 
failure and shock  n (%) 
127 Heart 
133 (5.4)
140 Angina 
14 SSpeicimfic cperelberov apscunlare disuordmers eoxcnepti TaIA  89 (3.
89  75 (3.
74 (3.
91862  EBsorpohanjgciotish, igtaiissntr oainntetsdt in aapls, tahnrdm moiasc ewlcliatnheeo ucs oddimgesptuilviec raditsieoordner ss  66 (2.
63 (2.
209 Major 
15 OTrantsiehnt eiscrhem ic 1att
 acks 55 (2.
47 (1.9)
138 Cardiac arrhythmia and conduction disorders 
45 (1.
296 Nutritional and miscellaneous metabolic disorders with complications 
44 (1.
760 (71. 
Total 
451 (100. 
Table 8: DRGs biled most 
frequently, 1988 
DRG description 
Miscoded 
Number (%) 
132  Atherosclerosis 
3 (75. 
413  Myeloproliferative 
4 (66.

185  Dental except extractions 
2 (66.

120  Other circulatory system procedures 
3 (66.

! 99  Respiratory signs and symptoms 
5 (62.

403  Lymphoma and nonacute leukemia 
3 (60.

Other nervous system disorders 
3 (60.

Other 
420  341 (14.

Total 
451  361 (14. 
Table 9: DRGs with high proportions of coding errors
, 1988 
Over-reimbursement concentrated in selected DRGs and certain 
tyes of hospitals.
This report identified DRGs with maxmum 
savings potential by multiplying the error 
frequency by reimbursement change for each DRG. 
Although this inspection found
no overall over-reimbursement to hospitals, certain DRGs stil significantly over-
reimbursed the hospitals. In particular, 13 DRGs each had over $20 milion in 
projected overpayments. This group consisted primarily of DRGs with operating room 
procedures, probably because of their high relative 
weights. (Table 10). 
Additionally, small and for-profit hospitals made more errors that over-reimbursed 
themselves than did other tyes of hospitals. This net over-reimbursement totaled 
$842.2 milion.  DRG description 
Over-reimbursement
$ per 
$ milion 
discharge total 
104  Cardiac valve procedure with pump & cath  4915 
81.1 
468  Unrelated operating room procedures  1128 78.

475  Respiratory system diagnosis with ventilator  791 49.

110  Major reconstructive vascular procedures  682 47.

191  Major pancreas, liver, & shunt procedures  3313 43.

154  Stomach, esophageal, & duodenal procedures  1114 40.

Pulmonary edema & respiratory failure  571 37.

Respiratory system operating room procedures  764 25.

Respiratory neoplasms  306 24.

121  Myocardial infarction discharged alive
 189 23.

415  Operating room procedure for infection
 858 22.

148  Major large & small bowel procedures
 202 22.

217  Wound debridement & skin graft
 333 22.

Other 
235  263 -587.

Total 
451  69.

Table 10: DRGswith maxmum 
savings potential, 1988
 RECOMMENDA TIONS

~ The Peer Revew Organtions should contiue their sureilance of hospita

cog 
for DRG reimburement accurcy.

The attestation requirement appears to have .deterred over-reimbursement due to 
mis-specification by attending physicians, causing their hospitals to be under-
reimbursed. However, the sentinel effect did not fully prevent over-reimbursement 
due to resequencing by hospitals. Although these two trends approximately offset 
each other, this equilbrium may not continue in the future. 
The Agency for Health Care Policy Research plans to reabstract the ICD-
codes from a large sample of Medicare charts to determne their diagnostic 
accuracy for health servces research purposes. Using 1991 data, grouping these 
ICD- CM codes to DRGs, and selecting reasons for any differences would provide 
a third time point with which to track trends in reimbursement accuracy. The OIG 
supports this effort. 
COMM 
AGENCY 
In its May 29, 1992 comments to the draft of this inspection, the HCF A concurred 
with the OIG recommendation. The HCFA noted that the improvement in DRG 
coding accuracy may be attributable to increased hospital experience with PPS, PRO 
review, and HCF A educational efforts. 
/ The HCF A also made a number of technical comments. Based on these comments 
the OIG made several changes to this inspection. The full text of the HCF 
comments appear as an appendix.  ENDNOTES 
1. Schweiker R S. Report to Congress: hospital prospective payment for medicare.

Washington, DC: U.S. Department of Health and Human Servces
, 1982.

2. Social Security Amendments of 
1965. Pub. L. No. 89- , 79 Stat 286 (1965). 
3. Social Security Amendments of 
1983. Pub. L. No. 98- , 97 Stat 65 (1983). 
4. Commission on Professional and Hospital Activities. International 
classification of

diseases, 9th edition, clinical modifications. Ann Arbor, MI: Edward Brothers
, 1980.

5. Fetter R B, Shin Y & Freedman A T. The new ICD- CM diagnostic
, Averill R 
related groups classification scheme user s manual: fial report. New Haven, Cf: Yale
School of Organization and Management, Health Systems Management Group, 
1981. 
6. Fed Reg, July 31, 1985; 50 (147): 31038. 
7. Shriners' Hospital for Crippled Children -- Colorado Corporation --
Conveyance.

Pub. L. No. 94-505; October 15, 1976: Title II  201-07.

8. Delaney A M & Hsia D C, eds. 1985 national DRG validation study. Lexington 
MA: Health Data Institute, 1987. Report prepared for the Office of Inspector 
General. U.S. Department of Health and Human Servces; contract HHS-
100-87
0015. 
9. Hsia D C, Krshat W M, Fagan A B, Tebbutt J A, & 
Kusserow R P. Accuracy of 
diagnostic coding for medicare patients under the prospective-
payment system. N
Engl J Med, 1988; 318: 352-55. 
10. Health Care Financing Administiation, U.S. Department of Health and Human 
Servces. Medicare program: prospective payments for medicare inpatient hospital 
servces. Fed Reg, September 1, 1983; 48: 39752-39886. 
11. Health Care Financing Administration, U.S. Department of Health and Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment 
system and fiscal year 1985 rates. Fed Reg, August 31, 1984; 49: 34728-90. 
12. Health Care Financing Administration, U.S. Department of Health and Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment 
system and fiscal year 
1986 rates. Fed Reg, September 3, 1985; 50: 35646-759. 
13. Health Care Financing Administration, U.S. Department of Health and Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment 
system and fiscal year 
1987 rates. Fed Reg, September 3, 1986; 51: 31454-603.  14. Health Care Financing Administration, U.S. Department of Health and Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment 
system and fiscal year 1988 rates. Fed Reg, September 1, 1987; 52: 33033-165. 
15. Health Care Financing Administration, U.S. Department of Health and Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment
system and fiscal year 1989 rates. Fed Reg, September 30, 1988; 53: 38475-640. 
16. Health Care Financing Administration, U.S. Department of Health & Human 
Servces. Medicare program: changes to the inpatient hospital prospective payment
system and fiscal year 1990 rates. Fed Reg, September 1989; 54: 36451-589. 
17. Health Care Financing Administration, U.S. Department of Health & Human

Servces. Medicare program: changes to the inpatient hospital prospective payment

system and fiscal year 1991 rates. Fed Reg, September 1990; 55: 35989-6175.

18. Simborg D W. DRG creep: a new hospital-acquired disease. N Engl J Med, 1981; 
304: 1602-04. 
19. Carter G M & Ginsburg P B. The Medicare case mi index increase: medical 
practice changes, aging, and DRG creep. Santa Monica, CA: RA Corporation

1985. Publication no. R-3292-HCFA.

20. Thomas J W & Longo D R. Application of severity measurement systems for
hospital quality management. Hospital and Health Servces Administration
, 1990: 35 
/ (2): 221-23. 
21. Division of Information Analysis, Offce of Statistics and Data Management

Bureau of Data Management and Strategy, Health Care Financing Administration

S. Department of Health & Human Servces. 1989 HCFA Statistics. Baltimore

MD: Health Care Financing Administration, 1989: 16 & 34.

22. Ruther M, Reily T W, Silverman H A, & Abbott D B. 
Medicare and Medicaid 
data book, 1990. Baltimore, MD: Offce of Research and Demonstrations
, Health
Care Financing Administration, U.S. Department of Health & Human Servces
, 1991:
15. HCFA pub. no. 03314. 
23. Division of Information Analysis, Office of Statistics and Data Management

Bureau of Data Management and Strategy, Health Care Financing Administration

S. Department of Health and Human Servces. 1989 HCFA statistics. Baltimore

MD: Health Care Financing Administration, 1989: 25. HCFA publication no. 
03294.
 Appendix 1: Contract inormation 
Contractor 
BOTEC Analysis Corporation 
1698 Massachusetts Avenue 
Cambridge, MA 02138 
Project Offcer 
David Hsia, J.  , M.  , M. 
Offce of Inspector General 
330 Independence Avenue 
Washigton, D.C. 20201 
Contract 
HHS-100-90-0023 
Fir-
Fixed Price Contract 
$203 257  Appendix 2: Project participants 
OIG

Cathaleen A Ahern, B.

Evan J. Buckigham, B.

David C. Hsia , M.  , M.

, J. 
Thomas F. Komaniecki, M.

W. Mark Krshat, M.

Lida M. Moscoe, B.

Brian P. Ritchie, B.

Barr L. Steelef

John M. Traczyk, B. 
HCFA

Timothy F. Greene, M.  , M.B.A

Stephen F. Jencks, M.

Michael R. McMullan, M.

Harr L. Savitt, Ph.

Jeanette M. Smith, M.  , M.

Malcolm A Sneen, B.S.

RAN 
Corporation

Haya P. Rubin, M.  , Ph.

Baxer-Health Data Institute 
/ Patricia J. Baxer, R. 
. Patricia Cassidy-Tsnosas, R. 
Anette M. Delaney, R.  , M.

Ellen B. Inghileri, R.

Janet Mathews, AR.

Laurie H. Moore, R.

Claire Shannon, AR.

Michele A. Wiese, B.

Margret K. Amatayakul, M.  , R.

Mary Converse, R.

Nicholas J. Cotsonas, M.

1. Institutions appear in chronological order of involvement. 
2. Now at Health Audit Servces, Ellcott City, MD. 
3. Now at the Journal of the American Medical Association, Chicago, IL. 
4. Now at Johns Hopkis Medical Institutions. 
5. Ceased operations February 16, 1990. 
6. Outside contractor.  Linda Ertl, R.

Rita M. Finnegan, R.

Desla Mancila, A.R. T.

Barbara Manny, R.

Sonia Martyiuk, R. 
Toula Nicholas, A. 
Charlotte Razor, R.

LouAn Schraffenberger, R.

Lynn Smetko, R.

Dawn Smith, AR.

Joan Zacharias, A.

BOTEC Analysis Corporation 
Geraldine M. Berenholz, R. 
Andrew H. Chalsma, B. 
David P. Cavanagh, M.  , Ph. 
Janet W. Knight, R.  , Ph. 
Amy L. Lockwood, B.A.  Appendix 3: Calculation formulas 
cog 
Proporton of bil with  errors 
Appendixes 6-7 display for various subsets of hospitals and patients, the proportion of
sample discharges whose DRGs were changed by AM (i.e.
, whose origial DRG 
was incorrect). Since the 1988 Study self-weights, these proportions comprise unbiased
direct estimates of the proportion of all CY  bilg 
1988  records withi each subset 
which have an incorrectly coded DRG. Each presentation includes the proportion
, its
standard error, and the number of sampled bils in the 
cell. 
Because the proportions in these tables derive from a sample there 
exists a

quantifable possibilty that the actual proportions of all Medicare bils with miscoded

DRGs may difer by some amount from the proportions presented in the 
appendixes.

The standard error is a statistic that allows calculation of the probabilty that the true
population proportion differs from the sample proportion. 
Put over-simply if p is the

sample proportion and s is the standard error, then there is a 95 percent chance that

the true population proportion lies between p - (2.04 * s) and p + (2.04 * s), and

there is a 99 percent chance that the true population 
proportion lies between p - (2.

* s) and p + (2.72 * s). 
The relation among the sample proportion, the standard error, and the number of
sample bils is as follows: assume there are n bils in a subset of the sample and e of
these bils have DRG coding errors. Then the 
sample proportion is: p = e / n. The
standard error is: s = (p * (1 - p) 
/ (n - 1))% 
For example, in Appendix 6 the upper left-most cell 
gives the percent of miscoded 
bils from large, for-profit, teaching hospitals in metropolitan areas. There are eight
records in this subset of the sample. Two of these 
discharges have miscoded DRGs.
Therefore the proportion of DRG coding errors in the sample is p = 2/8 = 0.25 =
25 percent. Ths also comprises the unbiased estimate of the proportion of bilg
records which large, metropolitan, for-profit, teaching hospitals submitted in CY 
1988
and which contained miscoded DRGs. 
The standard error of this proportion is: s = ((0.25 * (1 - 0.25)) / (8 - 1))% = 0.164 = 
16.4 percent. Ths means that there is a 95 percent probabilty that the proportion of
miscoded biling records submitted by all these hospitals in CY 
1988 was between 0 
percent (0.25 - (2.04 * 0. 164)) and 58 percent (0.25 + (2.04 * 0. 164)). There is a 99
percent probabilty that this proportion is 
between 0 percent (0.25 - (2.72 * 0. 164))
and 69 percent (0.25 + (2.72 * 0. 164)). 
Researchers can combine particular cells of these appendixes in the 
followig manner:
if the cells have proportions of biling errors 
and numbers of sample bils n P1 and P2' standard errors of S1 and S
l and n2 respectively; then the combined proportion
errors: Pt = ((n 
* P1) + (n2 * P2)) / (n1 + n )' The standard error of this proportion: 
)) / (n
1 + n
t = ((Pt * (1 - Pt 2 - 1))%  For example, the proportion of errors among biling records submitted by large and
medium, for-profit, teaching hospitals in metropolitan areas is Pt = 
25) + (15 *
((8 * 0.
20)) / (8 + 15) = 0.217 = 21.7 percent. This calculation is based on data from the 
first and thireenth cells in column one of the appendix in the preceding 
example.
This combined proportion has a standard error: S
217 * (1.000 - 0.217)) / (8 +
t = ((0.
15 - 1))% = 0.088 = 8.8 percent. 
Signcace testig 
By calculating the frequencies summaried by these proportions, researchers
constructed the underlying contingency table and calculated its statistical signficance 
measures of the degree of association between dependent and independent variable. 
Appendix 8 displayed the interaction analysis for coding error. 
These calculations deleted certain cases and collapsed certain categories of 
independent variables to simplif the analysis. To decrease the degrees of freedom
this testing ignored bils that coded patient race as "
other" or "unknown." These 58 
cases comprised too small a cell to determine whether billng records with these race 
codes showed statistically significant propensities to miscode DRGs. 
Furthermore it 
did not make sense to combine these biling records 
with biling records with race
codes of either ''white '' or "black". Evidence from other sources suggested that biling
records of "other" and "unknown" differed in significant ways both from 
biling records
of ''white '' and ' 'black'' 
Preliminary analysis suggested that age affected differences in the 
propensity to
/ miscode DRGs, particularly in two age groups. The first comprised patients under 65 
, those eligible for Medicare because of disabilties). 
. (i.e. The second comprised
patients 85 and over (i.e., those patients who were extremely elderly). Therefore we 
recoded patient age into three 
categories for these tables: oe65, 65- , and 85+. 
Table 2 summarizes data from Appendies 6-7. Thus, rather than reporting the
within-cell distribution of cases between miscoded and correctly coded biling records 
these tables report only the proportion of incorrectly coded biling records within each
cell. Researchers can construct the original three-way contingency tables from these 
summary tables if they wish. 
Each of these tables calculates two statistics: chi-square and phi. 
Chi-square measures
only statistical significance. It quantifies the relationship between variables 
poorly.
The phi statistic measures the strength of relationship between 
variables in a table 
better. Phi is the square root of chi-square divided by the number of cases in a table. 
Phi ranges between 0 and 1. The closer phi is to 0 the weaker the relation 
displayed 
in a table. The closer phi is to 1 the stronger the relation.  Ca mi 
index and changes 
Appendixes 9-12 show for various subsets of hospitals and patients the average DRG 
weight or CMI, before and after AMRA reabstraction. This information also includes 
the CMI standard error and cell size. The following formulas calculate the CMI 
assuming n biling records in cell and the ith biling record has a relative weight of w 
then: CMI -= I: Wi / n.  ThisCMI has a standard error: SE =  / nYz where 
 = ((I:
(CMI - Wi)2
) / (n - 1))% 
Appendixes 13-14 calculation of the CMI change used identical formulas, but 
substituted the relative weight after recoding minus the relative weight before recoding 
for the DRG weights. Negative mean values suggest that the original reimbursement 
to be higher than it should have been, while positive values suggest original under-
reimbursement. For individual biling records this calculation provides the change in 
DRG weight. Averaged over a subset of biling records it provides the change in CMI 
as a result of DRG recoding. The diference between the CMI in any cell of a 
before" table and the corresponding cell of an "after" table appears in the same cell 
of the "change" table. Each corresponding cell has the same n. However, no simple 
formula relates the standard errors of corresponding cells. 
Researchers can combine particular cells within any of these appendixes as follows: 
the cells have CMls C  and Cz, CMI standard errors of S
1 and S2' and numbers of 
sample bils n1 and n2 respectively; then the combined CMI:  = (( n ) + (n
1 * C 2 * 
ez)) / cr1 + n2)' This CMI has standard error: St = (((n1 * (n1 -1) * s/) + (n2 * (n2 
1) * S2 )) / ((n1 + n ) * (n1 + n2 - 2)))%. For an explanation of these formulas see 
/ McNemar Q, Psychological statistics, 4th ed., New York, NY: John Wiley, 
1969: 114
. 15. 
For example, the CMI before recoding for biling records submitted by large and 
medium, for-profit, teaching hospitals in metropolitan areas is c  = ((8 * 
1.0205) + (15 
* 1.2991)) / (8 + 15)  1.2022. This calculation is based on data from the first and 
thirteenth cells in column one. The standard error of this CMI is S
t = (((8 * (8 - 1) *
1390 ) + (15 * (15 - 1) * 0.2401 )) / ((8 + 15) * (8 + 15 - 2)))% = 0. 1652. 
Mea change in reimburement 
Appendixes 15-16 show for various subsets of hospitals and patients the average 
change in dollar reimbursement per  would have resulted from correct DRG 
bil that 
coding. Negative means suggest that the government' s reimbursements to providers 
were higher than they should have been, while positive means suggest that the 
government s reimbursements to providers were lower than they should have been. 
other words negative means in these tables suggest that the government has lost 
money as a result of DRG coding errors while positive means suggest that the 
government has gained money as a result of DRG coding errors.  These appendixes incorporate a simplifyng 
assumption: that the actual reimbursement
hospitals receive for patients is the standardized amount times the DRG weight. 
variety of factors can slightly modif the standardized amount including whether a 
hospital is metropolitan or nonmetropolitan, teaching or nonteaching, etc. 
Most of
these modifications have minor overall effects on reimbursement and in the aggregate 
tend to cancel each other. 
The exception is the diference between the standardized amount paid to metropolitan
hospitals versus the standardized amount paid to nonmetropolitan 
hospitals. The
standardized amount to metropolitan hospitals 
averaged $3 118 (current dollars) in CY
1988, whie the standardized amount to nonmetropolitan hospitals averaged $2 
637 
(current dollars) durig the same period. These averages were based on a total of 
10.8 milion billing records. 
The means, standard deviations,. and difference for reimbursement use formulas 
identical to the CMI calculations. Combining cells also uses the same calculations as 
for combining CMI entries. 
Projections of national reimburement change 
Appendixes 17-18 show the total number of bils submitted to HCFA in CY 
1988 for
various subsets of hospitals and patients. These appendixes provide the basis for
projecting total savings or losses due to improper DRG 
coding. Negative amounts 
constitute an estimated loss to the government (over-reimbursement), while positive 
amounts represent too Iowa payment by 
the government (under-reimbursement). 
, Appendixes 19-20 contain the average under-reimbursement or over-reimbursement to 
the government per biling record as a result of DRG 
coding errors for a particular
tye of hospital or patient as well as the standard error. 
The corresponding cell in this
appendix gives the total number of 
bils submitted by this particular tye of hospital or
for this particular tye of patient in CY 1988. Multiplying the average dollar change 
per bil by the corresponding number of bils in each cell estimates the total dollar 
effect on the government. Multiplying the 
standard error per bil by the corresponding
number of bils in each cell produces the standard errors of the dollar projection. 
This technique has one important caveat. The 
1988 Study final sample excluded

certain CY  and certain other CY 
1988 biling records  a priori  1988 biling records

because of nonresponse. Thus the means and standard errors in apply to 
slightly

different populations of biling records from appendixes to appendix. 
Practically this

means that the standard errors in the projections of dollar 
change may actually be a
very small amount smaller than an extremely conservative estimate would make them. 
However, this limitation has no impact upon the 
findings of this study.  Appendix 4: Representativeness of selected discharges, 1988 
Hospital  ulation  Selected  Chi-square 
demo  n (%)
 n (%)

99 beds  333 250 (14.  385 (14.4)  1.6, 2 df, P=0.459 
100-299 beds  454 578 (36.  943 (35. 
300+ beds  718 527 (49.  352 (50.4) 
Teaching  076 175 (42.  130 (42.  , 1 df, P=0.455 
Nonteaching  430 180 (57.  550 (57. 
Profit  022 922 (10.  291 (10.  , 2 df, P=0.983 
Nonprofit  858 338 (72.  933 (72. 
Government  625 095 (17.  456 (17. 
Metropolitan  270 147 (76.5)  038 (76.  , 1 df, P=0.598 
Nonmetropolitan  236 208 (23.  642 (24. 
Patient demo 
64 years  940 650 (9.  254 (9.  , 3 df, P=0.901 
65-74 years
 932 293 (41.4)  110 (41.4) 
75-84 years
 263 952 (34.3)  924 (34.5) 
85 + years  369 466 (14.4)  392 (14. 
/ Male  304 256 (45.3)  202 (44.  , 1 df, P=0.657 
. Female
 202 105 (54.  478 (55. 
White
 261 646 (86.  398 (89.  38.4, 3 df, P-c0.0001 
Black
 827 204 (8.  215 (8.0) 
Other
 150 380 (1.6)  43 (1.6) 
Unknown
 267 131 (2.  24 (0. 
Total  506 361. (100.  680 (100.  not applicable

. Hospital demography totals to 9 506 355 because six bils lacked data on hospital 
control.  Appendix 5: Nonresponses, 1988 
Hospital  Res  onses  Nonres  onses  Chi-square 
demo  phy  n (%)  n (%) 
99 beds  359 (14.  26 (11.4)  27.  , 2 df, Pc:O.OOOl 
100-299 beds  893 (36.4)  50 (21.8) 
300+ beds  199 (48.  153 (66. 
Teaching  008 (41.4)  122 (53.  12.  , 1 df, Pc:O.OOOl 
Nonteaching  443 (58.  107 (46. 
Profit  272 (11.1)  19 (8.  , 2 df, P=0.233 
Nonprofit  769 (72.  164 (71.6) 
Government  410 (16.  46 (20. 
Metropolitan  845 (75.  193 (84.  9.3, 1 df, P=0.002 
Nonmetropolitan  606 (24.  36 (15. 
Patient demo 
64 years  232 (9.5)  22 (9.  1.9, 3 df, P=0.596 
65- 74 years  007 (41.1)  103 (45. 
75-84 years  854 (34.  70 (30. 
85 + years  358 (14.  34 (14. 
/ Male  094 (44.  108 (47.  , 1 df, P=0.462 
. Female  357 (55.4)  121 (52. 
White  205 (90.  193 (84.3)  , 3 df, P=0.032 
Black  188 (7.  27 (11.8) 
Other  58 (2.4)  9 (3. 
Unknown  35 (1.4)  1 (0.4) 
Total  451 (100.  229 (100.  not applicable  Appendix 6: Proportion of DRO coing errors by hospital demography, 1988 
Proportion :I standard errr (n)  Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
99 bes 
Teaching  16.7 :I 16.7 (6)  no  16.7 :I 16.7 (6) 
Profit  Nonteaching  10.0 :I 6.9 (20)  30.3 :I S.l (33)  22.7 :I 5.S (53) 
Teaching & nonteaching  11.5 :I 6.4 (26)  30.3 :I S.l (33)  22.0 :I 5.4 (59) 
Teaching  50.0 :I 50.0 (2)  0 :I 0.0 (1)  33.3 :I 33.3 (3) 
Nonprofit  Nonteaching  25.7 :I 7.5 (35)  17.1 :I 3.4 (123)  19.0 :13.1 (15S) 
Teaching & nonteaching  27.0 :I 7.4 (37)  16.9 :I 3.4 (124)  19.3:1 3.1 (161) 
Teaching  0:1 0.0 (1)  33.3 :I 33.3 (3)  25.0 :I 25.0 (4) 
Government  Nonteaching  15.4 :I 7.2 (26)  11.0 :I 3.0 (109)  11.9 :I 2.S (135) 
Teaching & nonteaching  14.S:I 7.0 (27)  11.6 :I 3.0 (112)  12.2:1 2.S (139) 
Teaching  22.2:1 14.7 (9)
 25.0:1 25.0 (4)  23.1 :I 12.2 (13) 
All  Nonteaching  1S.5 :I 4.3 (Sl)
 16.2:1 2.3 (265)  16.S :I 2.0 (34) 
Teaching & nonteaching  1S.9 :I 4.1 (90)
 16.4:1 2.3 (269)  17.0:1 2.0 (359) 
100-299 bes 
Teaching  20.0 :I 10.7 (15)  no  20.0 :I 10.7 (15) 
Profit  Nonteaching  13.7:1 3.2 (117)  12.5 :I 5.9 (32)  13.4:1 2.S (149) 
Teaching & nonteaching  14.4 :I 3.1 (132)  12.5 :I 5.9 (32)  14.0 :I 2.7 (164) 
Teaching  17.3 :I 3.1 (145)  S:I 4.S (21)
 15.7 :I 2.S (166) 
Nonprofit  Nonteaching  15.4 :I 2.2 (267)  13.2:1 2.7 (159)  14.6:1 1.7 (426) 
Teaching & nonteaching  16.0:1 1.S (412)  12.2 :I 2.4 (180)  14.9 :I 1.5 (592) 
Teaching  27.8 :I 10.9 (lS)  33.3 :I 33.3 (3)  28.6 :I 10.1 (21) 
Government  Nonteaching  13.1 :I 5.0 (46)  14.3 :I 4.2 (70)  13.S :I 3.2 (116) 
Teaching & nonteaching  17.2 :I 4.8 (64)  15.1 :I 4.2 (73)  16.1 :I 3.1 (137) 
Teaching  1S.5 :I 2.9 (17S)  3 :I 5.S (24)  17.3:1 2.7 (202) 
All  Nonteaching  14.7:1 1.7 (430)  13.4 :I 2.1 (261)  14.2 :I 1.3 (691) 
Teaching & nonteaching  15.S :I 1.5 (60)  13.0 :I 2.0 (285)  14.9:1 1.2 (S93) 
30+ bes 
Teaching  25.0 :I 16.4 (S)  no case  25.0 :I 16.4 (S) 
Profit  Nonteaching  22.0:1 6.5 (41)  no case  22.0:1 6.5 (41) 
Teaching & nonteaching  22.5 :I 6.0 (49)  no case  22.5 :I 6.0 (49) 
Teaching  14.5:1 1.3 (703)  7 :I 6.7 (15)  14.4 :I 1.3 (71S) 
Nonprofit  Nonteaching  7:1 1.7 (276)
 1S.2 :I S.4 (22)  9.4 :I 1.7 (29S) 
Teaching & nonteaching  12.9 :I 1.1 (979)  13.5 :I 5.7 (37)  12.9 :11. (1016) 
Teaching  20.0 :I 5.0 (65)  0 :I 0.0 (2)  19.4 :I 4.9 (67) 
Government  Nonteaching  20.4 :I 5.5 (54)  7 :I 7.7 (13)  17.9:1 4.7 (67) 
Teaching & nonteaching  20.2:1 3.7 (119)  7 :I 6.7 (15)  1S.7 :I 3.4 (134) 
Teaching  15.1 :I 1.3 (776)  9 :I 5.9 (17)  14.9 :I 1.3 (793) 
All  Nonteaching  11.9:1 1.7 (371)  14.3 :I 6.0 (35)  12.1 :I 1.6 (406) 
Teaching & nonteaching  14.0 :I 1.0 (1147)  11.5 :I 4.5 (52)  13.9:1 1.0 (1199) 
All hos itals 
Teaching  20.7 :I 7.7 (29)  no  20.7 :I 7.7 (29) 
Profit  Nonteaching  15.2 :I 2.7 (17S)  21.5 :I 5.1 (65)  16.9 :I 2.4 (243) 
Teaching & nonteaching  16.0:1 2.6 (207)  21.5 :I 5.1 (65)  17.3 :I 2.3 (272) 
Teaching  15.1 :I 1.2 (S50)  5.4 :I 3.S (37)  14.7 :I 1.2 (887) 
Nonprofit  Nonteaching  12.S :I 1.4 (57S)  15.1 :I 2.1 (30)  13.6 :I 1.2 (882) 
Teaching & nonteaching  14.2 :I 0.9 (1428)  14.1 :I 1.9 (341)  14.1 :I O.S (1769) 
Teaching  21.4 :I 4.5 (84)  25.0 :I 16.4 (S)  21.7:1 4.3 (92) 
Government  Nonteaching  16.7:1 3.3 (126)  12.0 :I 2.3 (192)  13.S :I 1.9 (31S) 
Teaching & nonteaching  1S.6 :I 2.7 (210)  12.5 :I 2.3 (200)  15.6:1 1.S (410) 
Teaching  15.S :I 1.2 (%3)  9 :I 4.3 (45)  15.5 :I 1. (100) 
All  Nonteaching  13.S :I 1.2 (882)  14.S:I 1.5 (561)  14.2 :I 0.9 (1443) 
Teaching & nonteaching  14.9 :I O.S (1845)  14.4 :I 1.4 (60)  14.7:1 0.7 (2451)  Appendix 7: Proportion of DRO coing errors by patient demography, 1988 
Proportion :t standard errr (n) 
Male  Female  Male & female 
0-0  vea 
White  19.5 :I 3.7 (113)  16.2:t 4.5 (68)  1S.2 :t 2.9 (lSl) 
Black  95:1 6.6 (21)  6 :t 5.6 (lS)  7 :t 4.3 (39) 
Other  12.5:1 12.5 (S)  33.3 :t 33.3 (3)  1S.2:t 12.2 (11) 
Unknow no case  0:t 0.0 (1)  0:t 0.0 (1) 
All race 17.6:1 3.2 (142)  14.5 :t 3.7 (90)  16.4 :t 2.4 (232) 
65-74  vea 
White  14.0:t 1.6 (45S)  16.2:t 1.7 (46)  15.1 :t 1.2 (922) 
Black  13.3 :I 6.3 (30)  15.S :t 6.0 (38)  14.7 :t 4.3 (68) 
Other  0 :t 0.0 (5)  12.5 :t 12.5 (S)  7 :t 7.7 (13) 
Unknow 0.0 :I 0.0 (3)  0:t 0.0 (1)  0 :t 0.0 (4) 
All race 13.7:1 1.5 (496)  16.1 :t 1.6 (511)  14.9 :t 1. (1007) 
75-8  vea 
Whte  13.7 :t 1.9 (328)  15.4 :t 1.7 (456)  14.7 :t 1.3 (784) 
Black  15.4 :I 7.2 (26)  1S.5 :t 7.6 (27)  17.0:t 5.2 (53) 
Other  20.0 :I 20.0 (5)  0 :I 0.0 (2)  14.3 :t 14.3 (7) 
Unknow 0.0:1 0.0 (4)  0:t 0.0 (6)
 0 :t 0.0 (10) 
All race 13.S:t 1.S (363)  15.3 :t 1.6 (491)  14.6 :t 1.2 (S54) 
S5+  ears

Whte  17.1 :t 4.2 (S2)
 11.0 :t 2.0 (23)  12.6 :t 1.9 (31S) 
Black  25.0 :t 16.4 (S)
 15.0 :t S.2 (20)  17.9 :t 7.4 (28) 
Other  0 :t 0.0 (2)
 50.0 :t 50.0 (2)  25.0:t 25.0 (4) 
Unknow 0.0:t 0.0 (1)
 28.6 :t 1S.4 (7)  25.0 :t 16.4 (S) 
Al race 17.2:t 3.9 (93)
 12.1 :t 2.0 (265)  13.4 :I 1.S (35S) 
AII ae:es

White  14.S:t 1. (9S1)
 14.9 :t 1.0 (1224)  14.S :t O.S (2205) 
Black  14.1 :t 3.S (S5)
 14.6 :t 3.5 (103)  14.4 :t 2.6 (188) 
Other  10.0 :t 6.9 (20)
 20.0 :t 10.7 (15)  14.3 :t 6.0 (35) 
Unknown 0.0 :t 0.0 (S)  13.3 :t 9.1 (15)  7 :t 6.0 (23) 
All race 145:t 1.1 (1094)  14.9 :t 1.0 (1357)  14.7:t 0.7 (2451)  Appendix S: Interaction potential by hospital and patient demography, 1988 
Proportion (n) 
Race  be siz  99 bes  100-29 bes  30+ bes  Total 
Whte
 17.1S (326)  15.15 (S12)  13.S7 (1067)  14.S3 (2205) 
Black
 10.00 (20)  11.11 (63)  17.14 (105)  14.36 (188) 
Total
 16.76 (34)
 14.86 (S75)
 14.16 (1172)
 14.79 (2393) 
((CPhhii-)s
quare)
 ((00..609465, )2   dC,  P=O.40)
 ((00..705239, )2   P=0.385)
 ((00.8.4227, )2   P=0.359)
 ((00..0300,)   dC,  P=0.862) 
Race  loction  Metro  litan
 Nonmetro  litan
 Total 
White  14.S5 (1657)
 14.7S (548)
 14.83 (2205) 
Black  17.45 (149)  56 (39)  14.36 (188) 
Total  15.06 (180)  13.97 (5S7)  14.79 (2393) 
(Chi-square)
 (0.724, 1 dC,  P=0.395)  (4.522, 1 dC,  P=0.33)  (0.030, 1 dC,  P=0.862) 
(Phi)
 (0.20)  (0.08)  (0.00) 
Race  control  Non rofit  Profit  Government  Total 
Whte  14.37 (1621)  17.01 (241)  15.45 (343)  14.S3 (2205) 
Black  13.27 (113)  22.73 (22)  13.21 (53)  14.36 (188) 
Total  14.30 (1734)
 17.49 (263)
 15.15 (396)  14.79 (2393) 
((PChhii)- suare)  ((00..10004,) 2   dC,  P=0.747)
 ((00..405462, )2   P=0.499)
 ((00..108201 )  dC,  P=0.671)  ((00..0300 )  dC,  P=0.862) 
Race  teachi
 status  Teachin  Nonteachin  Total 
White
 15.S2 (885)  14.17 (1320)  14.83 (2205) 
Black
 15.15 (99)  13.48 (S9)  14.36 (188) 
Tota
 15.75 (984)
 14.12 (140)  14.79 (2393) 
(Chi-suare)
 (0.30, 1  P=0.863)
 (0.032, 1  P=0.S5S)  (0.030,  P=0.862) 
(Phi)
 (0.00)  (0.005)  (0.00) 
Race  Male
 Female
 Total

White
 14.7S (9S1)
 14.S7 (1224)
 14.S3 (2205)

Black
 14.12 (S5)  14.56 (103)  14.36 (188) 
Total
 14.23 (106)  14.S5 (1327)  14.79 (2393) 
(Chi-square)
 (0.27  P=0.869)  (0.007, 1  P=0.933)  (0.30, 1  P=0.862) 
(Phi)
 (0.005)  (0.002)  (0.00) 
Race  0-6  65-8  S5+  Total 
White  1S.23 (lSl)  14.S9 (1706)  12.5S (31S)  14.S3 (2205) 
Black  69 (39)  15.70 (121)  17.8 (28)  14.36 (188) 
Total  16.36 (220)  14.94 (lS27)  1301 (34)
 14.79 (2393) 
((CPhhii-)s quare) ((20.. 109)  dC,  P=0.107)  ((00..00509,) 2   dC,  P=O.80S)  ((00..603443, )  dC,  P=0.426)  ((00..0300,)  2  P=0.862) 
Sex  bed siz  99 bes  100-299 beds  30+ beds  Total 
Male  16.56 (151)  15.32 (385)  13.77 (530)  14.73 (106) 
Female  16.92 (195)  14.49 (490)  14.49 (642)  14.S5 (1327) 
Total  16.76 (346)
 14.86 (S75)
 14.16 (1172)  14.79 (2393) 
((CPhhii-)s quare) ((00..0000, 52)   dC,  P=0.928)
 ((00..10119,2 )2  dC,  P=0.73O)
 ((00..102110 )  dC,  P=0.728)  ((00.. 002,)  2 dC,  P=0.936) 
Sex  loction  Metro  litan  Nonmetro  litan  Total 
Male  14.61 (801)  15.09 (265)  14.73 (106) 
Female  15.42 (1005)  13.04 (322)  14.S5 (1327) 
Total  15.06 (lS06)
 13.97 (5S7)
 14.79 (2393) 
(Chi-square) (0.232, 1  P=0.63O)
 (0.509, 1 dC,  P=0.476)
 (0.  , 1 dC,  P=0.936) 
(Phi)  (0.011)  (0.029)  (0.002) 
Sex b  control  Non rofit  Profit  Government  Total 
Male  14.53 (771)  19. 13 (115)  12.7S (180)  14.73 (106) 
Female  14. 12 (963)  16.22 (14S)  17.13 (216)  14.S5 (1327) 
Total  14.30 (1734)  17.49 (263)  15.15 (396)  14.79 (2393) 
((CPhhii-)s quare) ((00..00507 )  P=O.Sl1)  ((00.3.3818 ,)  2  P=0.537)  ((01..0464 )  P=0.229)  ((00.. 002)  P=0.936)  . Sex  teachin  status  Teachin  Nonteachin  Total 
Male  16.16 (427)  13.77 (639)  14.73 (106) 
Female  15.44 (557)  14.42 (770)  14.85 (1327) 
Total  15.75 (984)  14.12 (140)  14.79 (2393) 
(Chi-suare)  (0.  , 1 df, P=0.759)  (0.119, 1 df, P=0.730)  (0.06, 1 df, P=O.93) 
(Phil  (0.010)  (0.00)  (0.002) 
Sex  0-6  65-8  S5+

Male  17.91 (134)
 13.90 (842)  17.7S (90)
 14.73 (106)

Female  13.95 (86)
 15.84 (98)  11.33 (256)  14.S5 (1327)

Total  16.36 (220)
 14.94 (lS27)  13.01 (34)
 14.79 (2393) 
(Chi-square)  (0.599, 2 df, P=0.439)
 (1.347, 2 df, P=O.24)  (2.44, 2 df, P=O.l1S)
 (0.  , 2 df, P=0.936) 
(Phi)  (0.052)
 (0.027)  (0.84)  (0.002) 
be siz  99 bes  100-29 bes  30+ be  Total 
0-0  1S.75 (32)  13.24 (68)  17.50 (120)  16.36 (220) 
65-8  16.94 (242)  15.24 (676)  14.19 (90)  14.94 (1827) 
85+  15.28 (72)  13.74 (131)  11.19 (143)  13.01 (34) 
Total  16.76 (34)  14.86 (S75)
 14.16 (1172)  14.79 (2393) 
(Chi-square)  (0.210, 4 df, P=O.90)  (0.34, 4 df, P=O.84)
 (2140, 4 df, P=0.343)  (1.34 4 df, P=0.512) 
(Phi)  (0.025)  (0.020)  (0.43)  (0.24) 
loction  Metro  litan  Nonmetro  litan  Total 
0-0 
16.67 (168)  15.38 (52)  16.36 (220) 
65-8  15.41 (1402)  13.41 (425)  14.94 (lS27)

85+  11.86 (23)  15.45 (110)  1301 (34)

Total  15.06 (lS06)  13.97 (5S7)
 14.79 (2393) 
(Chi-square)  (2.355, 2 df, P=O.30)  (0.399, 2 df, P=0.S19)
 (1.340, 2 df, P=0.512) 
(Phil  (0.043)  (0.26)  (0.024) 
control  Non rofit  Profit  Government  Total 
0-0  16.7S (149)  17.86 (28)  13.95 (43)  16.36 (22) 
65-8  13.9S (1345)  16.41 (195)  1S.47 (287)  14.94 (lS27) 
85+  14.5S (24)  22.50 (40)  1.52 (66)  1301 (34) 
Total  14.3 (1734)  17.49 (263)
 15.15 (396)
 14.79 (2393) 
(Chi-square)  (0.S76, 4 df, P=0.645)  (0.S56, 4 df, P=0.652)
 (12.04, 4 df, P=0.OO2)
 (1.340, 4 df, P=0.512) 
(Phil  (0.022)  (0.057)  (0.174)  (0.024) 
teachin  sta tus  Teachin  Nonteachin  Total 
0-0  17.17 (99)  15.70 (121)  16.36 (220) 
65-8  16.09 (75S)  14.13 (1069)  14.94 (lS27) 
S5+  12.60 (127)  13.24 (219)  13.01 (34) 
Total  15.75 (984)  14.12 (140)
 14.79 (2393) 
(Chi-square)  (1.69, 2 df, P=0.557)  (0.389, 2 df, P=O.S23)
 (1.34 2 df, P=0.512) 
(Phil  (0.034)  (0.017  (0.24) 
Bed siz  loction Metro  litan  Nonmetro  litan  Total 
99  19.77 (86)  15.77 (26)  16.76 (34) 
100-299 bes  15.72 (59S) 13.00 (277)  14.86 (S75) 
30+ bes 
14.35 (1122)  10.00 (50)  14.16 (1172) 
Total  15.06 (180)  13.97 (5S7)
 14.79 (2393)

(Chi-square)  (2.136, 2 df, P=O.34)  (1.575, 2 df, P=0.455)
 (1.436, 2 df, P=O.48)

(Phil  (0.034)  (0.052)  (0.024) 
Bed siz  control  Non rofit  Profit  Government  Total 
99  19.75 (157)  23.21 (56)  10.53 (133)  16.76 (346) 
31000+-2 9b9e s  14.95 (5S2) 13.66 (161)  15.91 (132)  14.86 (S75) 
1307 (995)  23.91 (46)  19.08 (131)  14.16 (1172) 
Total  14.30 (1734)  17.49 (263)
 15.15 (396)
 14.79 (2393) 
(Chi-square)  (5.235, 4 df, P=0.73)  (4.219, 4 df, P=0.121)
 (3.84, 4 df, P=O.l46)
 (1.436, 4 df, P=O.48) 
(Phil  (0.055)  (0.127)  (0.09)  (0.024) 
Bed siz  teachin  status  Teachin  Nonteachin  Total 
99  25.00 (12)  16.47 (334)  16.76 (34) 
100-299 bes  17.17 (19S) 14.1S (677)  14.86 (S75) 
30+ bes 
15.25 (774)  12.06 (39S)  14.16 (1172) 
Total  15.75 (984)  14.12 (1409)
 14.79 (2393) 
(Chi-square)  (1.224, 2 df, P=0.542)  (2.911, 2 df, P=0.233)
 (1.436 2 df, P=O.48) 
(Phil  (0.035)  (0.045)  (0.024)  MLoteitorno pbyo lciotantnro 1l N4o.nprofit Profit  Government  Total 
33 (1403)  16.08 (199)  19.12 (20)  15.06 (180) 
Nonmetropolitan 14.
- Total 14.20 (331)  21.S7 (64)  10.94 (192)  13.97 (5S7) 
square)  30 (1734)  17.49 (263)  15.15 (396)
 14.79 (2393) 
.( C(hiP- hO (0(0..04, 2 dr, P=0.953) (1.127 2 dr, P=O.28)  (5.148, 2 dr, P=o.23)
 (0.419, 2 dr, P=O.SlS) 
001)  (0.065)  (0.114)  (0.013) 
Lotion by teachine: status Teachine:  Nonteachine:  Total 
Metropolitan 16.
08 (939)  13.96 (867)  15.06 (180) 
TNoonmteatrolpo li1tan5 S..S9 (45) 14.39 (542)  13.97 (5S7) 
square)  75 (984)  14.12 (140)  14.79 (2393) 
((CPhi- hO (0(1..674, 1 dr, P=o.l96) (0.052, 1 dr, P=0.S2O)  (0.419, 1 dr, P=0.51S) 
041)  (0.00)  (0.013 
PConrtroolf biy tte ac2hi2ne.: status Teachine:  Nonteachine:  Total 
Nonprofit 14.22 (27) 16.95 (23)  17.49 (263) 
Government  86 (86)
 13.74 (86)  14.30 (1734) 
Total 152.2.47 (S9)
 1303 (307)  15.15 (396) 
75 (984)
 14.12 (140)  14.79 (2393) 
((CPhi-shquOare () 0(4..399 2 dr, P=0.1l1) (1.961, 2 dr, P=0.375)  (1.S90, 2 dr, P=0.389) 
067)  (0.037)  (0.028)  -Appendix 9: Projected national CMI before recing by hospital demography, 1988 
CMI :t standard errr (n) 
Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
99 bes 
24  24 
Teaching  9102:t 0. (6)  no  9102:t 0. (6) 
Profit  Nonteaching  2243:t 0.1764 (20)  1.201 :t 0.1121 (33)  1.2148:t 0.954 (53)

Teaching & nonteaching  151S :t 0.146 (26)  201 :t 0.1121 (33)  lS39 :t 0.0893 (59)

00 
Teaching  1.0622 :t 0.1379 (2)  1.0774:t 0. (1)  1.0673 :t 0.798 (3) 
Nonprofit  Nonteaching  lS17:t 0.1162 (35)  1.06 :t 0.0538 (123)  1.09 :t 0.0491 (15S) 
Teaching & nonteaching  1.752:t 0.1101 (37)  067 :t 0.0533 (124)  091 :t 0.482 (161) 
00 
Teaching  5912:t 0. (1)  1.099 :t 0.3745 (3)  9705:t 0.2934 (4)

Government  Nonteaching  1.0317 :t 0.1165 (26)  1.0620 :t 0.043 (109)  1.0561 :t 0.04 (135)

Teaching & nonteaching  1.0154 :t 0.1132 (27)  1.0629 :t 0.047S (112)  0537:t 0.041 (139)

90  26 
Teaching  :t 0.1630 (9)  1.09 :t 0. (4)  9650 :t 0.1351 (13) 
All  Nonteaching  1.441 :t 0.75S (Sl)  0815 :t 0.34 (265)  092:t 0.0320 (34)

Teaching & nonteaching  1.205 :t 0.0703 (90)  0817 :t 0.034 (269)  0914 :t 0.0312 (359)

29 be 
100-
Teaching  1.2991 :t 0.241 (15)  no  1.291 :t 0.241 (15) 
Profit  Nonteaching  1.4367 :t 0.1194 (117)  4473 :t 0.124 (32)  1.4390 :t 0.093 (149)

Teaching & nonteaching  1.4210 :t 0.1091 (132)  1.4473 :t 0.124 (32)  4262 :t 0.0910 (164)

Teaching  1.3973 :t 0.079S (145)  1.46 :t 0.2593 (21)  4053:t 0.0767 (166) 
Nonprofit  Nonteaching  1.2974 :t 0.0520 (267)  1.20 :t 0.0654 (159)  2611 :t 0.047 (426) 
Teaching & nonteaching  3326 :t 0.0438 (412)  1.23 :t 0.0652 (180)  1.3015 :t 0.36 (592) 
Teaching  1.4597 :t 0.2500 (lS)  1.0029 :t 0.151S (3)  1.3944 :t 0.2171 (21) 
09 
Government  Nonteaching  2830 :t 0.1287 (46)  1.3385 :t 0. (70)  1.3165 :t 0.0769 (116) 
09 
Teaching & nonteaching  1.327 :t 0.1155 (64)  1.3247:t 0. (73)  1.328 :t 0.0728 (137) 
Teaching  1.3953 :t 0.0722 (17S)  1.4034 :t 0.2289 (24)  1.3963 :t 0.0690 (202) 
All  Nonteaching  1.3338 :t 0.047S (430)  1.2675 :t 0.0499 (261)  307:t 0.0352 (691) 
Teaching & nonteaching  351S :t 0.039S (60)  1.27S9 :t 0.0495 (285)  1.3285 :t 0.0314 (S93) 
30+ bes 
Teaching  1.0205 :t 0.1390 (S)  no case  0205 t 0.1390 (S) 
Profit  Nonteaching  1.0912 t 0.0952 (41)  no case  1.0912 t 0.0952 (41) 
Teaching & nonteaching  0797 t 0.0824 (49)  no  1.0797 t 0.0824 (49) 
04 
Teaching  1.4133 t 0. (703)  1.48 :t 0.1257 (15)  407S :t 0.041 (71S) 
Nonprofit  Nonteaching  1.3396 t 0.0544 (276)  2235 t 0.1889 (22)  1.3310 t 0.0522 (29S) 
Teaching & nonteaching  1.3925 t 0.0331 (979)  1.931 t 0.1221 (37)  1.3853 t 0.0322 (1016) 
Teaching  1.242 :t 0.1190 (65)  768 :t 0.2545 (2)  2338 t 0.1160 (67) 
Government  Nonteaching  1.23 :t 0.011880    1.38 :t 0.1889 (13)  2655 :t 0.1016 (67) 
Teaching & nonteaching  1.2426 t 0. (119)  3054 t 0.1740 (15)  1.2497 t 0.0768 (134) 
Teaching  1.3954 t 0.038 (776)  1.039:t 0.1167 (17) 3892:t 0.0377 (793) 
All  Nonteaching  1.2970 t 0.0453 (371)  28 t 0.136 (35)  1.296 t 0.0430 (40) 
Teaching & nonteaching  3636 t 0.029S (1147)  1.2255 t 0.097 (52)  1.3576 t 0.0289 (1199) 
All hos itals 
Teaching  1.41S t 0.1391 (29)  no case  1.41S t 0.1391 (29) 
Profit  Nonteaching  1.3332 :t 0.083 (17S) 1.326 t 0.08 (65)  1.3314 t 0.0657 (243) 
Teaching & nonteaching  1.30 t 0.0751 (207)  1.326 t 0.08 (65)  1.3112 t 0.065 (272) 
Teaching  1.40S t 0.036 (SSO)  3237 t 0.1561 (37)  1.4062 t 0.0355 (887) 
Nonprofit  Nonteaching  1.3105 t 0.036 (57S)  1.469 t 0.0428 (304)  1.2541 t 0.0279 (882) 
Teaching & nonteaching  1.3696 t 0.0261 (1428)  1.661 :t 0.0417 (341)  1.330 :t 0.0226 (1769) 
Teaching  1.2857 t 0.1065 (84)  9795 :t 0.1489 (S)  1.2590 t 0.0984 (92) 
Government  Nonteaching  1.110 t 0.0730 (126)  1.849 t 0.0471 (192)  1.952 t 0.045 (31S) 
Teaching & nonteaching  1.2409 t 0.0610 (210)  1.766 t 0.0456 (20)  205 t 0.0383 (410) 
Teaching  1.390 t 0.0337 (963)  1.2625 t 0.1320 (45)  1.3851 :t 0.0327 (l00S) 
All  Nonteaching  1.30 t 0.030 (882)  1.807 t 0.0299 (561)  1.2542 t 0.0222 (1443) 
Teaching & nonteaching  1.3479 t 0.0230 (1845)  1.86 t 0.0293 (60)  1.30 t 0.0188 (2451)  Appendix 10: Projected national CMI before reing by patient demography, 1988 
CMI:I standard errr (n)

Male  Female  Male & female

0-6  ears

White  3911 :I 0.1076 (113)  1.2161 :I 0.0972 (68)  1.3253:1 0.0765 (lSl)
Black  1.4755 :I 0.2295 (21)  9S99 :I 0.07S1 (lS)  1.2514 :I 0.1331 (39)
Other  S347 :I 0.1370 (S)  1.5011 :I 0.5568 (3)  1.0165 :I 0.lS7S (11)
Unknow  no case  7493:1 0.00 (1)  7493:1 0.00 (1)
All race  1.3722 :I 0.0928 (142)  1.751 :I 0.0774 (90)  1.295S :I 0.06 (232) 
65-74  ears 
White  1.4345 :I 0.0526 (45S)  1.3235 :I 0.0455 (46)  1.3786 :I 0.034 (922)
Black  5131 :I 0.1795 (30)  1.543 :I 0.1014 (38)  1.2567 :I 0.1005 (68)
Other  1.4375:1 0.1785 (5)  22316 :I 0.5628 (S)  922 :I 0.36 (13)
Unknow  1.3814 :I 0.2750 (3)  S535 :I 0.00 (1)  1.2494 :I 0.2350 (4)
All race  1.4389 :I 0.049S (496)  1.3168:1 0.0432 (511)  1.3769 :I 0.329 (1007) 
75-8  yea 
Whte  1.2776 :I 0.0432 (328)  1.2631 :I 0.0434 (456)  2692 :I 0.0310 (784)
Black  1.S33 :I 0.1373 (26)  9396 :I 0.689 (27)  1.0591 :I 0.0771 (53)
Other  1.5S5 :I 0.0675 (5)  1.3692 :I 0.370 (2)  1.21S7 :I 0.090 (7)
Unknow  7977:1 0.1495 (4)  262:1 0.5112 (6)  1.0752 :I 0.305 (10) 
Al race  1.2639 :I 0.043 (363)  1.2457:1 0.0410 (491)  1.2535 :I 0.0291 (S54) 
S5+  ears 
White  3333 :I 0.029034  (S2)  1.2326 :I 0.0425 (23)  1.2586 :I 0.0396 (31S)
Black  1.51S :I 0. (S)  1.477:1 0.1759 (20)  1.489:1 0.1370 (28)
Other  1802 :I 0.205074  (2)  2104 :I 0.lS74 (2)  1953:1 0.1302 (4)
Unknow  1.0222:1 0. (1)  1.4490 :I 0.369 (7)  1.3956 :I 0.3239 (S) 
Al race  1.110 :I 0.0843 (93)  1.2317:1 0.0411 (265)  1.2523 :I 0.0374 (35S) 
AII al!es 
White  1.36 :I 0.003920  (9S1)  2775 :I 0.0256 (1224)  1.3180 :I 0.0201 (2205)
Black  1.369 :I 0. (S5)  1.0311 :I 0.0551 (103)  1.S38 :I 0.0544 (188)
Other  1.00 :I O.OS99 (20)  l.S343 :I 0.3289 (15)  1.4152 :I 0.159S (35)
Unknow  046 :I 0.1527 (S)  1.2871 :I 0.262 (15)  1.2028 :I 0.1769 (23)
All race  1.3613 :I 0.029S (1094)  1.2651 :I 0.0240 (1357)  30 :I 0.0188 (2451)  Appendix 11: Projected national CMI after recing by hospital demography, 1988 
CMI t standard errr (n) 
Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
99 
Teaching  9536 t 0.2322 (6)  no  9536 t 0.2322 (6) 
Profit  Nonteaching  1.2292 t 0.1749 (20)  1.233 t 0.126 (33)  1.2323 t 0.101S (53) 
Teaching & nonteaching  1656 t 0.144 (26)  1.233 t 0.126 (33)  1.20 t 0.945 (59) 
00 
Teaching  1.0630 t 0.1371 (2)  1.0774 t 0. (1)  1.067S t 0.0793 (3)
Nonprofit  Nonteaching  1.402 t 0.1156 (35)  1.06 t 0.0510 (123)  1.0827 t 0.0471 (15S)
Teaching & nonteaching  1.36 t 0.1095 (37)  1.06 t 0.0506 (124)  1.0824 t 0.043 (161) 
00 
Teaching  5912 t 0. (1)  1.222 t 0.399 (3)  9S94 t 0.3123 (4) 
Goernment  Nonteaching  9450 t 0.0859 (26)  1.742 t 0.0522 (109)  1.0493 t 0.0454 (135) 
04 
Teaching & nonteaching  9319 t 0.0836 (27)  1.0755 t 0.0516 (112)  0476 t 0. (139) 
Teaching  9376 t 0.1585 (9)  1.110 t 0.2829 (4)  9910 t 0.1352 (13) 
Nonteaching  1.095 t 0.07167  (Sl)  1.905 t 0.0356 (265)  1.09 t 0.0320 (34) 
Teaching & nonteaching  1.0833 t 0. (90)  1.09 t 0.353 (269)  1.089 t 0.0312 (359) 
100-299 bes 
Teaching  1.3773 t 0.2935 (15)  no  3773 t 0.2935 (15) 
Profit  Nonteaching  1.4339 t 0.l1S5 (117)  4354 t 0.1410 (32)  1.4342 t 0.0976 (149) 
Teaching & nonteaching  1.4274 t 0.109 (132)  1.4354 t 0.1410 (32)  1.4290 t 0.09 (164) 
Nonprofit  TNeoanctheiancgh ing  11..3329194  tt  00..572711  ((216475))

 1.2450416  tt  00..0256939 ( (12519) )  11..42076S13  tt  00..007446  ((146266))
Teaching & nonteaching  347 t 0.0433 (412)  231 t 0.063 (180)  1.3141 t 0.036 (592) 
24 
Teaching  1.5520 t 0. (lS)  980 t 0.017826  (3)  1.4704 t 0.2140 (21) 
Government  Nonteaching  2494 t 0.1211 (46)  2877 t 0. (70)  2725 t 0.0707 (116) 
Teaching & nonteaching  1.3345 t 0.1111 (64)  1.2751 t 0.0837 (73)  1.328 t 0.062 (137) 
Teaching  1.4127 t 0.0714 (17S)  1.3954 t 0.202497  (24)  1.4106 t 0.06 (202) 
All  Nonteaching  1.343 t 0.0474 (430)  2561 t 0. (261)  1.110 t 0.034 (691) 
04 
Teaching & nonteaching  363 t 0.395 (60)  1.267S t 0. (285)  3335 t 0.311 (S93) 
30+ bes 
Teaching  9125 t 0.1588 (S)  no case  9125 t 0.1588 (S) 
Profit  Nonteaching  1.798 t 0.109 (41)  no case  1.798 to.109 (41) 
Teaching & nonteaching  1362 t 0.0955 (49)  no  1362 t 0.0955 (49) 
Teaching  1.402 t 0.399 (703)
 1499 t 0.1255 (15)  40 t 0.0392 (71S) 
Nonprofit  Nonteaching  1.3516 t 0.0550 (276)  2490 t 0.lS70 (22)  34 t 0.0527 (29S)
Teaching & nonteaching  390 t 0.325 (979)  20 t 0.1211 (37)  1.3842 t 0.317 (1016) 
Teaching  1.2723 t 0.1232 (65)  768 t 0.2545 (2)  1.2573 t 0.120 (67) 
Government  Nonteaching  1.205 t 0.l1S9 (54)  4267 t 0.188 (13)  2517 t 0.1026 (67) 
Teaching & nonteaching  2438 t 0.0859 (119)  3389 t 0.1747 (15)  2545 t 0.786 (134) 
Teaching  1.3899 t 0.0376 (776)  1.050 t 0.1166 (17)  1.3838 t 0.0369 (793) 
All  Nonteaching  1.3120 t 0.0460 (371)  3150 t 0.135S (35)  1.3122 t 0.0436 (40)
Teaching & nonteaching  1.367 t 0.0295 (1147)  243 t 0.093 (52)  1.3595 t 0.0285 (1199) 
All hos itals 
Teaching  1.614 t 0.1667 (29)  no  1.614 t 0.1667 (29) 
Profit  Nonteaching  1.3524 t 0.083 (17S)  3333 t 0.0947 (65)  1.3473 t 0.06 (243) 
Teaching & nonteaching  1.3256 t 0.762 (207)
 1.3333 t 0.0947 (65)  3274 t 0.0621 (272) 
Teaching  1.401 t 0.355 (S50)
 1.320 t 0.1563 (37)  1.407 t 0.34 (887) 
Nonprofit  Nonteaching  1.324 t 0.363 (57S)
 1.527 t 0.041S (30)  1.2655 t 0.279 (882) 
Teaching & nonteaching  3720 t 0.257 (1428)
 1709 t 0.0409 (341)  3333 t 0.223 (1769) 
Teaching  3241 t 0.1091 (84)  980 t 0.1591 (S)  1.2943 t 0.100 (92) 
Government  Nonteaching  1695 t 0.007600  (126)  1.759 t 0.00445S  (192)  1734 t 0.0391 (31S) 
Teaching & nonteaching  1.2314 t 0. (210)  1.681 t 0. (200)  1.205 t 0.037S (410) 
Teaching  1.3899 t 0.331 (963)  1.26 t 0.1324 (45)  1.381 t 0.0322 (l00S) 
All  Nonteaching  1.3082 t 0.30 (882)  1.S15 t 0.296 (561)  1.2590 t 0.0222 (1443) 
Teaching & nonteaching  1.508 t 0.227 (1845)
 1.S74 t 0.0291 (60)  1.3104 t O.Ql86 (2451)  Appendix 12: Projected national CMI after recing by patient demography, 1988 
CMI t standard eITr (n) 
Male  Female  Male & female

0-6  ears

White  1.4053 t 0.1070 (113)  2675 t 0.1083 (68)  3535 t 0.07S2 (lSl) 
Black  1.4144 t 0.2245 (21)  1.00 t 0.0796 (lS)  223 t 0.1293 (39) 
Other  1.342 t 0.243 (S)  1.6164 t 0.4901 (3)  2657 t 0.2216 (11)
Unknow  no case  7493 t 0.00 (1)  7493 t 0.00 (1) 
Al race  1.3914 t 0.091 (142)  220 t 0.0855 (90)  3249 t 0.0655 (232) 
65-74  ears 
White  1.403 t 0.0508 (45S)  1.3233 t 0.04 (46)  36 t 0.0337 (922) 
Black  1.4652 t 0.1741 (30)  1.0727 t O.09S (38)  1.2459 t 0.0971 (68) 
Other  1.4375 t 0.1785 (5)  2121 t 0.5697 (S)  1.9142 t 0.3639 (13)
00 
Unknow  1.3814 t 0.2750 (3)  S535 t 0. (1)  2494 t 0.2350 (4)
All race  1.4101 t 0.041 (496)  1.3177 t 0.0422 (511)  3632 t 0.0319 (1007) 
75-8  ears  04 
White  277S t 0. (328)  1.2653 t 0.0428 (456)  2705 t 0.0310 (784) 
Black  228 t 0.140 (26)  9794 t 0.0837 (27  1017 t 0.0822 (53) 
Other  1.055 t 0.1100 (5)  1.392 t 0.370 (2)  1.80 t 0.1177 (7)
Unknow  7977 t 0.1495 (4)  262 t 0.5112 (6)  1.0752 t 0.35 (10)
All race  26 t 0.0414 (363)  1.2500 t 0.045 (491)  2570 t 0.0292 (S54) 
S5+  vea 
Whte  1.4226 t 0.1010 (S2)  1.241S t 0.0436 (23)  28 t 0.0417 (31S) 
Black  2314 t 0.196 (S)  1.1191 t 0.1788 (20)  1.512 t 0.1379 (28)
Other  1.802 t 0.2574 (2)  3409 t 0.0569 (2)  1.265 t 0.1172 (4)
00 
Unknow  1.0222 t 0.09 (1)  1.4573 t 0.362 (7)  1.4029 t 0.3201 (S)
All race  1.396 t 0. (93)  1.2390 t 0.0421 (265)  2799 t 0.0392 (35S) 
All ae:es

White  36 t 0.0317 (9S1)  1.2829 t 0.0254 (1224)  1.3192 t 0.0199 (2205) 
Black  1.35S3 t 0.0943 (S5)  1.047 t 0.0563 (103)  1.865 t 0.0537 (188) 
Other  1.2075 t 0.1127 (20)  1.86 t 0.324 (15)  4890 t 0.1603 (35) 
Unknown  1.04 t 0.1527 (S)  1.2910 t 0.2591 (15)  1.2053 t 0.1762 (23)
All race  35S9 t 0.0294 (1094)  1.2713 t 0.023 (1357)  1.3104 t 0.0186 (2451)  Appendix 13: Mean CMI change by hospital demogrphy, 1988 
CMI change :t standard errr (n)  Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan

99 bes 
Teaching  004033 :t 0.0433 (6) no  09  0433:t 0.0433 (6)

Profit  Nonteaching  :t 0.0145 (20)  0251 :t 0. (33)  0175 :t 0.057S (53)

Teaching & nonteaching  0137 :t 0.0148 (26)  0251 :t 0.099 (33)  0201 :t 0.0520 (59)

00  00  00  00 
Teaching  :t 0. (2)  :t 0. (1)  0.005 :t 0.005 (3)

Nonprofit  Nonteaching  -0.0415 :t 0.0538 (35)  0017 :t 0.020 (123)  -O.007S :t 0.195 (15S)

Teaching & nonteaching  -0.0392 :t 0.0509 (37)  0017 :t 0.019S (124)  -0.0077 t 0.0192 (161)

00  00 
Teaching  :t 0. (1)  0252 :t 0.0252 (3)  01S9:t 0.01S9 (4)

Government  Nonteaching  -0.087 :t 0.065 (26)  0.122 :t 0.0177 (109)  -0.00 :t 0.0186 (135)

Teaching & nonteaching  -0.0835 :t 0.05S3 (27)  0.125 :t 0.0172 (112)  -0.00 :t 0.0180 (139)

Teaching  029 :t 0.028 (9)  0.lS9 :t 0.01S9 (4)  0259 :t 0.0203 (13)

Nonteaching  -0.045 :t 0.030 (Sl)  009:t 0.0164 (265)  -0.0035 :t 0.0144 (34)

Teaching & nonteaching  -0.0372 :t 0.276 (90)  001 :t 0.0161 (269)  -0.0025 :t 0.0139 (359)

100-299 bes 
Teaching  07S2 :t 0.1457 (15)  no 
 07S2 :t 0.1457 (15)

Profit  TNeoanctheiancgh i&ng n onteaching  -00.00027 : t: t0 0.0.0226311 ( 1(13127) ) --00..00111199  ::tt  00..0055SS99  ((3322))

 -00.0007  ::tt  00..00223290 ( 1(16449) )

Teaching  0017:t 0.0341 (145)  -0.0059 :t 0.0059 (21)  0.007 :t 0.029S (166)

Nonprofit  Nonteaching  0239 :t 0.0245 (267)  001 :t 0.0194 (159)  0172 :t 0.0170 (426)

Teaching & nonteaching  0160 :t 0.0199 (412) .  007 :t 0.0172 (180)  0126 :t 0.0148 (592)

09 
Teaching  :t 0.0915 (lS)  -0.0222 :t 0.0222 (3)  0759 :t 0.0786 (21) 
Government  Nonteaching  -0.0335 :t 0.0373 (46)  -0.0508 :t 0.0451 (70)  -0.0439 :t 0.030 (116) 
Teaching & nonteaching  OOlS :t 0.0374 (64)  -0.0496 :t 0.0433 (73)  -0.0256 :t 0.0289 (137) 
00 
Teaching  0173:t 0.316 (17S)
 -0. :t 0.005S (24)  0143 :t 0.027S (202) 
Nonteaching  0105 :t 0.0169 (430)  -0.0113 :t 0.0184 (261)  0022 :t 0.0126 (691) 
Teaching & nonteaching  0124 :t 0.0151 (60)  -0.0110 :t 0.0168 (285)  009 :t 0.0116 (S93) 
30+ bes 
Profit  TNeoanctheiancgh ing  -00.1808  ::tt  00.0.765221  ((4S1))  nnoo   -00.1808  ::tt  00.0.765221  ((4S1))

Teaching & nonteaching  0565 :t 0.541 (49)  no  0565 :t 0.0541 (49)

Teaching  -0.0071 :t 0.0157 (703)  0013 :t 0.0013 (15)  -0.009 :t 0.0154 (71S) 
Nonprofit  Nonteaching  0120 :t 0.015S (276)  0254 :t 0.020 (22)  0130 :t 0.0147 (29S) 
Teaching & nonteaching  -0.0017 :t 0.0121 (979)  0156 :t 0.0123 (37)  -0.0011 :t 0.0117 (1016) 
00  00 
Teaching  0241 :t 0.030 (65)  :t 0. (2)  023 :t 0.030 (67) 
Government  Nonteaching  -0.026 :t 0.0560 (54)  0.38 :t 0.038 (13)  -0.0138 :t 0.045S (67)
Teaching & nonteaching  0012 :t 0.305 (119)  0334 :t 0.0334 (15)  00 :t 0.0273 (134) 
Teaching  -0.0055 :t 0.0145 (776)  0011 :t 0.0011 (17)  -0.0054 :t 0.0142 (793) 
All  Nonteaching  0149:t 0.0159 (371)  0303 :t 0.0190 (35)  0162:t 0.0146 (406) 
Teaching & nonteaching  0010 :t 0.0110 (1147)  020 :t 0.0129 (52)  0019 :t 0.0106 (1199) 
All hos itals 
Teaching  . 0.0196 :t 0.786 (29)  no00  0196 :t 0.0786 (29)

Profit  Nonteaching  0191 :t 0.0210 (17S)  00 :t 0.0550 (65) 015S :t 0.0212 (243)

Teaching & nonteaching  0192 :t 0.0211 (207)  :t 0.0550 (65)  0162 :t 0.0207 (272)

Teaching  -O.0056:t 0.0142 (S50)  -0.0028 :t 0.0034 (37)  -0.0055 :t 0.0136 (887) 
Nonprofit  Nonteaching  001042  :t 0.0140 (57S) 000057  :t 0.0130 (30) 0113 :t 0.0102 (882) 
Teaching & nonteaching  :t 0.0102 (1428)  :t 0.0116 (341)  0028 :t 0.OOS5 (1769) 
Teaching  038 :t 0.030 (84)  0011 :t 0.0134 (S)  0352 :t 0.0281 (92) 
Government  TNeoanctheiancgh i&ng n onteaching  --00..0040154  ::tt  00..00232001  ((211206))   --00..000095  ::tt  00..0011S975  ((12902))   --O0..00201S  ::tt  00..00116475  ((3411S0))  
Teaching  -0.0010 :t 0.0130 (963)  -00.00021  :t 0.0036 (45) -0.0010 :t 0.0125 (l00S) 
Nonteaching  0073 :t 0.001010  (882)  00 :t 0.0116 (561) 007 :t 0.001 (1443)

Teaching & nonteaching  0029 :t 0. (1845)  :t 0.0107 (60)  0023 :t 0.0070 (2451)
 Appendix 14: Mean CMI change by patient demography, 1988 
CMI change :I standard errr (n)  Male  Female  Male & female 
0-6  vea 
White  0142 :I 0.0338 (113)  0514 :I 0.034 (68)  0281 :I 0.0247 (lSl) 
Black  -0.0611 :I 0.0595 (21)  0107 :I 0.0107 (lS)  -0.0279 :I 0.325 (39)
Other  2995 :I 0.2172 (S)  1153 :I 0.1153 (3)  2492 :I 0.1594 (11)
Unknow  no case  0040  :I 0.00 (1)  00 :I 0.00 (1)
All race  0.191 :I 0.0311 (142)  :I 0.0263 (90)  0291 :I 0.215 (232) 
65-74  ears 
White  -0.0281 :I 0.0166 (45S)  -0.0001 :I 0.0192 (46)  -0.0140 :I 0.0127 (922)

Black  -00.0407 9:1 00.9019  (30)  0184 :I 0.434 (38)  -0.0108 :I 0.0470 (68)

OUtnhkenr ow  00 ::II  00..00 ((35))   -000.010094  ::I1 0 0.0.01094 ( (1S) )  -00.0101 9: I:I 0 0.0.0101 9( (41)3
 )

All race  -0.028 :I 0.0163 (496)  :I 0.0177 (511)  -0.0137 :I 0.0120 (1007)

75-8  ears 
White  0.001 :I 0.0179 (328)  0022 :I 0.0147 (456)  0013 :I 0.0114 (784) 
Black  0453 :I 0.0775 (26)  0.0390S  :I 0.07907  (27)  0425 :I 0.0551 (53)
OUtnhkenr ow  -00.0503 0: I:I 0 0.0.0503 0( (45))   00 ::II  00..00 ((62))   -00.0037:19  :0I 0.0.0307 9( (170))
All race  0026 :I 0.0171 (363)  002:1 0.0143 (491)  0035 :I 0.0110 (S54) 
S5+  ears

White  0892 :I 0.0535 (S2)  001 :I 0.0156 (23)  029S :I 0.0180 (31S)

Black  0.07905  :I 0.05308  (S)  -0.028 :I 0.0165 (20)  0022 :I 0.020 (28)

Other  00 :I 0.00 (2)  1305 :I 0.1305 (2)  0652:1 0.0652 (4)

Unknow  :I 0. (1)  003 :I 0.335 (7)  0072 :I 0.0291 (S)

All race  0855:1 0.0474 (93)  0072 :I 0.0140 (265)  0.275 :I 0.0161 (35S)

All ae:es

White  -0.0039 :I 0.0115 (9S1)  0053 :I 0.007 (1224)  0012 :I 0.0074 (2205)
Black  -0.0106 :I 0.0429 (S5)  0135 :I 0.0263 (103)  0026 :I 0.0241 (188)
Other  010065  :I 0.00901S  (20)  030 :I 0.0307 (15)  0.737 :I 0.0538 (35)
AUlnl krancoew   -0.0024: I:I  00..0109( (S1)0 94)  0000328  ::II  00..001050  ((11355) 7)  00002253  ::II  00..0000770  ((2234)51)  Appendix 15: Mean reimbursment change by hospital demography, 1988 
$ :t standard errr (n)  Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
99 bes 
Teaching  135.16 :t 135.16 (6)  no  135.16 :t 135.16 (6) 
Profit  Nonteaching  15.16 :t 45.22 (20)  66.38 :t 245.17 (33)  47.06 :t 152.72 (53) 
Teaching & nonteaching  42.86 :t 46.27 (26)  66.38 :t 245.17 (33)  56.02 :t 137.68 (59) 
Teaching  2.49 :t 2.49 (2)  00 :t 0.00 (1)  66 :t 1.66 (3) 
Nonprofit  Nonteaching  129.47:t 167.91 (35)  53:t 52.79 (123)
 25.15 :t 55.30 (15S) 
Teaching & nonteaching  122.34 :t 15S.79 (37)  49 :t 52.37 (124)  24.65 :t 54.27 (161) 
Teaching  00 :t 0.00 (1)  66.62 :t 66.62 (3)  49.97 :t 49.97 (4) 
Government  Nonteaching  270.5S :t 188.75 (26)  32.26:t 46.67 (109)  26.06 :t 52.95 (135)

Teaching & nonteaching  26.56 :t 1Sl.90 (27)  33.18 :t 45.44 (112)  23.S7 :t 51.45 (139)

Teaching  90.66 :t 90.04 (9)  49.97 :t 49.97 (4)  7S.14 :t 62.95 (13) 
All  Nonteaching  139.05:t 94.94 (Sl)  23.64 :t 43.28 (265)  14.44 :t 40.01 (34) 
Teaching & nonteaching  116.08 :t 86.13 (90)  24.03 :t 42.64 (269)  11.09 :t 38.63 (359) 
100-29 bes 
Teaching  243.S2 :t 454.56 (15)  no  243.S2 :t 454.56 (15) 
Profit  Nonteaching  -8.66 :t 72.29 (117)  31.56 :t 155.51 (32)  135S:t 65.61 (149)

Teaching & nonteaching  20.02 :t S1.61 (132)  31.56 :t 155.51 (32)  95 :t 72.16 (164) 
Teaching  5.3 :t 106.40 (145)  15.74 :t 15.74 (21)  67 :t 9292 (166) 
Nonprofit  Nonteaching  74.55 :t 76.64 (267)  16.11 :t 51.38 (159)  52.74:t 51.69 (426) 
Teaching & nonteaching  50.19 :t 62.14 (412)  12.39 :t 45.41 (180)  38.70:t 45.38 (592) 
Government  TNeoanctheiancgh ing  218074.8.644 : t: t2 18156.3.361 ( (l4S6))   51384.2.0 8:t  :5t S1.1692.1 (S3 )( 70)  21322.3.441 : t: t2 S455..111S  ((12116)) 

Teaching & nonteaching  73 :t 116.70 (64)  13O.9S :t 114.28 (73)  -67.11 :t S1.64 (137)

Teaching  54.00 :t 9S.64 (17S)  21.0 :t 15.32 (24)  45.08 :t 86.93 (202) 
All  Nonteaching  32.74:t 52.97 (430)  30.01 :t 48.56 (261)  03 :t 37.71 (691) 
30+ bes  Teaching & nonteaching  38.96 :t 47.26 (60)  29.26 :t 44.48 (285)  17.19:t 35.17 (S93) 
Teaching  336.74:t 23.56 (S)  no case
 336.74 :t 23.56 (S) 
Profit  Nonteaching  276.34 :t 193.68 (41)  no case
 276.34 :t 193.68 (41) 
Teaching & nonteaching  176.24 :t 168.93 (49)  no  176.24:t 168.93 (49) 
Nonprofit  TNeoanctheiancgh ing  3272.6.332 : t: t4 499.4.18 2( (277063) )  675.119 : t: t3 5.541.4 (61 5(2) 2)  3291.S.71S : t: t4 458.9.190  ((2791SS))  
Teaching & nonteaching  5.42 :t 37.93 (979)  41.37:t 32.52 (37)  71 :t 36.56 (1016) 
Teaching  75.38 :t 96.50 (65)  00 :t 0.00 (2)  73.13 :t 93.61 (67) 
Government  Nonteaching  -82.48 :t 174.91 (54)  101.86 :t 101.86 (13)  -4.71 :t 142.29 (67) 
Teaching & nonteaching  74 :t 95.11 (119)  88.28 :t 88.28 (15)  13.21 :t S5.00 (134) 
Teaching  17.38:t 45.30 (776)  10 :t 3.10 (17)  16.94 :t 44.33 (793) 
All  Nonteaching  46.53 :t 49.62 (371)  80.07 :t 50.20 (35)  49.42:t 45.54 (40)

Teaching & nonteaching 
29:t 34.59 (1147)
 54.91 :t 34.02 (52)  5.52 :t 33.12 (1199) 
All hos itals 
Teaching  61.S :t 245.20 (29)  no case
 61.S :t 245.20 (29) 
Profit  Nonteaching  59.65 :t 65.64 (17S)  1S.16 :t 145.13 (65)
 48.56 :t 61.64 (243) 
Teaching & nonteaching  59.S7 :t 65.79 (207)  1S.16 :t 145.13 (65)
 49.90 :t 60.77 (272) 
Nonprofit  TNeoanctheiancgh ing  4147.5.574::tt  4434..7437  ((5875S0))   15.5112  ::tt  93.40.84 9(3 (73) 0)  3147.4.122 ::tt  3412..0612  (8(88827))  
Teaching & nonteaching  7.59 :t 31.84 (1428)  12.67 :t 30.76 (341)  57 :t 26.38 (1769) 
Teaching  120.01 :t 96.04 (84)  99 :t 35.56 (S)  109.84 :t S7.76 (92) 
Government  Nonteaching  129.39 :t 94.07 (126)  23.66 :t 51.0 (192)  -65.55 :t 48.54 (31S) 
Teaching & nonteaching  29.62 :t 68.64 (210)  22.60 :t 49.45 (20)  26.20 :t 42.59 (410) 
Teaching  17 :t 40.S0 (963)  64 :t 9.57 (45)  28 :t 38.9S (100) 
All  TNeoanctheiancgh i&ng n onteaching  222.27 6: t: t2 634.8.83 4( 1(884852))   1.2601  ::tt  3280..6326  ((56601))   143.746 : t: t2 214.4.112 ( 2(4154143) )  Appendix 16: Mean reimbursment change by patient demography, 1988 
$ t standard errr (n)  Male  Female  Male & female 
0-6  vea

White  40.71 t 104.51 (113)  155.88 :I 107.13 (68)  83.98 t 76.5S (lSl)

Black  190.50 t 185.56 (21)  33.43 t 33.43 (lS)  -87.5 :I 101.57 (39)

Other  S91.56 t 667.32 (S)  30.13 :I 30.13 (3)  731.35 t 48.46 (11)

Unknown  no case  00 t 0.00 (1)  00 t 0.00 (1)

All race  54.45 :I 96.00 (142)  134.60 t S1.73 (90)  S5.54 t 66.69 (232)

65-74  vea 
White  -8.72 t 50.63 (45S)  02:1 59.08 (46)  -4.61 t 38.94 (922) 
Black  149.44 t 28.54 (30)  57.57 t 135.40 (38)  33.75 t 146.61 (68)
Other  00 t 0.00 (5)  -6.68 t 60.68 (S)  37.3 t 37.3 (13)
Unknow  00 t 0.00 (3)  00 t 0.00 (1)  00 t 0.00 (4)
All race  -87.26 t 49.77 (496)  1.23 t 54.57 (511)  -43.60 t 36.99 (1007) 
75-8  vea 
White  1.27 t 55.41 (328)  12.31 t 44.47 (456)  69 t 34.71 (784) 
Black  141.35 t 241.91 (26)  121.3 t 24.39 (27)  131.7 t 171.S1 (53)
Other  139.91 t 139.91 (5)  00 :I 0.00 (2)  99.94 :I 99.94 (7)
Unknow  00 :I 0.00 (4)  00:1 0.00 (6)  00 t 0.00 (10) 
Al race  35 :I 52.94 (363)  1S.11 :I 43.44 (491)  14.38 t 33.60 (S54) 
S5+  vea

White  272.41 t 159.53 (S2)  26.74 t 47.21 (23)  90.09 t 54.21 (31S)

Black  247.99 t 167.79 (S)  -89.17 t 51.65 (20)  16 t 65.46 (28)

Other  00 t 0.00 (2)  344.12 t 344.12 (2)  172.06 t 172.06 (4)

Unknown  00 t 0.00 (1)  34.32 t 99.43 (7)  30.03 t 86.22 (S)

All race  261.53 t 141.30 (93)  20.59 t 42.39 (265)  S3.1S t 48.49 (35S) 
All al!es

White  11.66 t 35.07 (9S1)  16.50 t 29.S9 (1224)  96 t 22.77 (2205)

Black  33.23 :I 133.S2 (S5)  41.5S t S2.19 (103)  75 t 75.25 (188)

Other  321.64 t 279.65 (20)  74.34 t S3.35 (15)  215.65 t 163.21 (35)

Unknown  00 t 0.00 (S)  16.01 t 44.70 (15)  10.44 t 28.84 (23)
All race  16 t 33.50 (1094)  19.03 t 27.69 (1357)  34 t 21.41 (2451)  Appendix 17: Number of bills by hospital demography, 1988 
Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
- 1-99 bes 
Teaching  S76  691  10,567

Profit  Nonteaching  977  175 241

Teaching & nonteaching  853  92,955  1S5

Teaching  037  421

Nonprofit  Nonteaching  174  439 549  614,477

Teaching & nonteaching  196,312  586  64,S9S

Teaching  569  419  10,988

Government  Nonteaching  337  405 219  491 556

Teaching & nonteaching  411 638  502,544

Teaching  S29  147  976

All  Nonteaching  345,242  032  281 274

Teaching & nonteaching  38,071  953 179  333,250

100-299 bes 
Teaching  50,  53,594

Profit  Nonteaching  450,101  116,651  566 752

Teaching & nonteaching  501,049  119 297  620

Teaching  593,S74  74,  667 883

Nonprofit  Nonteaching  692  590 S59  639,551

Teaching & nonteaching  642 566  307,434

Teaching  52,050  11,592  642

Government  Nonteaching  211 194  251 962  463 156

Teaching & nonteaching  263  263 554  526,79S

Teaching  696 S72  247  7S5 119

All  Nonteaching  709,9S7  959 472  669,459

Teaching & nonteaching  S59  047 719  454 57S

30+ bes 
Teaching  320  320

Profit  Nonteaching  176 753  695  177

Teaching & nonteaching  216 073  695  216 768

Teaching  751 312  639  S3O,951 
Nonprofit  Nonteaching  984,754  301  075 055 
Teaching & nonteaching  736  169,940 
Teaching  345 560  23,249  36, 
Government  Nonteaching  1S5,51S  41,426  226,944 
Teaching & nonteaching  531 07S  675  595 753 
Teaching  136 192  102,  239,

All  Nonteaching  347,025  132,422  479 447

Teaching & nonteaching  483 217  235,310  71S 527

All hos itals 
Teaching  144  337  103 481

Profit  Nonteaching  710 S31  610  919 441

Teaching & nonteaching  975  212 947  022 922

Teaching  570  162 685  529,255

Nonprofit  Nonteaching  374  120 709  329 083

Teaching & nonteaching  574 944  283 394  S5S,338

Teaching  402,179  443,439

Government  Nonteaching  483 049  69S 607  lSl 656

Teaching & nonteaching  885 228  739 867  625,095

Teaching  867 S93  282  076,175 
All  Nonteaching  402,254  027,  430 180 
Teaching & nonteaching  270 147  506 355 
Ii "  Appendix 1S: Number of bils by patient demography, 1988 
Male  Female  Male & female 
. 0-6  ears 
White  433,869  341  720,210 
Black  765  170 173 
Other  413  761  32,174 
Unknow  621  472  093 
All race  555,  9S2  940,650 
65-74  ears

White  067  736 299  424,

Black  142 841  170 281  313 122

Other  32,047  889

Unknow  59,395  474  125 869

All race  922 350  943  932,293

75-8  ears

White  017  303  S94 32O

Black  100 353  137 S71  23,224

Other  111  117 
Unknow  761  530  291 
All race  1,394 242  869 710  263 952 
S5 +  ears 
White  383 775  838 975  750 
Black  695  105,685 
Other  338  S15  13,153 
Unknow  l88  690  S7S 
All race  431  937 470  369 
All ae:es

White  739,728  521 91S  261, 
Black  369,654  457 550  S27 
Other  73,471  150 
Unknown  117 965  149,166  267 
All race  256  202 105  506,361 
, This total includes six bils not in the prevous table beus 
they could not be classified by hospital control.  Appendix 19: Projected reimbursment effect by hospital demography, 1988 
$1,00 t standard errr  Metropolitan  Nonmetropolitan  Metropolitan & nonmetropolitan 
99 
Teaching  20 t 1
 no 
 428 t 1,428

Profit  Nonteaching  273 t 3,797  05S t 22 375
 247 t 26,763

Teaching & nonteaching  980 t 4,296  170 t 22,790
 40 t 2S 5S2

Teaching  53t53  0 to 
SOt 50 

Nonprofit  Nonteaching  64 t 29 372  991 t 23  454 t 33 9S1

Teaching & nonteaching  24,017 t 31,172  014 t 23 492  15,S97 t 34,

Teaching  0 t 0
 428 t 428  549 t 549

Government  Nonteaching  23,361 t 16 296  13,072 t 1S,912  12,S10 t 26 028

Teaching & nonteaching  68 t 16 536  65S t 1S 705  99 t 2S S56

Teaching  15S t 3,136  S57 t 857
 061 t 3 272

All  Nonteaching  -4,00 t 32777  128 t 40 511
 502 t 51,

Teaching & nonteaching  119 t 32,736  22,905 t 40
 14,786 t 51 503

100-29 bes 
Teaching  422 t 23,159  no 
 13,067 t 24 362

Profit  Nonteaching  898 t 32,538  682 t 1S,14O
 696 t 37 lS5

Teaching & nonteaching  031 t 4O,S91  765 t 1S,552
 172 t 44,764

Teaching  171 t 63 188  165 t 1 165  783 t 62,

Nonprofit  Nonteaching  7S,18O t 80 372  519 t 3O 35S  470 t 84 748

Teaching & nonteaching  44 t 102069  23 t 30,192  29S t 104,711

Teaching  9S2 t 14 S53  -6 t 68
 168 t 15

Government  Nonteaching  09 t 24 564  7S3 t 30 029  695 t 39 419

Teaching & nonteaching  508 t 30 721  520 t 30,119  353 t 43,

Teaching  631 t 68 739  862 t 1 352  393 t 68,250

All  Nonteaching  55,9S5 t 9O 57S  794 t 46 592  24,105 t 100 665

Teaching & nonteaching  771 t 113 748  656 t 46,603  38 t 121,49S

30+ bes 
Teaching  241 t 9,223  no case  241 t 9 223

Profit  Nonteaching  84 t 34  no case  036 t 34

Teaching & nonteaching  081 t 36 501  no case  203 t 36 619

Teaching  -61 40 t 135 144  28 t 28  -61 65S t 136 169

Nonprofit  Nonteaching  056 t 48 726  067 t 4 91S
 79S t 49 442

Teaching & nonteaching  249 t 141 709  030 t 5,526
 491 t 142

Teaching  04 t 33 347  0 to  971 t 34 524

Government  Nonteaching  302 t 32449 c  220 t 4,220
 601 t 32 292

Teaching & nonteaching  986 t 50 511  710 t 5 710
 S70 t 50 639

Teaching  507 t 142 069  319 t 319  54,S70 t 143 588

All  Nonteaching  62,677 t 66 S39  603 t 6  114 t 67 374

Teaching & nonteaching  14,750 t 155 074  921 t S 005  04 t 15627S

All hos itals 
Teaching  06 t 24,310  no  331 t 25,374 
Profit  Nonteaching  42,401 t 46,659  788 t 30 276  64 t 56,674 
Teaching & nonteaching  48,493 t 53,  867 t 30 905  51,04 t 62 163 
Teaching  050 t 149 711  222 t 1,477  421 t 150,417 
Nonprofit  Nonteaching  427 t 96 572  945 t 38,653  114 5S7 t 103,235 
Teaching & nonteaching  314 t 177 506  261 t 39 477  776t 180 
Teaching  26 t 38 625  123 t 1,467  48,707 t 38 916 
Government  Nonteaching  -62 502 t 45 440  16,529 t 35 97S  45S t 57 35S 
Teaching & nonteaching  26,220 t 60,762  721 t 36 586  -42 577 t 69 213 
Teaching  261 t 157 S10  175 t 1,993
 370 t 15S 889 
All  Nonteaching  435 t 116 S33  461 t 62,095
 80,149 t 130 976 
Teaching & nonteaching  031 t 195 422  60 t 63,419
 777 t 203 531 
A'7  . Appendix 20: Projected reimbursment effect by patient demography, 1988 
00 
$1, :I standard error  Male  Female  Male & female 
0-6  ears

White  663 :I 45  635 :I 30,676  48 :I 55,154

Black  17,672:1 17 213  588 :I 2,588  14,S31 :I 17

Other  416 :I 12,287  lS5 :I 4 lS5  23,530 :I 15,716

Unknow  no  0:1.0  0:1 0

All race  256 :I 53  S19 :I 31,465  80,463 :I 62 732

65-74  yea 
Whte  143 013:1 S5 467  716 :I 102 5S1  152,761 :I 133 345 
Black  34 :I 40 930  803:1 23,056  568 :I 45 907 
Other  0:1 0  23 :I 2  574 :I 2,574
Unknow  0:1 0  0:1 0  0:1 0 
All race  167,744 :I 95 675  -2,472 :I 109  171 44:1 145,456 
75-8  ears 
White  567:1 68;377  438 :I 73  257 :I 100 462 
Black  lS5 :I 24,276  732 :I 34,  31,24 :I 40 929 
Other  S14 :I 2 S14  0:1 0  610 :I 3,610 
Unknow  0:1 0  .0 :I 0  0:1 0 
All race  13,036 :I 73,Sl1  33,86 :I Sl 22O  936 :I 109,669 
S5 + yea 
White  104,544 :I 61,224  434 :I 39  110 15S :I 66 285 
Black  356 :I 5,654  -6,419 :I 3 71S  757 :I 6 91S 
Other  0:1 0  345 :I 2 345  263 :I 2 263 
Unknown  0:1 0  676 :I 1 95S  S37 :I 2, 
All race  112 980 :I 61,041  303 :I 39 739  113,912 :I 66 405 
All ae:es

White  -43,605 :I 131 152  74,612 :t 135 160  716 :t 188,l1S 
Black  12,28 :t 49 467  025 :t 37  411 :t 62,247 
Other  737:t 21,508  462 :t 6 124  429 :t 24 544 
Unknow  O:t 0  38 :t 6  7S9 :t 7,704 
All race  SlS :t 144 193  9S,99 :t 144 046  777 :t 203 531  (%) 
Appendix 21: DRG fruency, errr freuency, and errr proportion by proportion of errrs, 1988 
DRG desription 
Craniotomy for trauma age ::=lS

Spinal proure  1\0 (0.

proure  1\0 (0.

Peripheral & crnial nelVe & other nelVOUS sytem  age ::=70 &/or cc
Nonspeifc cerebroasular disorders with cc  1\0 (0.)

Nonspefic cerebroasular disorders w/o cc  1\0 (0.)

Traumatic stupor & coma, coma ::1 hr  1\0 (0.)

Concussion age ::=70 and/or cc
 1\0 (0.

Concusion age 1S-69 w/o cc
 1\0 (0.)

Other disrders of the eye age ::=lS w/o cc
 1\0 (0.

proure  1\0 (0.)

Salivar gland  except sialoadenectomy

Ear, nOs & throt malignancy
 1\0 (0.)

Nasl trauma & deformity
 1\0 (0.)

Major chest trauma age -:70 w/o cc
 1\0 (0.)

Pneumothora age ::=70 and/or cc
 1\0 (0.

Pneumothora age -:70 w/o cc
 1\0 (0.

102  Other repiratory diagnos age -:70  1\0 (0.)

11S  Cardiac pacemaker pulse generator replacement only  1\0 (0.)

126  Acute & subacute endocrditis
 1\0 (0.

152  Minor small & large boel proure age ::=70 and/or cc
 1\0 (0.)

164  Appendectomy with complicated principal diagnosis age:: =70 and/or cc
 1\0 (0.

173  Digestive malignancy age -:70 w/o cc
 1\0 (0.

17S  Uncomplicated peptic ulcer -:70 w/o cc
 1\0 (0.)

1S7  Dental exractions & restorations
 1\0 (0.)

193  Bilary tract proure except total cholectectomy age ::=70 &/or cc
 1\0 (0.

194  Bilary tract proure except total cholectectomy age -:70 w/o cc
 1\0 (0.)

199  Hepatobiliary diagnostic proure for malignancy  1\0 (0.)

201  Other hepatobiliary or pancrea OR proures 1\0 (0.

202  CilThosis & alcoholic hepatitis
 1\0 (0.)

221  Knee proures age ::=70 and/or cc
 1\0 (0.

224  Upper exremity proures except humeru & hand age -:70 w/o cc
 1\0 (0.

proure  1\0 (0.)

227  Soft tisue  age -:70 w/o cc

232  Arhropy
 1\0 (0.

235  Fracture of femur
 1\0 (0.)

237  Sprains, strains, & disloctions of hip, pelvis & thigh
 1\0 (0.)

O!\teomyelitis
 1\0 (0.)

242  Se'ptic arthritis
 1\0 (0.)

259  SiJbtotal mastectomy for malignancy age :: =70 and/or cc  1\0 (0.

262  Brest biops & locl excision for non-malignancy  1\0 (0.

Skin grafts for skin ulcer or cellulitis age -:70 w/o cc  1\0 (0.

269  Other skin, subcutaneous tissue & breast OR procure age :: =70 &/or cc  1\0 (0.)

274  Malignant bret disrders age :: =70 and/or cc  1\0 (0.

285  Amputations for endocrine, nutritional & metabolic disorders  1\0 (0.

287  Skin grafts & wound debride for endocrine, nutritional & metabolic disrders  1\0 (0.

292  Other endocrine, nutritional & metabolic OR procure age ::70 &/or cc 1\0 (0.)

Endocrie disorders age ::=70 and/or cc  1\0 (0.

. 1\0 (0. 
301  Endocrine disorders age -:70 w/o cc 
Kidney, ureter & major bladder procure for  1\0 (0.)

non-malignancy age ::=70 &/or cc 
31S  Kidney & urinary tract neoplasms age :: =70 and/or cc  1\0 (0.

323  Urinary stones age :: =70 and/or cc  1\0 (0.

334  Major male pelvic proure with cc  1\0 (0.

339  Testes procure, non-malignant age :: = 1S  1\0 (0.)

342  Circumcision age ::=lS  1\0 (0.)

357  Uteru & adnex proures, for malignancy  1\0 (0.

363  D&C, coniztion & radioimplant, for malignancy  1\0 (0.

Infections, female reprouctive sytem  1\0 (0.)

394  Other OR procure of the bloo & bloo forming organs  1\0 (0.)

397  Cogulation disrders
 1\0 (0.)

399  Reticuloendothelial & immunity disorders age -:70 w/o cc  1\0 (0.)

420  Fever of unknown origin age 1S-69 w/o cc  1\0 (0.)

447  Allergic rections age ::=lS  1\0 (0.

Signs & syptoms w/o cc 1\0 (0.

471  Bilateral or multiple major joint procure of lower exremities  1\0 (0.

474  Respiratory sytem diagnosis with tracheotomy  1\0 (0.

476  Protatic or proure unrelated to principal diagnosis  1\0 (0.)

1\0 (0.)

Peripheral & cranial nelVe & other nelVOUS system procure age -:70 w/o cc
Multiple sclerois & cerebellar ataa  2\0 (0. 
2\0 (0.)
 '\(\ 
Cranial & peripheral nerve disrders age ..70 w/o cc
 2\0 (0. 
Other disrders of nervous sytem age ..70 w/o cc 
Exraoclar proure except orbit age:. = 1S
 2\0 (0. 
2\0 (0.)

-44  Acute major eye infections

proure  2\0 (0.)

Sinus & mastoid  age :.=lS

2\0 (0.

Other ear, nos & throat diagnos age:. = 

2\0 (0.

Major chest trauma age :.=70 and/or cc

2\0 (0.

RespiratOlY signs & syptoms age ..70 w/o cc

168  Proure on the mouth age:. =70 and/or cc  2\0 (0.)

1S9  Other digestive system diagnos age 18-69 w/o cc  2\0 (0.)

2\0 (0.)

217  Wound debridement & skin graft except hand for musculoskeletal & connective tissue disorders
Lol  2\0 (0. 
excision & removal of internal fIXtion devce of hip & femur
231  Lol exciion & removal of internal fIXtion devce except hip & femur  2\0 (0.)

233  Other musuloskeletal sytem & connective tisue OR proure age:. =70 &/or cc  2\0 (0. 
245  Bone dis & septic arthropathy age ..70 w/o cc  2\0 (0.)

2\0 (0.

253  Fracture, sprains, strains & disloctions of upper arm, lower leg except foot age :.=70 &/or cc  2\0 (0.

Trauma to the skin, subcutaneous tisue & bret age:' =70 &lor cc  2\0 (0.)

302  Kidney transplant 
2\0 (0.

324  Urinary stones age ..70 w/o cc

2\0 (0.

338  Testes proures, for malignancy 
2\0 (0.)

354  Non-radical hysterectomy age:. =70 and/or cc

2\0 (0. 
355  Non-radical hysterectomy age ..70 w/o cc

Myeloproliferative disrder or porly diferentiated neoplasm with minor OR proure
 2\0 (0.)

2\0 (0.)

41S  Postoprative & pot-traumatic infections

2\0 (0.)

Hyprtensive encephalopathy
 3\0 (0. 
. Neurological eye disorders 
3\0 (0. 
oc head & neck procures 
3\0 (0. 
Epistas 
3\0 (0. 
105  Cardiac valve procure with pump & w/o cardiac catheterition  3\0 (0. 
115  Permanent cardiac pacemaker implant with AMI or CHF

3\0 (0. 
146  Rectal retion age:. =70 and/or cc

proure  3\0 (0. 
159  Hernia  except inguinal & femoral age:. =70 and/or cc

3\0 (0. 
179  Infammatory bowel disese

3\0 (0. 
Disorders of the bilary tract age ..70 w/o cc 
3\0 (0. 
219  Loer exremity & humerus procures except hip, foot, femur age 1S-69 w/o cc

225  Foot proures
 3\0 (0. 
228  Ganglion (hand) proures
 3\0 (0.)

3\0 (0.)

249  Aftercare, musuloskeletal sytem & connective tisue

261  Brpst proure for non-malignancy except biopsy & locl excision
 33\\00  ((00..))


271  Ski ulcers

3\0 (0.)

283  Minor skin disrders age:. =70 and/or cc

3\0 (0. 
290  Thyrid procures

3\0 (0.)

Minor bladder procures age:. =70 and/or cc
 3\0 (0. 
Lymphoma or leukemia with major OR procure

3\0 (0. 
Lymphoma or leukemia age 1S-69 w/o cc

Intraocr proure  3\0 (0. 
except retina, iri & lens
 4\0 (0. 
172  Digestive malignancy age:. =70 and/or cc

Upper exremity procure except humeru & hand age:. =70 and/or cc
 4\0 (0.)

4\0 (0. 
247  Signs & syptoms of musuloskeletal sytem & connective tissue

proure
 4\0 (0. 
341  Penis 
4\0 (0. 
350  Inflmmation of the male reproductive system

443  Other OR procure for injuries age ..70 w/o cc
 4\0 (0.)

4\0 (0. 
113  Amputation for circulatory system disorders except upper limb & toe

5\0 (0. 
128  Dep vein thrombophlebitis

5\0 (0. 
134  Hyprtension

5\0 (0. 
1155S7   AAnnaall  pprroocuurreess  aaggee :... 7=07 w0 /aon cd/co
r cc  5\0 (0. 
5\0 (0. 
1Sl  Gastrointestinal Obstruction age ..70 w/o cc

proure  5\0 (0. 
21S  Lower exremity & humerus  except hip, foot, femur age:. =70 &/or cc

5\0 (0. 
325  Kidney & urinary tract signs & symptoms age :'=70 and/or cc

5\0 (0. 
356  Female reproductive system recnstructive procures
 5\0 (0. 
Craniotomy age :.=lS except for trauma

6\0 (0. 
Nervous system neoplasms age :.=70 and/or cc

Lens proures
 6\0 (0. 
arrt
 6\0 (0. 
129  Cardiac 
6\0 (0. 
205  Disorders of liver except malignancy, cirrhosis, alcoholic hepatitis age :.=70 and/or cc

6\0 (0. 
Bone disese & septic arthropathy age:. =70 and/or cc

6\0 (0. 
35S  Uteru & adnex procure for non-malignancy except tubal interrpt
 6\0 (0. 
Major chest procures

160  Hernia procure except inguinal & femoral age 1S-69 w/o cc
 7\0 (0. 
7\0 (0.  27S  Cellulitis age 1S-69 w/o cc

316  Renal failure w/o dialyis
 7W (0. 
Exracrnial vasular proure
 7\0 (0. 
8\0 (0. 
- 131
 Peripheral vascular disrders age ..70 w/o cc

257  Tota mastectomy for malignancy age  =70 and/or cc
 S\O (0.)

321  Kidney & urinary tract infections age 1S-69 w/o cc
 9\0 (0. 
Fracture of hip & pelvs  9\0 (0.)

10\0 (0. 
116  Permanent cardiac pacemaker implant w/o AMI or CHF

14\0 (0. 
395  Red bloo cell disrders age  =lS

123  Circulatory disorders with AMI, exire
 14\0 (0.)

250 (0. 
410  Chemotherapy

Major joint proures
 34\0 (0. 
55\1 (l. 
140  Angina petori

Spefic cerebroasular disrders  S9\2 (2;2) 
except tia 
75' (2. 
336  Transurethrl protatectomy age  =70 and/or cc 
31\1 (3.
337  Transurethral protatectomy age ..70 w/o cc  29 
(3.4) 
Respiratory binfeycti ons & inflammations age  =70 and/or cc 
23\1 (4. 
106  Coronary  with cardiac catheterition 
17\1 (5. 
294  Diabetes age  =36 
Transient ishemic attacks  17\1 (5. 
47\ (6. 
223996   PNautthroitlioogniacla &l f mraicstculrlean &eo musu msueltoasbkoelliect adli smoradliegrnsa angce y  =70 and/or cc 44\3 (6. 
14\1 (7. 
125  Cirulatory disrders except AMI, with cardiac catheterition without complex diagnosis  2S 
(8.0) 
Simple pneumboniay &  pleurisy age  =70 and/or cc  74\6 (S. 
107  Coronary  w/o cardiac catheterition 
12\1 (S. 
Pulmonary embolism 
11\1 (9.

Bronchitis & asthma age  =70 and/or cc

63\6 (9.

127  Heart failure & shock

215  Back & neck proures age ..70 w/o cc
 133\13 (9.

10\1 (10.)

Seizure & headache age  =70 and/or cc 
20\2 (10. 
122  Circlatory disorders with AMI w/o CV complications discharged alive 
475  Respiratory sytem diagnosis with ventilator  30\3 (10.)

197  Total cholectectomy w/o CDE Age  =70 and/or cc
 19\ (10.

148  Major small & large bowel procures age  =70 and/or cc
 31S3\\42  ((1121.. )

174  Gastrointestinal Hemorrhage age  =70 and/or cc

311  Transurethral proures age ..70 w/o cc
 33\4 (12. 
415  OR proure for infectious & paraitic disese
 S\l (12.

112  Vascular procures except major recnstruction
 S\l (12.

32\4 (12.5) 
143 
121  I9recsut  paaitno 
 ry ISO!' erAsM WI
 it comp lcatlons ISC arg a Ive  3328\\45  ((1123..5 ) 
243  Medical back problems

proure  22\3 (13. 
214  Back & neck  =70 and/or cc

age 
303  Kidney, ureter & major bladder procure for neoplasm
 7\1 (14.

310  Trnsurethral procures age  =70 and/or cc
 7\1 (14.

110  Major renstructive vascular procure age  =70 and/or cc
 7\1 (14.

130  Peripheral vascular disorders age  =70 and/or cc  21\ (14.

proure  13\2 (15. 
442  Other OR  for injuries age  =70 and/or cc 
13\2 (15.4) 
138  Cardiac arrhythmia & conduction disrders age  =70 and/or cc 
45\7 (15. 
139  Cardiac arrhythmia & conduction disorders age ..70 w/o cc 
416  Septicemia age  =lS  19\ (15.

31\5 (16. 
25S  Total mastectomy for malignancy age ..70 w/o cc 
142  Syncope & collaps age ..70 w/o cc  6\1 (16.

162  Inguinal & femoral hernia proure  12\ (16.

age 1S-69 w/o cc 
12\2 (16. 
Respiratory neoplasms 
proure  24\4 (16. 
210  Hip & femur  except major joint age  =70 and/or cc 
154  Stomach, esphageal & duodenal proure age  =70 and/or cc  2131\\42  ((1lS7..4 ) 
124  Circulatory disrders except AMI with cardiac catheterition & complex diagnosis
1S2  Esphagitis, gastronteritis & miscllaneous  21\4 (19. 
digestive disorders age  =70 &/01' cc  6613 (19. 
Seizure & headache age 1S-69 w/o cc 
109  Cardiothoracic procures w/o pump  5\1 (20.

150  Peritoneal adhesiolysis age  =70 and/or cc  55\\11  ((2200.
.) 
161  Inguinal & femoral hernia procures age  =70 and/or cc 
315  Other kidney & urinary tract OR procures  5\1 (20.

331  Other kidney & urinary tract diagnos age  =70 and/or cc  5\1 (20.

39S  Reticuloendothelial & immunity disorders age  =70 and/or cc  5\1 (20.

5\1 (20.

Disorders of pancres except malignancy

10\2 (20. 
320  Kidney & urinary tract infections age  =70 and/or cc 
40\8 (20.)

141  Syncope & collaps age  =70 and/or cc 
Diseuilbrium  19\4 (21.)

195  Total cholectectomy with CDE Age  =70 and/or cc  9\ (22.

9\2 (22.

" 1
 359	 Tubal interrption for non-malignancy 
452  Complications of tretment age;: =70 and/or cc
 9\2 (22.

1S3  Esphagitis, gastronteritis & miscllaneous digestive disorders age 1S-69 w/o cc
 9\ (22.

- 36	 Retinal proure  22\5 (22. 
Otitis media & upper repiratory infection  4\1 (25.

age 1S-69 w/o cc 
177	 Uncomplicated peptic ulcer ;:=70 and/or cc  4\1 (25.

Other musuloskeletal system & connective tisue OR proure age c:70 w/o cc 4\1 (25.

254  Fracture, sprains, strains & disloctions of upper ann, lower leg except foot age 1S-69 w/o cc  4\1 (25.

461  OR proure with diagnos of other contact with health servce  4\1 (25.

Aftercare w/o history of malignancy as sendary diagnosis  4\1 (25.

Respiratory infections & inflammations age 1S-69 w/o cc
 4\1 (25.

'17  Disorders of the bilary tract age;: =70 and/or cc
 S\2 (25. 
188  - Other digestive sytem diagnos age;: =70  S\2 (25. 
and/or cc

449  Toxc effects of drugs age ;:=70 and/or cc
 11\3 (27. 
297  Nutritional & misllaneous metabolic disrders age 1S-69 w/o cc
 7\ (28.

proure 14\4 (28.

Unrelated or 
OR proure on the repiratory sytem except major chest with cc
 21\6 (28.

Carpl tunnel relea
 10\3 (30.

3\1 (33.3)

Pleurl effusion age ;:=70 and/or cc

111  Major renstructive vasular proure age c:70 w/o cc
 3\1 (33.

155  Stomach, esphagea &p duroodeunarl  proure age 1S-69 w/o cc
 3\1 (33.

170  Other digestive sytem  age ;:=70 and/or cc
 3\1 (33.

176  Complicated peptic ulcer
 3\1 (33.

Protatecomy age;: =70 and/or  3\1 (33.

332  Other kidney & urinary tract diagnos age  3\1 (33.

1S-69 w/o cc

450  Toxic effects of drugs age 1S-69 w/o cc
 3\1 (33.3)

Degenerative nelVous sytem disrders
 3\1 (33.

149  Major small & large boel proure age c:70 w/o cc
 6\ (33.

175  Gastrointestinal Hemorrhage age c:70 w/o cc
 6\ (33.

'13  Malignancy of hepatobilary system or pancreas
 66\\  (33.

263  Skin grafts for skin ulcer or cellulitis age;: =70 and/or cc
 (33.3)
6\ 
419  Fever of unknow origin age;: =70 and/or cc
 (33.3) 
180  Gastrointestinal Obstruction age;: =70 and/or cc
 6\ (33.

Pulmonary edema & repiratOl)' failure  15\5 (33. 
Bronchitis & asthma age 1S-69 w/o cc
 '1\7 (35.

14\5 (35. 
277  Cellulitis age ;:=70 and/or cc

104  Cardiac valve procure with pump & with cardiac catheterition
 19\7 (36. 
144  Other circulatory diagnos with cc
 5\2 (40.

19S  Total cholectectomy w/o CDE Age c:70 w/o cc
 10\4 (40.)

10\4 (40. 
Chronic obstructive pulmonary disease 
211	 Hip & femur procures except major joint age 1S-69 w/o cc
 21\9 (42. 
Simple pneumonia & pleurisy age 1S-69 w/o cc
 9\4 (44.4)

Otitis media & uri age;: =70 and/or cc
 22\10 (45. 
OR proure on the respiratory system except major chest w/o cc
 2\1 (50.

135  Cardiac congenital & valvular disorders age;: =70 and/or cc
 2\1 (50.

151  Peritoneal adhesioIyis age c:70 w/o cc
 2\1 (50.

2\1 (50.) 
216  Biopsies of musculoskeletal sytem & connective tissue

222  Knee proure age c:70 w/o cc
 2\1 (50.

241  Connective tisue disrders age c:70 w/o cc
 2\1 (50.

Tendonitis, myositis & bursitis
 2\1 (50.

2\1 (50.) 
270  Other skin, subcutaneous tissue & brest OR procure 
age c:70 w/o cc

Minor skin disorders age c:70 w/o cc
 2\1 (50.

2\1 (50.) 
299  Inborn errors of metabolism

305  Kidney, ureter & major bladder procure for non-malignancy age c:70 w/o cc
 2\1 (50.

440  Wound debridements for injuries 
 2\1 (50.) 
455  Other injuries, poisonings & toxic effects diagnosis age c:70 w/o cc
 2\1 (50.

2\1 (50.) 
462  Rehabiltation

473  Acute leukemia w/o major or procure age;:17
 2\1 (50.

NelVous sytem neoplasms age c:70 w/o cc
 2\1 (50.

4\2 (50.) 
Cranial & peripheral nelVe disorders age;: =70 and/or cc

101  Other respiratory diagnos age;: =70 and/or cc
 4\2 (50.

191  Major pancreas, liver & shunt procures
 4\2 (50.

4\2 (50.

Malignancy, male reproductive sytem, age;: =70 and/or cc

421	 Viral ilnes age ;:=lS  4\2 (50.

6\ (50.

Other disorders of nelVous system age;: =70 and/or cc

403	 Lymphoma or leukemia age ;:=70 and/or cc  S\ (60.

Respiratory signs & syptoms age ;:=70 and/or 5\3 (60.

1 '1  Other OR proures on the circulatory sytem  S\5 (62.5) 
1S5  Dental & oral disse except exractions & restorations age ;:=lS 3\2 (66. 
413  Other myeloproliferative disorder or porly differentiated neoplasm diagnosis age;: =70 &/or cc  3\2 (66.

3\2 (66.
 132	 Atheroslerois age :: =70 and/or cc

Traumatic stupor & coma, coma oe 1 hr age :: =70 and/or cc
 4\3 (75.

Miscllaneous ear, nos & throat proure
 1\1 (100.) 
- 92  Interstitial lung disese age ::=70 and/or cc  1\1 (100.

Interstitial lung disse age oe70 w/o cc
 1\1 (100.

133  Atherolerois age :'70 w/o cc
 1\1 (100.

1\1 (100.

136  Cardiac congenital & valvular disorders age 1S-69 w/o cc

Hepatobilary diagnostic proure for non-malignancy  1\1 (100.

1\1 (100.

Connective tisue disorders age ::=70 and/or cc

265	 Skin grafts except for skin ulcer or cellulitis with cc  1\1 (100.

Skin, subcutaneous tissue & breast plastic proures
 1 \1 (100. 
307  Prostatectomy age oe70 w/o cc
 1\1 (100.

335  Major male pelvc proures w/o 
 1\1 (100.

Benign protatic hyprtrophy age :: =70 and/or 
 1\1 (100.

365  Other female reprouctive sytem OR proures
 1\1 (100.

1\1 (100.

Malignancy, female reprouctive sytem age :: =70 and/or cc

367  Malignancy, female reproductive system age oe70 w/o cc
 1\1 (100.

401  Lymphoma or leukemia with minor OR procure age :: =70 and/or cc
 1\1 (100.

Myeloproliferative disorder or neoplasm with major OR proure & 1\1 (100.

463  Signs & syptoms with cc 1\1 (100.

Nontrumatic stupor & coma  1\1 (100.

117  Cardc pacemaker replace & reion except puls generator replacement only  2\ (100.

145  Other circulatory diagnos w/o  2\ (100.

153  Minor small & large boel proures age oe70 w/o cc  2\ (100.

213  Amputations for musculoskeletal system & connective tisue disrders  2\2 (100.

453  Complications of treatment age oe70 w/o cc  2\2 (100.

3\3 (100.

Total 
2451\31 (14.  Appendix 22: Mean weight, dollar change, and estimated national financial effect by DRO, 1988 
DRO desription  Mean chan2e t standard errr  National effect 
Relative weight  ($1,00) 
00 t 0. 
Craiotomy age  =lS except for trauma
 o t 0
 o t 0

=lS  00 t 0.  o to 
SCrpainnioatlo pmy rfoor utrrauema  age  00 t 0.  o t 0

o t 0
 o t 0

proures  00 t 0. 
Exracranial vasular  o t 0
 o t 0

Carpl tunnel relea  0270 t 0.0270  84t84  S32 t S32

PPeerirpiphehrealr a&l  &cr acnriaaln inaell Vnee alVgee  prou=r7e0  aagned /0o:r7 c0c w /o cc  0000  tt  00..   oo  tt o0
  oo  tt  00


NelVous sytem neoplasms age  =70 and/or cc  00 t 0.  o t 0
 o t 0 
NelVous sytem neoplasms age c:70 w/o cc  1481 t 0.1036  461 t 322
 095 t 4 263 
Degenerative nelVous sytem disrders  -0.1054 t 0.0679  328 t 211
 509 t 4 195 
Multiple sclerois & cerebellar ataa  00 t 0. 
o t 0
 o t 0 
Spefic cerebroasular disorders except tia  017S t 0.0281  59 t 86
 80 t 21,381 
Transient ishemic attacks  0455 t 0.0395  138 t 122
 539 t 19 033 
Nonspeific cerebroasular with cc  00 t 0. 
o t 0
 o t 0

Nonspeifc cerebroasular disrders w/o  00 t 0. 
o t 0
 o t 0

Peripheral nelVe age  ;"70 and/or cc  -0.136 t 0.  -425 t 
 621 t 3,434 
Crnial &  00 t 0.  o to 
peripheral nelVe age c:70 w/o cc o t 0

Hypensive encephalopathy  00 t 0.  o to 
o t 0

Nontraumatic stupor & coma  20 t 0.2376  66 t 734  362 t 4,845 
Seizre & headache age  =70 and/or cc  -0.0052 t 0.24  16 t 76
 062 t 5,019 
Seizure & headache age 1S-69 w/o cc
 -0.0157 t 0.0157  -49 t 49
 -8 t 80

Traumatic stupor & coma  1 hr  00 t 0.  o to  o t 0

Traumatic stupor 0:1 hr age  =70 and/or cc  -0.24 t 0.  -650 t 0
 146 t 0

Concusion age  =70 and/or cc  00 t 0.  o t 0
 o t 0

Concusion age 1S-69 w/o cc  00 t 0.  o t 0
 o t 0

NelVous sytem age  =70 and/or cc  -0.0591 t 0.1383  120 t 392
 986 t 6,47S 
Other nelVous system age c:70 w/o cc  00 t 0.  o to 
o t 0

Retinal procures  0071 t 0.0071  22t22  292 t 292

Lens proures  00 t 0. 
o t 0
 o t 0

Exraocular procures  =lS  00 t 0.  o to 
Intraocular proure eexxcceeppt t orrebtiitn aag, ei ris  00 t 0.  o t 0

o t 0
 o t 0

Acute major eye infections  00 t 0. 
o t 0
 o t 0

00 t 0. 
Neurological eye disrders
 o t 0
 o t 0

Othejro rd ihsoeradder s& o fn etchek  epye raoge ure  =lS w/o cc
 0000  tt  00..   o to  o t 0

o t 0
 o t 0

Salivary gland except sialoadenectomy  00 t 0. 
Sinus & mastoid proure  =lS  00 t 0.  o t 0
 o t 0

age  o t 0
 o t 0

Miscllaneous ear, nos & throat procures  1561 t 0.  411 t 0
 35S t 0

Ear, nos & throat malignancy  00 t 0. 
o t 0
 o t 0 
Disuilbrium  0175 t 0.0116  54 t 36
 619 t 1 071 
Epistas  00 t 0. 
o t 0
 o t 0

Otitis media & uri age  =70 and/orcc  -0.0334 t 0.0334  -87 t S7
 580 t 580

Otitis media & uri age 1S-69 w/o cc  019S t 0.019S  61 t 61
 S16 t S16

Nasl trauma & deformity  00 t 0.  o t 0
 o t 0

Other ear, nos & throt diagnos age  =lS  00 t 0.  o t 0
 o t 0

procures  00 t 0. 
or chest  o t 0
 o t 0 
OR repiratory except major chest with cc  -0.2452 t 0.1329  764 t 414
 227 t 13 673 
OR procure on the respiratory except chest w/o cc  045 t 0.045  80 t 80 
122 t 122

Pulmonary embolism  0542 t 0.0542  142 t 142
 186 t 5 186 
Respiratory infections age  =70 and/or cc  -0.038 t 0.38  120 t 120
 174 t 9,174 
Respiratory infections age 1S-69 w/o cc
 0.870 t 0.940  271 t 293
 15S t 7 737 
Respiratory neoplasms  -O.09S2 t 0.0494  30 t 154
 24,24 t 12 
Major chest trauma age  =70 and/or cc  00 t 0.  o t 0
 o t 0

Major chest trauma age c:70 w/o cc  00 t 0.  o to 
o t 0

Pleural effusion age  =70 and/or cc  -0.0410 t 0.0410  108 t 108
 069 t 1 069 
Pulmonary edema & repiratory failure  -0.1915 t 0.  570 t 
 671 t 13 643 
Chronic obstructive pulmonary disese  -0.003 t 0.0540  22 t 168
 572 t 11 647 
Simple pneumonia age  =70 and/or cc  042 t 0.024  134 t 74
 S32 t 1S 153 
Simple pneumonia age 1S-69 w/o cc  242 t 0.756
 704 t 205
 15S t 14,955 
Interstitial lung ddisiesse eag e  =70 and/or cc  -0.4557 t 0.  420 t 0
 689 t 0

Interstitial lung  age c:70 w/o cc  -0.041 t 0.  143 t 0
 -474 t 0

Pneumothora age  =70 and/or cc  00 t 0.  o t 0
 o t 0

Pneumothora age c:70 w/o cc  00 t 0. 
o t 0
 0 t 0 
Bronchitis & asthma age  =70 and/or cc  -0.00 t 0.0104  2 t 30
 447 t 6 
Bronchitis & asthma age 1S-69 w/o cc
 0570 t 0.0356  168 t 107
 794 t 4 948 
'\4  Respiratory signs age  =70 and/or cc  2896 t 0.1515  80 t 397
 229 t 10 496 
100  Respiratory signs & syptoms age c:70 w/o cc  00 t 0.  o t 0
 o t 0

101  Other repiratory age  =70 and/or cc  -O.089S t 0.0703  279 t 219
 694 t 2,S95 
- 102
 Other repiratory diagnos age c:70  00 t 0.  o t 0  o t 0 
104  Cardiac valve with pump & cardiac catheterition  5763 t 1.2239  914 t 3 S16  -81 09 t 62 
105  Cardiac valve with pump & w/o cardiac catheterition  00 t 0. 
o t 0
 o t 0

106  Coronary byss with cardiac catheterition  -0.0739 t 0.0739  23 t 23  12,92 t 12,920 
107  Coronary byssp wr/oo ucarredi ac catheterition  104 t 0.104  326 t 326
 92 t 12, 
109  Cardiothoracic  w/o pump  -0.1777 t 0.1777  554 t 554
 141 t 9,141 
110  Major vascular age  =70 and/or cc  -O.21S9 t 0.120  -6 t 376  -47,295 t 26,103 
111  Major renstructive vasular age c:70 w/o 
 4693 t 0.4693  463 t 1,463  48 t 14 
112  Vasular procures except reconstruction
 0611 t 0.0693  190 t 216  130 t 22,S12 
113  Amputation except upper limb & toe  00 t 0. 
o t 0
 o t 0

115  Cardiac pacemaker implant with AMI or CHF  00 t 0.  o to  o t 0 
116  Cardiac pacemaker implant w/o AMI or CHF  00 t 0.  o to  o to 
117  Cardiac pacemaker replacement except pulse generator  6697 t 0.S736  765 t 2,303  11,656 t 15, 
11S  Cardac pacemaker generator replacement
 00 t 0.  o t 0  o t 0 
proure 
120  OR  on the circulatory sytem
 -0.3202 t 0.3813  99S t 1,188  88 t 11,770 
121  AMI & CV complications discharged alive
 -0.0627 t 0.0269  188 t Sl
 693 t 10 169 
122  AMI w/o CV complications disharged alive
 0108 t 0.034  25 t 103
 512 t 10 235 
123  Circulatory disrders with AMI, exired  00 t 0. 
o t 0
 o t 0 
124  Circulatory except AMI with card catheterition
 -0.0396 t 0.0459  112 t 137
 777 t 9 559 
125  Circulatory except AMI with card catheterition
 01S9 t 0.0197  5S t 61
 86 t 5 077 
126  Acute & subacute endocrditis
 00 t 0.  o to  o to 
127  Heart failure & shock
 0491 t 0.0263  153 t Sl
 67,522 t 35 
128  Deep vein thrombophlebitis  00 t 0.  o to 
arrt
 o t 0

129  Cardiac  00 t 0. 
o t 0
 o t 0

130  Peripheral vasular age  =70 and/or cc
 00 t 0.0071  22 t 1S
 974 t 

131  Peripheral vascular disorders age c:70 w/o cc  00 t 0.  o to 
o t 0

132  Atherolerois age  =70 and/or cc
 -0.081 t 0.0679  211 t 179
 788 t 2,3 
133  Atherolerois age -:70 w/o cc
 -0.0745 t 0.  232 t 0
 767 t 0 
134  Hyprtension
 00 t 0.  o to 
o t 0

135  Cardiac congenital age  =70 and/or cc
 -0.0123 t 0.0123  32 t 32  213 t 213

136  Cardiac congenital age 1S-69 w/o cc
 2432 t 0.  75S t 0  502 t 0

138  Arhythmias age  =70 and/or cc  -0.0190 t 0.0215  59 t 66  80 t 9,938 
139  Arhythmia & conduction age -:70 w/o cc  04 t 0.0267  149 t S3  38 t 5 224 
140  Angina petori
 0026 t 0.0036  6 t 9  035 t 2,801 
141  Sycope & collaps age  =70 and/or cc  0126 t 0.0325  43 t 100  736 t 6 296 
142  Sypcope & collaps age c:70 w/o cc  0217 t 0.0150  61 t 41  434 t 1,654 
143  Chest pain  06 t 0.041 
199 t 150  08 t 15,S53 
144  Other circulatory diagnos with cc  -0.0586 t 0.0255  lS2 t 79  033 t 2 625 
145  Other circulatory diagnos w/o  1995 t 0.331S  653 t 1 002  315 t 6 61S 
114468   RLeocetarl  pGrersIt oipounr oargcee u re ag=e 70 a=n7d0/o arn cdc/or cc  -0.0006  tt  00.. 0784  201 to  2t2 10

 21,952 t 24o  1t4 20
 
149  Bowel  age c:70 w/o cc  701S t 0.3138  075 t 933
 09 t 1S, 
150  Peritoneal adhesiolyis age  =70 and/or cc  -0.23 t 0.232  742 t 742
 257 t 12,257 
151  Peritoneal adphersoioulyirse a ge -:70 w/o cc  5956 t 0.5956  S57 t 1 S57  257 t 12 257 
152  Minor boel proure age  =70 and/or cc  00 t 0.  o t 0
 o t 0

111555543    MUUppippneeorrrp   GGbrIIoo  eppul rrrooecu ureres  aagge ea g1Se=- c67:970 0 wa /wnod /oc/o ccr c c c  --00..331762653071   ttt   000...623576415537    3891316 4t   2tt  ,90S42607
   -40 54355244  7tt   t13 309 
 054279  
157  Anal  =70 and/or cc  00 t 0. 
15S  Anal procure aagge e c:70 w/o cc 00 t 0.  o t 0
 o t 0

159  Hern except inguinal age  =70 and/or cc  00 t 0.  oo  tt  00

 oo  tt  00


160  Hernia except inguinal age 1S-69 w/o cc  00 t 0.  o to 
o t 0 
161  Hernia procures age  =70 and/or cc  0.4967 t 0.4967  548 t 1 548  554 t 25 554 
162  Inguinal hernia procures age 1S-69 w/o cc  lS51 t 0.1634  566 t 509  452 t 20,164 
164  APprpoenudreceto my age  =70 and/or cc 00 t 0.  o t 0
 o t 0

168  porno thue rmoeut h age  =70 and/or cc  00 t 0.  o to  o t 0 
170  Digestive  age  =70 and/or cc  -O.5S13 t 0.5S13  S12 t 1 S12  943 t 17 943 
172  Digestive malignancy age  =70 and/or cc  00 t 0.  o t 0
 o t 0

173  Digestive malignancy age c:70 w/o cc  00 t 0. 
o t 0
 o t 0

174  GI hemorrhage age  =70 and/or cc  06 t 0.  216 t 
 525 t 29,276 
175  GI Hemorrhage age c:70 w/o cc  1093 t 0.0691  34 t 215  746 t 4 
176  Complicated peptic ulcer  -0.0273 t 0.0273  -85 t S5
 -8 t 844 
177  Uncomplicated peptic ulcer  =70 and/or cc  0511 t 0.0511  134 t 134
 779 t 1,779 
I7S  Uncomplicated peptic ulcer c:70 w/o cc  00 t 0.  o to 
o t 0

179  Inflammatory bowel disese  00 t 0.  o to  . 0 t 0

180  GI Obstruction age  =70 and/or cc  -0.0714 t 0.0336  210 t 96
 10,40 t 4 786 
1Sl  GI Obstruction age ':70 w/o cc  00 t 0. 
o t 0
 o t 0

'i'i  11SS32   UUppppeer  ggaassttrrooiinntteessttiinnaall  dagie:s: = 7ag0e a 1nSd-/6o9r  cw/co  cc
 0149124  tt  00..01354211   517299  tt  417036

 4228,,015240  tt  3243,  133 
1S5  Dental & oral except exractions age ::=lS
 5944 t 0.  S53 t 1211
 34 t l1 9S9 
- 1S7
 Dental exractions & retorations
 00 t 0. 
o t 0
 o t 0 
188  Other digestive diagnos age ::=70 and/or cc
 0.887 t 0.670  271 t 
 S39 t 7 572 
119S19   MOtahjeorr  dpiagnecsrteivaes ,s lyivteemr & ag seh u1nSt- 6p9r ow/cou crce
s
 1.05014 t t  00.. 667  313 t 1o,  t 0
 -43 732 t 25o  4t2 40  
193  Bilal) tract procure age:: =70 and/or cc
 00 t 0.  o to 
194  Bilal) .tract procure age c:70 w/o cc
 00 t 0.  o t 0

195  Cholectectomy & CDB age:: =70 and/or 
 -0.1338 t 0.0899  390 to  2t6 70

 5S3 t 7o  9t3 10 

197  Cholectectomy w/o CDB age:: =70 or cc
 -0.08 t 0.05S1  263 t 1Sl
 673 t 10,751 
1199S9   HChepolaetcotbeiclatol)m py rwo/ou CreD Bfo Ar mgea lcig:7n0an wc/yo
 cc
 0300  tt  00.. 124  S76 to  3t5o9 
 92 t 11 S7S 
201  HHeeppaattoobbiillaall))  porr opaunrcer ef oOr Rno np-mroaluignraen cy
 05502 1t  t0 0..   455o  tt o0 
 80o  tt  00
 
202  Cirosis & alcoholic hepatitis
 00 t 0.  oo  tt o0
 
o t 0

203  DMiaslridgennrsc yo of fp haenpcarteob eilxicael)p to mr palaignncanrcey
  --00..01164311  tt  00..0952084   31742  tt  218393

 6S9566  tt  54  472208  
205  Liver except malignancy, age ::=70 and/or cc
 00 t 0.  o t 0
 o t 0 
207  BDiilsiradl)e trrsa octf  atghee  :b:=il7a0l)  atnradc/ot ra gcce
 c:70 w/o cc
 20602 8t  t0 0.. 2626  S19 t SlS
 21,633 t 21o,6 t1o5  
o t 0

221110   HHiipp o ppr rrjroonunutrr eper o eexcxcucerepeptst  j
jooiinntt  aaggee :1: S=-7609  awn/do/ occr 
cc
 --00..020151624216   ttt   000... 00713446   755-504  5tt   t
2 2485

 2-288,,342374 4t   tt 1 S7S,  392617904   
213  Amputations for musuloskeletal
 0.3 t 0. 
proure  055 t S55
 967 t 5, 
221154   BBaacckk  &&  nneecckk  procure aaggee  c:::7=07 0w a/on dc/co
r cc
 --00..01442525  tt  00..01445252   -143513  tt  143513

 10-,447,S3 t  t1 04 4,73S  
216  Biopsies of musculoskeletal
 -0.0937 t 0.0937  292 t 292
 927 t 1,927 
217  Wound debridement & skin graft except hand

21S  Loer exremity proure age:: =70 and/or cc
 1.00609 0t  t0 1.. 0690
 333 t 3o,3 t3o3   21,99 t 21, 
219  Loer exremity & humeru proure  00 t 0.  o t 0

221  Knee proures age:: =70 and/or cc
 age 1S-69 w/o cc
 00 t 0.  oo  tt o0 
 o t 0

proure  o t 0

222  UKnpepee r exremity pagreo cu:7r0e w /o cc
 0176 t 0.0176  46t46  305 t 305

age:: =70 and/or cc
 1256 t 0.1256  331 t 331
 370 t 4,370 
224  Upper exremity procure age c:70 w/o cc
 00 t 0. 
Foot proures
 00 to.  oo  tt o0 
 o t 0

227  Soft tissue proures age c:70 w/o cc
 00 t 0.  o t 0

Ganglion (hand) procures
 00 t 0.  oo  tt o0 
 o t 0

Lol excision internal fIXtion devce of hip & femur
 00 t 0.  oo  tt o0 

231  ybl excision except hip & femur
 00 t 0.  oo  tt o0
 
232  Arhrospy
 00 t 0.  o t 0

223353   MMFruuascstuuullrooessskk oeeflle eftteaamll  OuOrRR    pprroouurree  aaggee  :c::7=07 0w a/on dc/co
r cc
 0002008  2tt   t00 0... 0 282  88oot  8tt  800 

 162 t 1ooo    1ttt6  o200 
  
o t 0

Fracture of hip & pelvi  00 t 0.  o to 
237  Sprains, strains, & disloctions  00 t 0.  o t 0

o t 0
 o t 0

Osteomyelitis  00 t 0. 
239  Musuloskeletal & connective tissue malignancy  002 t 0.062
 19 ot  t1 90

 S97 to  St9 70


Connective tissue age:: =70 and/or cc
 193Ot 0.  601 t 0
 986 t 0

241  Connective tissue disorders age c:70 w/o cc  2310 t 0.2310  720 t 720
 753 t 4,753 
242  Septic arthritis  00 t 0.  o to 
o t 0

243  BMoendeic aarlt bharockp aptrhoyb laegmes : :=70 and/or cc  00106 9t  t0 0.. 0145  52 t 45
 SlS t 3,289 
245
 Bone & septic arthropathy age c:70 w/o cc  00 t 0.  oo  tt o0 
 o t 0

247
 Signs & syptoms of musculoskeletal  00 t 0.  oo  tt o0 

o t 0

Tendonitis, myositis & bursitis  0.391 t 0.391  80 t 80 
121 t 121

249  Aftercare, musuloskeletal & connective tissue  00 t 0. 
253  Fracture, sprains, strains & disloctions age ::=70 and/or cc  00 t 0.  o t 0
 oo  tt o0
 
o t 0

254  Fracture, sprains, strains & disloctions age 1S-69 w/o cc  2917 t 0.2917  90 t 90  12,005 t 12,005 
257  Total mastectomy age ::=70 and/or cc  00 t 0. 
o t 0
 o t 0 
25S  Mastectomy for malignancy age c:70 w/o cc  0331 t 0.0331  103 t 103
 043 t 2 043 
259  Mastectomy malignancy age ::=70 and/or 
 00 t 0. 
261  Breast proure for non-malignancy except biopsy  00 to.  o t 0
 oo  tt o0
 
o t 0

262  Breast biopsy & excision for non-malignancy  00 t 0. 
263  Skin grafts for skin ulcer age:: =70 and/or cc  -0.2911 t 0.2679  777 to  7t0 S0

 38 t 13o 9t6 70  
Skin grafts for ulcer age c:70 w/o cc  00 t 0. 
265  Skin grafts except for ulcer or cellulitis with cc  -0.704 t 0.  196o  tt  00

 24o  tt  00 

Skin, subcutaneous tissue & breast procures 
269  Skin, subcutaneous & breast procure age:: =70 and/or cc  -0.01303 6t  t0 0..   -416 t 0
 -1,375 t 0 
270  Skin, subcutaneous & breat OR age c:70 w/o cc  -0.1020 t 0.1020  317 to  3t1 70

 09S t 2o  0t9 S0   271  Skin ulcers
 00 t 0.  o to 
274  Malignant brest age  =70 and/or cc
 00 t 0.  o t 0

277  Cellulitis age  =70 and/or cc
 1330 t 0.1224  373 to  3t5 50

 23,40 t 22o,  t 0

- 27S
 Cellulitis age 1S-69 w/o cc
 00 t 0. 
283  MTirnaoru mskain  todi ssokridner, s& a gber est age =70 =an7d0/ oanr dc/co
r cc
 0000  tt  00..   ooo   ttt  o00
 
 oo  tt  00


o t 0 
Minor skin disrders age 0:70 w/o cc
 144 t 0.144 
285  Amputations for endocrine & metabolic
 00 t 0.  450 to  4t5o0
  971 t 2 971 
287  Skin grafts & debridement for metabolic disorders
 00 t 0.  o t 0

290  Thyrid proures  00 t 0.  o t 0
 oo  tt o0
 
292  Nutritional & metabolic OR proure  00 t 0.  o t 0

222999746   .  NNDuiutatrbrieitttieosin oaanlga el&   m&e tmaeb=otl3aib6co  lagiec  age 1S-=6790  wa/nod c/oacg
re  cc 70 and/or cc  020100017795   ttt   000...00110372852    6572 13t o tt 42 t33 3520
 

 30,:323562570   ttt   2150o    031t023 1700    
Inborn errrs of metabolism
 lS73 t 0.lS73  584 t 584
 S54 t 3 S54 
Endocne disrders age  =70 and/or cc  00 t 0.  o to 
301  Endocne disrders age 0:70 w/o cc  00 t 0.  o t 0

302  Kidney transplant  00 t 0.  oo  tt o0
  oo  tt o0
 
303  UUrriinnaarryy  tprarcot uprreo unorn-ema lfiogrn annecoy palgaes m  =70 and/or cc  -0.00403 8t  t0 0.. 0438  136 to  1t3o6
  157 t 3 157 
333311001075

   TTPBPUrrrrloroaaatindnatnatdassetureceuyorrcrme  epptyto htarrhmrgooareyl lu u  paprrgrreeeoos  0u fu:oa7gr=rer0e  7ne s0wo   n/aaao-=gngme 7 dea0/ o0l ia:rg7=n nc0d7ac /0wn o c/raoy nc  cdaccg/ o
er 0 c:c7
0 w/o cc  ---0000....2000142200098059  71tt   t   ttt 0 0  0000......   04122980971    556361 -468t   29tt19o      t65 3ttS51  496600  
    2701536 4t   tt 19 20So3o,     21ttt73   54000
    
315
 Other kidney & urinary tract OR proures
 34 t 0.
 023 t 17 023 
316
 Renal failure w/o dialysis  -0.00 t 0.
 062 t 1o,0 t6o2   531 t 17o  5t3o1  
31S
 Urinary tract neoplasms age  =70 and/or cc  00 t 0.

332210

 UUrriinnaarryy  trtarcatc ti nifnecfteicotniso nagse  age 1S-=6790 w a/nod c/ocr
 cc  -0.00309 2t  t0 0.. 0202  122 ot  t6 10

 132 t So, lt2 50  
323
 Urinary stones age  =70 and/or cc  00 t 0.  oo  tt o0 
 oo  tt o0
 
324
 Urinary stones age 0:70 w/o cc
 00 t 0.  o to 
325
 Urinary tract signs age  =70 and/or cc  00 t 0.  o t 0

333312

 UOthreinr aurryin atrray ctrt adcti aaggen os age= 710S -a6n9d w/o/ro  cccc

 -0.0130141  tt  00..0130141   97 ot  t9 70

 602 t 1o, 6t0 20 

334
 Major male pelvic procures with 
 00 t 0.  326 t 326
 228 t 3 228 
335
 Major male pelvc procures w/o 
 5157 t 0.  607o  tt  00

 30o  tt  00 

336
 ?,nsurethral protatectomy age  =70 and/or cc  -0.0105 t 0.0105  32 t 32
 36 t 3 
333378

 T1;erasntseusr eptrhoracl uprreot,a ftoerc mtoamliyg naagnec y0
:70 w/o cc 00101 3t  t0 0.. 0113  29t29  845 t 2 845 
334319

 TPeensist eps rporouurrees
 , non-malignant age  =lS
 0000  tt  00..   ooo   ttt  o00 

 oo  tt  00


342
 Circumcision age  =lS
 00 t 0.  o t 0

o t 0
 o t 0

Malignancy, male reprouctive age  =70 and/or cc  -0.1227 t 0.1194  323 t 314
 271 :t 4 155 
Protatic hyprtrophy age  =70 and/or cc
 242 t 0. 
767 t 0
 533 :t 0 
350  Inflmmation male reproductive sytem
 00 t 0. 
354  Non-radical hysteretomy age  =70 and/or cc
 00 t 0.  o t 0
 o t 0

355  Non-radical hysterectomy age 0:70 w/o cc
 00 t 0.  o t 0
 o t 0

356  Female reprouctive renstructive proures
 00 t 0.  o t 0
 o t 0

357  Uteru & adnex procures malignancy
 00 t 0.  o t 0
 O:t 0

35S  Uteru & adnex procure for non-malignancy
 00 t 0.  oo  tt o0 
 O:t 0 
336539   TDu&baCl , icnotnerizrtpitoino n& f roard inoo-ni-mmpallaingtn amnaclyi
gnancy  00807 0t  t0 0.. 0576  271 t 179
 059 :t 5O :3t3 00
 
365  Other female reproductive OR proures  1.077 t 0.
 o t 0
 o t 0

453 t 0
 39S :t 0 
Malignancy, female reproductive age  =70 or cc  1469 t 0.

367  Malignancy, female reproductive age 0:70 w/o cc  45S t 0
 512 t 0

5435 t 0.

Infections, female reproductive sytem  00 t 0.  694 t 0
 592 t 0

394  OR proure bloo & bloo forming organs 00 t 0.  o t 0
 o t 0

395  Red bloo cell age  =lS  00 t 0.  o t 0
 O:t 0 
397  Cogulation disorders  00 t 0.  o t 0
 o t 0

3399S9   RReettiiccuuloleonednodtohetlhiealli aagle  age 0:7=07 0w/ aon dcc/o
 r cc  00104 9t  t0 0.. 0149  39 ot  t3 90

 650 to  6t5 00


Lymphoma or leukemia major OR procure  00 t 0.  o t 0
 o t 0

o t 0
 O:t 0 
444000143    LLLyyympmmhpopmhhao oommr aal e ouOkrRe lm eiuap kraegoemc iuar aeg ea g1e S-=679=0 w 7a0/no da c/nocd r/ occr  cc  --00..06347094 54t   tt0  00...  1534  1030 2t5  4t5 00

 202 6t8 37  4t3 90  
406  MMyyeelloopprroolliiffeerraattiivvee  worit hne mopaljaosrt iOc Rw ipthr omciunroer  O&R c pcr ocure 09703 5t  t0 0..   153o  tt  00

 20,30o  tt  00
 
410  Chemotherapy  00 t 0.  o t 0
 O:t 0 
o t 0
 o t 0
 413  Myeloproliferative or neoplasm age  =70 or cc  6295 t 0.6540  970 t 2 035  19,510 t 20 147 
415  OR proure for infectious & parasitic  -0.3252 t 0.3252  -857 t S57  22,64 t 22, 
416  Septicemia age  =lS  0.207 t 0.0740  64 t 23  616 t 23 
- 41S	 Postoperative & pot-traumatic infections  00 t 0. 
0 t 0  0 t 0 
419  Fever of unknow origin age  =70 and/or cc  -O.019S t 0.0767  -61 t 239  220 t 4 734 
420  Fever of unknow origin age 1S-69 w/o cc  00 t 0.  0 t 0  0 to 
421  Viral ilnes age  = 1S  2911 t 0.2374  88 t 740  504 t 14 65S 
Wound debridements for injuries  -0.861 t 0.861  706 t 2,706  17,863 t 17,863 
442  Other OR for injuries age  =70 and/or cc
 -0.0163 t 0.067  50 t 214  lS3 t 9 lS9 
443  OR proures for injuries age c:70 w/o cc
 00 t 0. 
0 t 0  0 t 0 
447  Allergic rections age  = 1S
 00 t 0.  0 t 0  0 t 0 
449  Toxic effects of drugs age  =70 and/or cc  0276 t 0.0327  88 t 101  036 t 2,342 
445502   TCooxmcp elifcfeactitosn osf  odfr turgestm aengte  a1gSe -69 w/=o7 c0c  and/or cc  21020 2t  t0 0..1108062   638172  tt  351S22   42059 2t.  t1 73  301 
453  Complications of trtment age c:70 w/o cc  4903 t 0.106  416 t 219  020 t 2 169 
455  Injuries, poisnings & toxc age c:70 w/o cc
 0550 t 0.0550  171 t 171  131 t 1 131 
461  OR proure with diagnos of other contact
 4370 t 0.4370  362 t 1,362  9S7 t 17 9S7 
462  Rehabiltation
 -0.6397 t 0.6397  994 t 1,994  164 t 13 164 
463	 Signs & syptoms with cc
 442 t 0. 
385 t 0  571 t 0 
Signs & syptoms w/o cc
 00 t 0. 
471  AMUfnutlertlriacptrleeed  mw Oa/ojRo hr  pijsotrionorty up orrfeo m uarliegn oanfc ylo
wer exremities  -0.00340159 4t   tt 0 00... 10443544   112481  tt00    14tt4 4 0170     19866 t t  3100   t 0 
473  Acute leukemia w/o major OR procure age  -0.7123 t 0.7123  220 t 2,  657 t 140  6t5 70  
474  Respiratory sytem with tracheotomy  00 t 0. 
447765   PRreosptairtaicto OryR w pithr oveunrtiela tuonrr seulaptpeodr tt o diagnosis  -0.02503 5t  t0 0.. 138  790 t0  4t3 00   -49 568 t 260  9tS 10  
0 t 0  0 t 0 
Total  0023 t 0.0070  7 t 21  401 t 173 214 
4:R  Appendix 23: HCF A comments  ...
Health Care
DEPARTMENT OF HEALTH & HUMAN SERVICES 
Financing Administration 
Memorandum 
"'''10 
MAY 2 9 

Date 
From  Wilam Toby; Jr.

Actig Admintrtor

Subject 
OIG Draft Report: "National DRG Valdation Study Update: Summary

Report" (OEI-12-89-O190) and "National DRG Valdation Study Update:

Technical Report" (OEI-12-89-O191)

Inspector General 
Offce of the Secretary 
dr 
We have reviewed the above-referenced 
report which are

updates to a previous OIG study which re-abstrctd the International

Clasification of Diseaes 9th Edtion, Clica Modcation coes from a

saple of 1985 Medicae discharges. Thes report update the previous study

cog 
by: replicating the 1985 work on  accuracy using 1988 data comparg

the findings from 1985 and 1988, and identig pattrns of cog errors that

the Prospectie Payment System (PPS) changes cold mod. 
The saple

was nationally representative and covered al of caenda yea 
1988, the most

recnt year for which data were available. 
OIG found a signifcat improvement in hosita cog of PPS cas 
, between 1985 and 1988. In the 1985 study, OIG found that 20.8 percent of 
cog 
contaed  diosc 
. 1985 Par A bil  errors that changed the  related 
group (DRG) and that 61.7 percent of thes errors over-reimbursd the 
cog 
hospitals. This improper DRG  diurments 

incread tota PPS 
mion. Durig 
9 percent or $308  the 1988 study, OIG found that

cog 
14.7 percent of the diharges had-DRG  errors 51 percnt of DRG

errors over-reimbursed the hospita and 49 percnt under-reimburd the

hospita. Taken together, the 1988 DRG errors rested in no net

overpayment of hospita.

We believe thes report are a useful addition to the contiuing 
cae mi  hosita 
. research and evaluation of  change among 
paid under PPS.

We agree with OIG' s recommendation that Peer Review Organtions

contiue their surveilance of hospita cong of DRG reimbursment

accuracy. Our detailed comments on these two report are attcbed for your

consideration.
 Page 2 - Inspector General 
Thank you for the opportnity to review and comment on these draft 
report. Please advise us if you agree with our position on the report' 
recommendation at your earliest convenience. 
Attachment  . '
Comments of the Health Care Financing Administration (HCFA)
on OIG's Draft Reports: "National DRG Validation Study Update: 
Summary Report" OEI-12-89-00190 and "National DRG Validation 
Study Update: Technical Report" OEI-12-89-00191 
OIG Recommendation 
The Peer Review Organizations (PROs) should continue their surveilance of 
hospital coding for DRG reimbursement accuracy. 
HCF A Response

We agree. The PROs wil continue their surveilance of hospital coding of 
diagnostic related group (DRG) reimbursement 
accuracy. 
We are pleased to note the decrease in DRG 
coding errors identifed by the 
1988 study, as compared to the 1985 study. We believe this improvement may 
be attributed to a combination of factors including 
increased hospital
, experience under the prospective payment system (PPS), the impact of PRO 
review and the effect of HCFA educational efforts to enhance 
coding accuracy. 
General Comments 
Summary Report. OEI-12-89-00190 
1 This 

report includes a brief but excellent description of the payment process 
including the role of coding. Three tyes of errors are defined at each stage of
the payment process. However, no statement is made as to whether or not the 
report. 
errors are mutually exclusive, and if the 361 records with errors contained only 
1 of each tye. We believe this information should be included in the final
Although the representativeness of the sample is thoroughly addressed
, there is
no discussion as to how adequately each DRG is represented. 
We would like 
to know how the distribution by DRG of the sample relates 
to the universe of 
DRGs, and if any correlation exists between high volume DRGs and errors 
the sample. Also, we note that most hospitals contributed only one discharge
to the sample. We question whether it is statistically valid for 
1 record in 1 hospital to represent 3 300 other records in the total population 
of records.

It is not made clear in the report how 
payment projections are calculated. The 
amount used to estimate payment is not stated, although mention is made  - "
Page 2

of using a rate of $3 118 for metropolitan hospitals and $2 637 for 
nonmetropolitan hospitals (page 29, Technical Report). It is stated that these 
are "current dollars " but there is no discussion as to the actual figures used to 
project payment amounts. While the 
calculation for case-mix index (CMI) is 
clearly defined, as is the DRG difference before and after coding, it is not
clear how the payment amount is determined. The final report 
should include 
a more complete description of payment calculation. 
Executive Summary, page ii  DRG coding errors, overall, no longer over-

reimburse hospitals." The figure for under-reimbursements is stated to be

588.0 bilion." The correct figure is $2 588 millon (also Executive
Summary, page iii, Technical. Report). 
Findings, pages 5, 9 - While it is unwise to ignore magnitudes and only pay

attention to statistical significance, we do not believe effects that are not

statistically significant should be highlighted. For example, the report notes
that for-
profit hospitals "over-reimburse themselves" but that "these results did 
not attain statistical significance" (also CMI discussion, pages 13, 14, Technical
Report). 
Findings, page 6 - The narrative incorrectly 
states that the overall CMI 
decreased after the study s recoding. For hospitals to have underpaid

themselves, the CMI would have to increase after recoding, as is correctly

stated on page 13 of the Technical Report. 
Findings, page 6, Figure 6 - The 1988 pie chart does not match the numbers in 
the text immediately below the chart. The 
resequenced and miscoded pieces
of the pie do not represent the 27 
percent and 9 percent respective figures and 
may have been reversed in the pie chart. 
Technical Report 
, not 476. 
Introduction, page 1, paragraph 3 - The original number of DRGs in 
1983 was 
470
Introduction, page 1, paragraph 4 - The narrative implies that there is a fiscal 
intermediary for each State. The 
sentence should be rewrtten to state: " 
fiscal intermediary receives the hospital bils for each State.  . . .
Page 3

Page 2, paragraph 3, under the heading "The HCFA. . . made the following 
points in commenting on the 1985 Study" - It was HCF A' s intent to point out 
that the 1985 study was published in November 1987; and conclusions set forth 
in that report were based in part on information and coding conventions which 
had been updated by the time the report .was released. The phrasing " 
needed a longer learning period to adjust to the new payment and quality 
monitoring system" does not encompass the concept that changes have been 
made to the whole International Classification of Diseases, 9th Edition, Clinical 
ModifcationlProspective Payment SystemlDRG system since its conception. 
Such changes and improvements continue to be made. 
Page 4 - We do not believe the data support some of the assertions and 
language which the report uses. For example, the report describes the findings
of the earlier OIG report as showing "intentional. gaming . or manipulating (of 
the 1 coding process" by hospitals. The note cites unrelated sources while the 
earlier report used much more restrained language. 
The report consistently characterizes coding disagreements as provider "errors. 
A recent Rand study used charts re-abstracted at SuperPRO to examine the 
1987-88 increase in the Medicare CM!. Rand estimated that changes in coding 
common to SuperPRO and hospitals accounted for almost one-third of the 
1987-88 CMI increase. Since SuperPRO coders have no incentive to upcode
this probably reflects changes in explicit and implicit coding rules between 
original coding (1987) and recoding (1988). While the CMI may increase
1 payments to hospitals will not. However
, disagreements which may reflect the 
evolution of coding practice over time are not strictly provider "errors." Rand 
and OIG studied slightly different problems, and the Rand findiIJg may be 
unique to 1988. However, since American Medical Records Association staff 
should be able to provide insight on this matter, we recommend that OIG 
explore and report on the question of whether the increase in the CMI is 
attributable to provider errors or the evolution of coding practices. 
Page 4, paragraph 3 - "Each year, the relative weights change to reflect 
alterations in resource consumption, DRG title, coding and. . ..
" The change
title of the DRG. 
in relative weights is not related to the  .. . . 
' ..
c. 
Page 4

Page 10 - The report does not fid net overpayment due to coding error. 
Inclusion of a table of DRGs with "maxmum savings potential (to Medicare)" 
due to upcoding, without a parallel table of DRGs with maxmum potential 
payment increase, gives an impression of lack of balance. Financial impact 
(savings) estimates could be presented in the context of the argument that 
while ". . . trends to over-pay and under-pay approximately offset each other, 
this equilbrium may not continue in the
' future. 
Page 12 - OIG reports that coding errors (incidence of coding error capable 
influencing DRG assignment) declined signifcantly between 1985 and 1988. . 
While true, the report overstates the change. The 
1985 report used a two-
stage sampling design and reported error rates for the nation  8 percent 
of 20.
(hospital-weighted) and 18.6 percent (case-weighted). The update report finds 
a 1988 error rate of 14.7 percent but compares it to the 1985 hospital-weighted 
statistic. The 1988 value, based on a simple random sample of cases
, is 
equivalent to a case-weighted statistic and should not be compared with 
hospital-weighted value. 
Page 15 - Some PPS details in the draft report are obscured. For example, the 
report discusses "base payment amounts" when it means standardized amounts. 
Discussion of reimbursement effects states that financial impacts "paralleled
CMI changes" when they are simply calculated from and are logically 
equivalent to such changes.

" Appendix 5 - There appears to be an error for hospitals with 300 or more 
beds. The response rate of 66.8 percent should be changed to 48.9 percent 
(1, 199 responses of 2 451). 
There is some disagreement between the narrative and the appendices. Table 
9 ilustrates the number of records per DRG and the number miscoded. 
Appendix 21 lists each DRG with the number of records selected and the 
error frequency and the proportion of errors. Whle the number of records 
selected is consistent between the table and the appendix the number of 
errors is not. There is no indication why these numbers differ, the source 
this data, or which is correct. However, the errors reported in appendix 21 do
total 361, the correct total for the study.