Department  of Health  and Human  Services 
OFFICE  OF

NSPECTOR  GENERAL

DRG  121  VALIDATION  STUDY  UPDATE: 
CIRCULATORY  DISORDERS  WITH 
MYOCARDIAL  INFARCTION  AND 
CARDIOVASCULAR  COMPLICATIONS 
OCTOBER 1992
 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  Department  of Health  and  Human 
Services  (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: 
the  Office  of Audit  Services,  the  Office  of Investigations,  and  the  Office  of Evaluations 
and  Inspections.  The  OIG  also informs  the  Secretary  of HHS  program  and 
management  problems  and  recommends  courses  to correct  them. 
OFFICE OF AUDIT SERVICES 
The  OIGS Office  of Audit  Services  (OAS)  provides  all auditing  services  for HHS, 
either  by conducting  audits  with its own audit  resources  or by overseeing  audit  work 
done  by others.  Audits  examine  the  performance  of HHS  programs  and/or  its 
grantees  and  contractors  in carting  out  their  respective  responsibilities  and  are 
intended  to provide  independent  assessments  of HHS  programs  and  operations  in 
order  to reduce  waste,  abuse,  and  mismanagement  and  to promote  economy  and 
efficiency  throughout  the  Department. 
OFFICE OF INVESTIGATIONS 
The  OIGS Office  of Investigations  (01)  conducts  criminal,  civil, and  administrative 
investigations  of allegations  of 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. 
OFFICE OF EVALUATION AND INSPECTIONS 
The  OIGS Office  of Evaluation  and  Inspections  (OEI)  conducts  short-term 
management  and  program  evaluations  (called  inspections)  that  focus  on issues  of 
concern  to the  Department,  the  Congress,  and  the  public.  The  findings  and 
recommendations  contained  in these  inspection  reports  generate  rapid,  accurate,  and 
up-to-date  information  on the  efficiency,  vulnerability,  and  effectiveness  of 
departmental  programs. 
Amy L. Lockwood  of BOTEC  Analysis  Corporation  prepared  this report  with 
direction  from  Janet  W. Knight,  BOTEC  Project  Director,  and  David  C. Hsia,  OIG 
Project  Officer.  Contract  information  and  project  participants  are  listed  in Appendix 
A to this inspection.  Department  of Health  and Human  Services 
OFFICE  OF

NSPECTOR  GENERAL

DRG  121  VALIDATION  STUDY  UPDATE: 
CIRCULATORY  DISORDERS  WITH 
MYOCARDIAL  INFARCTION  AND 
CARDIOVASCULAR  COMPLICATIONS 
OCTOBER 1992  OEI-12-89-00194
 EXECUTIVE  SUMMARY

PURPOSE 
This inspection  reabstracted  on a blinded  basis, the  International  Classification  of 
Diseases,  9th Edition,  Clinical  Modification  codes  from  a sample  of Medicare 
discharges  billed  as diagnosis-related  group  (DRG)  121.  It compared  the  reabstracted 
DRGtothe  hospital-billed  DRGfor  reimbursement  changes.  The  sample  was 
nationally  representative  and  covered  all of 1988, the  most  recent  data  available. 
This  inspection  updated  a previous  Office  of Inspector  General  (OIG)  study.  For 
1985, the  OIG  found  17,7 percent  errors  among  76 reabstractions,  improperly  over-
reimbursing  hospitals  by a projected  $42.2 million.  This inspection  used  a parallel 
methodology  to make  these  studies  statistically  comparable.  Statistical  tests 
determined  whether  numeric  differences  between  1985 results  and  1988 results  were 
real  (statistically  significant)  or could be  attributed  to random  error. 
FINDINGS 
DRG  121 billing errors not reduced 
Of  115 discharges  reabstracted  for this inspection,  12.2 percent  had  billing  errors.  The 
difference  between  this result  and  the  17.7 percent  error  rate  the  OIG  found  for DRG 
121 discharges  in  1985 was not  statistically  significant.  Further,  the  difference  between 
this inspections  12.2 percent  error  rate  and  the  14.7 percent  errors  for all discharges 
in 1988 also  lacked  statistical  significance. 
Financial  impact  not reduced 
This  inspection  projected  that  DRG  121 billing errors  over-reimbursed  hospitals  $28,7 
million.  This  result  did not  statistically  differ  from  the  $42.2 million  over-
reimbursement  in 1985.  The  increase  in the  number  of DRG  121 bills in 1988 largely 
offset  the  decrease  in the  proportion  of errors. 
1  TABLE  OF  CONTENTS

EXECUTIVE  SUMMARY  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  i

TABLE  OF  CONTENTS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  ii

INTRODUCTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1

FINDINGS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4

DRG121billing  errornot  reduced  . . . . . . . . . . . . . . . . . . . . . . . . .  4

All errors  over-reimburse  the  hospitals  . . . . . . . . . . . . . . . . . . . . . . .  4

Over-reimbursement  continues  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4

Reasons  for errors  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5

ENDNOTES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6

APPENDICES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7

A  Project  participants  ..,....  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8

B: ICD-9-CM  codes  in DRG  121.....  . . . . . . . . . . . . . . . . . . . . . . . . . .  10

C: Sample  representativeness.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11

D: Proportion  of DRG  121 billing errors,  1985 and  1988 . . . . . . . . . . . . . .  12

E: DRG  121 case-mix  index  change,  1985 and  1988  . . . . . . . . . . . . . . . . .  13
 INTRODUCTION

Background

Diagnosis-related  group  (DRG)  121 includes  121nternational  CJassificationof

Diseases,  9th Edition,  Clinical  Modification  (ICD-9-CM)  codes.  The  ICD-9-CM  codes

may  appear  as either  principal  or secondary  diagnoses.  These  ICD-9-CM  codes

identify  complications  to cardiovascular  disease.  To group  to DRG  121, a bill must

have  codes  for both  an  acute  myocardial  infarction  and  cardiovascular  complications.

The  myocardial  infarction  must  have  occurred  within  eight weeks  of the  date  of

admission  for the  DRG  121 billing.  Either  diagnosis  may appear  as the  primary  or

secondary  diagnosis.  [Appendix  B].

DRG  121s weight  decreased  from  1.8454 in 1985 to  1.7162 in 1988.  In October  1989,

the  HCFA  altered  DRG  121 by adding  a fifth digit to ICD-9-CM  code  410 to identify

whether  a given  admission  is the  initial  or subsequent  treatment  for a myocardial

infarction.  This  change  deleted  the  rule  requiring  that  patients  with  an identified

myocardial  infarction  or a myocardial  infarction  in the  prior  eight  weeks  be  included  in

DRG  121.  This  change  did not  affect  the  period  of this study.

In a previous  study, the  OIG  found  that  DRG  121 had  a disproportionately  high

proportion  of billing  errors. 1  Correct  ICD-9-CM  coding  would  have  grouped  17.7

percent  of its 76 reabstractions  to different  DRGs  in 1985.  These  billing errors  over-

reimbursed  the  hospitals  a projected  $42.2 million.

This  inspection  updated  the  previous  study using  1988 data,  the  most  recent  available.

It used  a parallel  methodology  to make  these  inspections  statistically  comparable.

Methodology

This inspection  randomly  selected  115 DRG  121 discharges  from  42 hospitals.  The

study population  consisted  of the  142,312 Medicare-reimbursed  DRG  121 discharges

during  calendar  year  1988.  The  design  excluded  discharges  from  specialty  institutions

such  as childrens  hospitals,  tuberculosis  units,  and  psychiatric  facilities.  It also

excluded  discharges  in Maryland  and  New Jersey,  which  the  PPS still exempted  in

1988.  Finally,  it excluded  bills for pediatric,  obstetric,  and  psychiatric  DRGs

(principally  drug  and  alcohol  rehabilitation  performed  by a general  hospital).  Unlike

its 1985 predecessor,  it included  hospitals  established  since  the  advent  of the  PPS in

1983.

The  OIG  requested  that  hospitals  send  complete  copies  of the  sampled  medical

records  to the  OIGS contractor,  Baxter-Health  Data  Institute  (HDI)  of Lexington,

MA.  The  OIG  followed-up  missing records  and  issued  subpoenas  to compel  the

cooperation  of four  hospitals.

1
 The  OIG  contracted  with the  American  Medical  Record  Association  (AMRA)  to 
reabstract  the  charts.  The  AMRA  selected  ICD-9-CM  codes  supported  by the  record, 
determined  the  principle  diagnosis,  and  grouped  to select  the  correct  DRG.  To  assure 
that  the  original  ICD-9-CM  codes  and  DRGs  did not  effect  the  reabstraction,  the 
AMRA  coders  conducted  their  work without  knowledge  of the  original  ICD-9-CM 
codes  and  DRGs.  The  coders  had  instructions  not  to treat  marginal  problems  or 
honest  differences  in judgement  about  appropriate  coding  as DRG  errors.  This 
standard  should  have  produced  a conservative  estimate  of the  proportion  of discharges 
having  DRG  errors.  A series  of reliability  checks  verified  the  reproducibility  and 
accuracy  of the  AMRA  coding.  The  AMRA  also identified  the  reasons  why a 
hospitals  bill differed  from  the  correct  codes. 
BOTEC  Analysis  Corporation  of Cambridge,  Massachusetts  (BOTEC)  edited  the 
AMRA  database,  checked  the  samples  representativeness,  and  conducted  statistical 
analyses  of the  correlates  and  financial  consequences  of DRG  121 miscoding.  It also 
reweighted  the  1985 data  to improve  comparability  with this inspection.  The  t-test 
determined  whether  numeric  differences  between  1985 results  and  1988 results  were 
real  (statistically  significant)  or could  be  attributed  to random  error. 
Representativeness 
To  test  the  samples  representativeness,  the  OIG  compared  the  distribution  of sample 
bills to the  distribution  of the  underlying  population  of DRG  121.  The  sample  and 
population  did not  differ  significantly  with respect  to hospital  or patient  characteristics. 
[Appendix  C]. 
2
 Bedsize  Teachingstatus 
e. 
<100  ,@  100
1004?99
301)+  WwMii  @&i 
Nonteachlng 
Sample  Population  Sample  Population 
Location  Control 
Metropolitan
~Me71 
W..tmp!!2?..WW.  N-f@-Gpti 
Sample  Population  Sample  Population 
igure 1: Sample  representativeness  by hospital  demography,  1988 
Age  Sex 
a5-74  Male 
65-74  MaJe 
a4 
75-84  75-84 
;  98 
Female 
Sample  Population  Sample  Population 
Race 
3
 FINDINGS

DRG 121 billing error not reduced 
Of the  115 sample  discharges,  12.2  25  a 
percent  had  billing errors  that  changed 
t-
their  reimbursement  from  DRG  121.  20  -i  Year 
The  difference  between  this result  and   
1985 
the  17.7 percent  error  rate  the  OIG  15   
1988 
found  in 1985 was not  statistically  1
10 
significant.1  This  trend  applied  across 
most  hospital  and  patient  characteristics. 
5 
Small  hospitals,  for-profit  hospitals,  and  i 
younger  patients  showed  more  0 
DRG 121  AllDRGs 
improvement  in coding  accuracy. 
[Appendix  D]. 
~igure 3: Coding  errors,  1985 &  1988 
This  1985-1988 decrease  in the 
proportion  of billing  errors  exceeded  the  improvement  for all DRGs,  from  20.8 
percent  in  1985 to  14.7 percent  in 1988.  The  difference  between  this inspections  12.2 
percent  DRG  121 errors  and  the  14.7 percent  errors  for all DRGs  in  1988 was not 
statistically  significant.3 
All errors  over-reimbursethe hospitals 
Of the  14 billing  errors,  all over-reimbursed  to the  hospitals.  This proportion  did not 
improve  upon  the  100 percent  over-reimbursement  reported  for in 1985. 
Over-reimbursement  continues 
The  115 sample  discharges  originally  carried  Relative  Weights  of 1.8454, equivalent  to 
an average  payment  of $5,638.  The  AMRA  reabstraction  reduced  the  case-mix  index 
(CMI) by a statistically  significant  0.0675.  This reduction  persisted  across  most 
hospital  and  demographic  characteristics.  The  net  CMI  change  in 1988 did not  differ 
significantly  from  the  net  CMI  change  for DRG  121 in 1985.  [Appendix  E]. 
An  extrapolation  of the  CMI  change  in 1988 to all  142,312 DRG  121 discharges  from 
the  hospital  categories  included  in this sample  projected  that  billing  errors  over-
reimbursed  hospitals  a statistically  significant  $28.7 million.  This  over-reimbursement 
1. Because  of the  smaller  sample  size that  results  from  DRG-specific  analysis, 
estimates  of coding  for specific  DRGs  are  less precise  than  OIGS national  estimate. 
Statistical  tests  determined  whether  apparent  differences  were  real  (statistically 
significant)  or could  be  attributed  to random  error. 
4  did not  statistically  differ  from  the  $42.2 
million  over-reimbursement  in 1985.  $ miJon 
The  increase  in the  number  of DRG 
$ 
121 bills offset  the  nonsignificant 
improvement  in coding  accuracy. 
ii 
Reasons for errors  25 
The  AMRA  identified  only two types  of 
errors  in the  sample,  mis-specification 
and  other.  Mis-specification  caused 
o-
85.7 percent  of the  14 billing  errors.  1985  1988 
This  proportion  did not  statistically 
differ  from  in 1985.  Other  caused  the  Figure  4: Financial  impact  of miscoding 
remainder  of the  samples  billing errors.  DRG  121, 1988 & 1985 
This  proportion  also did not  statistically 
differ  from  1985. 
5  ENDNOTES

1. Stone  D, Kleiman  M, Meyers  M, Schutte  J, Lee  F, Hsia  D, & Krushat  M.  DRG 
121: Circulatory  disorders  with  acute  myocardial  infarction  and  cardiovascular 
complications.  Washington,  DC:  HHS  Officeof  Inspector  General,  1989.  Publication 
no. OAI-12-88-01210. 
2. Knight J W & Hsia  D C, eds.  National  DRG  Validation  Study Update:  Technical 
Report.  Washington,  DC:  HHS  Office  of Inspector  General,  1992.  Inspection  no. 
OEI-12-90-00191. 
3. Knight  J W & Hsia  D C, eds.  National  DRG  Validation  Study Update:  Summary 
Report.  Washington,  DC:  HHS  Officeof  Inspector  General,  1992.  Inspection  no. 
OEI-12-90-00190. 
6
 APPENDICES 
7  Appendix  A  Project  participants 
QIg 
Cathaleen  A. Ahern,  B.A.

Evan  J. Buckingham,  B.A.

David  C. Hsia,  J.D.,  M.D.,  M.P.H.

Thomas  F. Komaniecki,  M.P.A.

W. Mark  Krushat,  M.P.H.

Linda  M. Moscoe,  B.A.

Brian  P. Ritchie,  B.A.

Barry  L. Steeley2

John  M. Traczyk,  B.A.

HCFA

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

Stephen  F. Jencks,  M.D.

Michael  R. McMullan,  M.B.A.

Harry  L. Savitt,  Ph.D.

Jeanette  M. Smith,  M.D.,  M.P.H.3

Malcolm  A. Sneen,  B.S.

RAND  Corporation

Haya  P. Rubin,  M.D.,  Ph.D4

Baxter-Health  Data  Institute5

Patricia  J. Baxter,  R.N.

Patricia  Cassidy-Tsnosas,  R.N.

Annette  M. Delaney,  R. N., M.A.

Ellen  B. Inghilleri,  R.N.

Janet  Mathews,  A.R.T.

Laurie  H. Moore,  R.R.A.

Claire  Shannon,  A.R.T.

Michele  A. Wiese,  B.A.

AMRA

Margret  K. Amatayakul,  M.B.A.,  R.R.A.

Mary  Converse,  R.R.A.

Nicholas  J. Cotsonas,  M.D.b

Linda  Ertl,  R.R.A.

2. Now at Health  Audit  Services,  Ellicott  City, MD. 
3. Now at the  Journal  of the  American  Medical  Association,  Chicago,  IL. 
4. Now at Johns  Hopkins  Medical  Institutions. 
5. Ceased  operations  February  16, 1990. 
6. Outside  contractor. 
8  Rita  M. Finnegan,  R.R.A.

Desla  Mantilla,  A.R.T.

Barbara  Manny,  R.R.A.

Sonia  Martyniuk,  R.R.A.

Toula  Nicholas,  A.R.T.

Charlotte  Razor,  R.R.A.

LouAnn  Schraffenberger,  R.R.A.

Lynn  Smetko,  R.R.A.

Dawn  Smith,  A.R.T.

Joan  Zacharias,  A.R.T.

BOTEC  Analvsis  Corporation

Geraldine  M. Berenholz,  R.R.A.

Andrew  H.  Chalsma,  B.A.

David  P. Cavanagh,  M.A.,  Ph.D.

Janet  W. Knight,  R.N.,  Ph.D.

by  L. Lockwood,  B.A.

Contract  information 
Contractor

BOTEC  Analysis  Corporation

1698 Massachusetts  Avenue

Cambridge,  MA  02138

Proiect  Officer

David  Hsia,  J.D.,  M.D.,  M.P.H.

Office  of Inspector  General

3301ndependence  Avenue

Washington,  D.C.  20201

Contract

HHS-1OO-9O-OO23

Firm-fixed  price  contract

$203,257

9
 Appendix  B: ICD-9-CM  codes  in DRG  121 
402  hypertensive  heart  disease  with congestive  heart  failure

411.0  post-myocardial  infarction  syndrome

414  heart  aneurysm

415.1  pulmonary  embolism-infarction

426  atrioventricular  block

427  tachycardia

428  congestive  heart  failure

429  papillary  muscle  rupture

441.0  dissecting  aneurysm

458.9  hypotension

584  acute  renal  failure

785  shock

10  Appendix  C  Sample  representativeness 
Number  [percent]  Population  Sample  Chi-square 
Hospital  demomaphy 
1-99 beds  21,874 [15.4]  14 [12.2]  1.02, 2 df, P= O.400 
100-299 beds  55,381 [38.9]  49 [42.6] 
300+  beds  65,050 [45.7]  52 [45.2] 
Metropolitan  105,776 [74.3]  85 [73.9]  0.01, 1 df, P= O.071 
Nonmetropolitan  36,536  [25.7]  30 [26.1] 
Teaching  55,599  [39.1]  43 [37.4]  0.12, ldf,  P= O.264 
Nonteaching  86,713  [60.9]  72 [62.6] 
Profit  14,650 [10.5]  9 [7.8]  0.75, 1 df, P= O.61O 
Nonprofit  125,237 [89.5]  106 [92.2] 
Patient  demomaphy 
c65  years  8,061 [5.7]  2 [1.7]  3.46, 3 df, P= O.672 
65-74 years  56,834  [39.9]  52 [45.2] 
75-84 years  56,279  [39.5]  44 [38.3] 
85+  years  21,138 [14.9]  17 [14.8] 
Male  71,330 [50.1]  49 [42.6]  2.26, 1 df, P= O.871 
Female  70,982 [49.9]  66 [57.4] 
White  127,723 [89.7]  104 [90.4]  0.55, 3 df, P= O.093 
Black  8,794 [6.2]  7 [6.1] 
Other  1,836 [1.3]  2 [1.7] 
Unknown  3,959 [2.8]  2 [1.7] 
Total  142.312 I1OO.O1  115 [100.01 
11
 Appendix  D:  Proportion  of  DRG  121 billing  errors,  1985  and  1988 
Number  f  standard  1988  1985*  t-test 
error  [percent] 
Hospital  demo~raphv 
1-99 beds  1 [7.1 f  7.1]  8 [30.8 f  9.2]  3.87 
100-299 beds  4 [8.2 f  4.0]  3 [12.0 * 6.6]  0.88 
300+  beds  9 [17.3 t  5.3]  4 [16.0 f  7.5]  0.23 
Metropolitan  10 [11.8 t  3.5]  8 [16.2 f  5.5]  0.87 
Nonmetropolitan  4 [13.3 f  6.3]  7 [6.1 i  1.9]  1.89 
Teaching  7 [16.3 f  5.7]  4 [3.5 ~ 1.6]  2.81 
Nonteaching  7 [9.7 f  3.5]  11 [8.9 t  2.7]  0.22 
Profit  o [0.0 f  0,0]  1 [5.7 * 5.7]  3.50 
Nonprofit  14 [13.2 f  3.3]  14 [18.3 3 4.8]  0.94 
Patient  demography 
<65  years  1 [50.0 t  50.0]  1 [25,0 ~ 25.0]  3.03 
65-74 years  2 [3.8 ~ 2.7]  8 [24.7 ~ 7.6]  4.40 
75-84 years  8 [18.2 t  5.9]  6 [24.0 t  9.5]  0.92 
85+  years  3 [17.6 f  9.5]  o [0.0 f  0.0]  3.80 
Male  3 [6.1 t  3.5]  8 [17.1 ~ 6.0]  2.35 
Female  11 [16.7 t  4.6]  7 [16.0 ~ 6.4]  0.11 
White  11 [10.3 t  3.0] 
Black  3 [42.9 f  20.2] 
Other  o [0.0 *  0.0] 
Unknown  o [0.0 f  0.0] 
Total  14 [12.2 f  3.1]  15 [17.0 f  4.4]  0.92 
*Reweighted  for comparability  to  1988.
12
 Appendix  E  DRG  121 case-mix  index  change,  1985  and  1988 
Relative  weight  ~  1988  1985  Difference  t-test 
standard  error 
Hospital  demo~raphy 
1-99 beds  -0.0227 t  0.0227  -0.2362 t  0.0758  0.2135  4.55 
100-299 beds  -0.0417 t  0.0209  -0.0774 * 0.0434  0.0357  1.40 
300+  beds  -0.1038 ~ 0.0325  -0.0282 t  0.0963  -0.0756  1.53 
Metropolitan  -0.0672 t  0.0207  -0.0673 f  0.0508  0.0001  0.00 
Nonmetropolitan  -0.0681 f  0.0334  -0.0490 f  0.0161  -0.0191  0.89 
Teaching  -0.0962 ~ 0.0345  -0.0061 ~ 0.0210  -0.0901  3.15 
Nonteaching  -0.0503 t  0.0189  -0.0638 t  0.0183  0.0135  0.61 
Profit  0.0000 f  0.0000  -0.0282 f  0.0282  0.0282  3.50 
Nonprofit  -0.0732 i  0.0189  -0.0973 t  0.0470  0.0241  0.57 
patient  demomaphy 
e 65 years  -0.4313 f  0.4313  -0.1803 ~ 0.1803  -0.2510  3.89 
65-74 years  -0.0198 t  0.0138  -0.1275 f  0.0695  0.1077  2.68 
75-84 years  -0.0901 t  0.0301  -0.1750 f  0.0739  0.0849  2.03 
85+  years  -0.1120 f  0.0611  -0.0000 t  0.0000  -0.1120  3.76 
Male  -0.0423 f  0.0244  -0.0516 t  0.0689  0.0093  0.19 
Female  -0.0862 t  0.0246  -0.1271 f  0.0557  0.0409  1.10 
White  -0.0530 f  0.0155 
Black  -0.3215 t  0.1530 
Other  0.0000 * 0.0000 
Unknown  0.0000 t  0.0000 
Total  -0.0675 ~ 0.0175  -0.0845 t  0.0463  0.0170  0.39 
13