Department of Health and Human Services 
OFFICE OF 
INSPECTOR GENERAL 
CHIROPRACTIC CARE 
Comparison of Medicare Managed Care and 
Fee-For-Service 
JUNE GIBBS BROWN 
Inspector General 
JUNE 2000 
OEI-04-97-00495  OFFICE OF INSPECTOR GENERAL 
Public Law 95-452, as amended by Public Law 100-504, mandated the mission of the Office of 
Inspector General (OIG).  That mission is to protect the integrity of the Department of Health and 
Human Services programs as well as the health and welfare of beneficiaries served by them.  This 
statutory mission is carried out through a nationwide program of audits, investigations, 
inspections, sanctions, and fraud alerts.  The Inspector General informs the Secretary of program 
and management problems and recommends legislative, regulatory, and operational approaches to 
correct them. 
Office of Evaluation and Inspections 
The Office of Evaluation and Inspections (OEI) is one of several components of the Office of 
Inspector General.  It conducts short-term management and program evaluations (called 
inspections) that focus on issues of concern to the Department, the Congress, and the public.  The 
inspection reports provide findings and recommendations on the efficiency, vulnerability, and 
effectiveness of departmental programs. 
OEI's Atlanta Regional Office prepared this report under the direction of Jesse J. Flowers, 
Regional Inspector General, and Christopher H. Koehler, Deputy Regional Inspector General. 
Principal OEI staff included: 
Allison Grablowsky, Lead Analyst  Brian Ritchie, Program Analyst

Tricia Davis, Program Specialist  Barbara Tedesco, Mathematical Statistician

Scott Horning, Program Analyst  Joe Townsel, Program Analyst

Graham Rawsthorn, Team Leader

To obtain copies of this report, please call the Atlanta Regional Office at 404-562-7723.  Reports 
are also available on the World Wide Web at our home page address: 
http://www.dhhs.gov/progorg/oei  TABLE  OF  CONTENTS 
PAGE

EXECUTIVE SUMMARY  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1

INTRODUCTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3

FINDINGS

Managed care versus fee-for-service utilization  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Direct access versus physician referral  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Direct access versus fee-for-service  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Chiropractors provided most treatments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Co-payments not limiting access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10

AGENCY COMMENTS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11

APPENDICES

A. Respondent vs. Non-Respondent Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

B.  Summary of Chiropractic Utilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

C. HCFA Comments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
 EXECUTIVE  SUMMARY 
PURPOSE 
To compare chiropractic utilization in Medicare managed care risk plans to that in fee-for-
service. 
BACKGROUND 
We previously completed a report describing policies and practices for providing 
chiropractic services to Medicare beneficiaries in seven managed care organizations  
report number OEI-04-97-00494.  Following issuance of that report, Health Care 
Financing Administration staff requested that we do a national analysis of chiropractic 
utilization in managed care as compared to that in fee-for-service. 
Most Medicare beneficiaries can choose between the Medicare managed care program and 
the fee-for-service program.  Medicare fee-for-service coverage of chiropractic services is 
limited to manual manipulation of the spine to correct a subluxation.  Managed care plans 
offer that service, and can offer other chiropractic services.  However, in this study, 
chiropractic services refers solely to the allowed Medicare benefit of manual 
manipulation of the spine to correct a subluxation. 
We e-mailed a standardized survey to all 310 Medicare managed care risk plans to obtain 
utilization and other data.  We obtained fee-for-service chiropractic utilization data from 
the Health Care Financing Administration  Part B Extract and Summary System, annual 
Data Compendiums, and the National Claims History file.  We did a comparative analysis 
of the managed care and fee-for-service chiropractic utilization data from 1996 through 
1998. 
FINDINGS 
Chiropractic utilization in managed care risk plans was lower than in fee-for-
service.  In 1998, 1.43 percent of beneficiaries in managed care risk plans used 
chiropractic services compared to more than 4 percent of beneficiaries in fee-for-service. 
In the same year, managed care beneficiaries received about seven chiropractic treatments 
per beneficiary compared to approximately nine treatments per beneficiary in fee-for-
service. 
Chiropractic utilization was higher in managed care risk plans when direct access 
was allowed versus primary care physician referral, but it was still lower than in fee-
for-service.  In 1998, 2.14 percent of beneficiaries in managed care risk plans that allowed 
direct access used chiropractic services compared to 1.08 percent of beneficiaries in plans 
that required a physician referral.  Whereas, 4.42 percent of beneficiaries in fee-for-service 
used chiropractic services.  During the same year, beneficiaries in managed 
1 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  care risk plans that required a physician referral received about six treatments per 
beneficiary.  In contrast, beneficiaries in managed care risk plans that allowed direct access 
and beneficiaries in fee-for-service received about nine treatments per beneficiary. 
Chiropractors provided most of the chiropractic treatments to beneficiaries in 
managed care risk plans.  In 1998, chiropractors performed 91 percent of the 
chiropractic treatments in managed care risk plans and 99 percent of the treatments in fee-
for-service. 
Managed care risk plans did not use co-payments to limit beneficiary access to 
chiropractic services.  Of the 244 respondents, 220 plans required a co-payment to 
access chiropractic services.  The co-payments ranged from $3-$27 with the most 
common co-payment being $5.  The chiropractic co-payments were the same as co
payments for other similar services. 
COMMENTS 
The HCFA concurred with our findings and offered several technical comments.  We 
made appropriate revisions.  The full text of their comments is in Appendix C. 
2 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  INTRODUCTION 
PURPOSE 
To compare chiropractic utilization in Medicare managed care risk plans to that in fee-for-
service. 
BACKGROUND 
We recently completed a report describing policies and practices for providing 
chiropractic services to Medicare enrollees in seven managed care organizations.1  That 
report compared chiropractic utilization in the managed care organizations to that in fee-
for-service.  As our report represented a limited sample, the results were not projectable. 
However, following issuance of that report, Health Care Financing Administration staff 
requested that we do a national analysis of chiropractic utilization in managed care as 
compared to that in fee-for-service.  Such a national study would enhance their 
understanding of chiropractic policies and practices in managed care organizations. 
Chiropractic Services in Managed Care and Fee-For-Service 
Most Medicare beneficiaries can choose between Medicare managed care plans, or the 
fee-for-service program.2  Managed care risk plans require beneficiaries to use approved 
plan providers.3  About 5.3 million Medicare beneficiaries were enrolled in managed care 
risk plans in 1998. 
Fee-for-service allows beneficiaries to use any doctor, hospital, or other health care 
provider who accepts Medicare.  About 32.5 million Medicare beneficiaries were enrolled 
in fee-for-service in 1998. 
Medicare fee-for-service and managed care plans are required to provide the chiropractic 
service of manual manipulation of the spine to correct a subluxation.4  In addition, 
managed care plans can offer other chiropractic services.  Beneficiary utilization, however, 
can differ among fee-for-service and managed care plans.  In this study, chiropractic 
services refers solely to the Medicare benefit of manual manipulation of 
1  Chiropractic Services Covered by Medicare Managed Care Organizations (OEI-04-97-00494) 
2  Beneficiaries with end-stage renal disease are not eligible to participate in the managed care program. 
3The managed care risk plans discussed in this report are now known as Medicare+Choice risk plans. The name 
change is due to the Balanced Budget Act of 1997 which established the Medicare+Choice program beginning 1999. 
4  According to the Medicare Carrier Manual, a subluxation is defined as the incomplete dislocation, off centering, 
misalignment, fixation, or abnormal spacing of vertebrae or intervertebral units. 
3 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  the spine to correct a subluxation.  Such chiropractic services can be provided by any 
provider meeting the definition of physician.  The term physician as defined by 
section 1861 of the Social Security Act, includes doctors of medicine, osteopathy, and 
chiropractic. 
Prior Chiropractic Studies 
As part of our continuing study of Medicare and Medicaid issues, we published several 
reports on chiropractic care over the past two years.  For example, in addition to the 
previously mentioned study of seven managed care organizations, we issued reports on 
controls used by Medicare, Medicaid, and other payers, Medicaid coverage of chiropractic 
care, and utilization parameters for chiropractic treatments.  Our website, 
http://www.dhhs.gov/progorg/oei, lists our current reports on chiropractic issues. 
METHODOLOGY 
The Health Care Financing Administration maintains centralized data systems that capture 
utilization data on services provided to Medicare beneficiaries enrolled in fee-for-service. 
However, no such centralized data system exists to capture utilization data for 
beneficiaries enrolled in managed care plans.  Therefore, we developed our own database 
on chiropractic utilization in managed care risk plans. 
To do so, we surveyed all 310 managed care risk plans in April 1999.  We e-mailed a 
standardized data collection instrument to each plan.  As needed, we followed-up on 
incomplete and non-responses.  Ultimately, 244 plans provided self-reported information 
 a 79 percent response rate.  In instances where managed care plans did not respond to 
a particular question, we based our analysis on the number who responded. Where 
applicable, we noted the differences throughout the report. 
Although HCFA did not require managed care plans to capture utilization data for 
chiropractic services, 190 of the 244 respondents claimed to capture such data.  However, 
not all 190 plans provided complete utilization data for each year of our inspection period 
 1996 through 1998.  We defined complete utilization data to include the number of 
beneficiaries enrolled, the number of beneficiaries receiving chiropractic services, and the 
number of treatments received.  For example, 125 plans provided complete 1998 
utilization data.  The 125 plans represented 53 percent of the Medicare enrollees in the 
244 plans that responded. 
The 54 plans (244-190) provided several reasons why they did not capture utilization data. 
The two most common reasons were they 1) paid physicians a set amount to provide 
chiropractic services to their enrolled beneficiaries, i.e. a capitated payment, and 2) had 
few Medicare beneficiaries enrolled. 
We obtained fee-for-service chiropractic utilization data from the Health Care Financing 
Administration.  First, we used Data Compendiums to identify the number of Medicare 
beneficiaries.  Next, we used a 1 percent sample of the National Claims History file to 
estimate the number of beneficiaries using chiropractic services.  The 1 percent sample 
4 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  provided a large number of claims, and a high degree of precision.  Finally, we used the 
Part B Extract and Summary System to determine the number of treatments received by 
beneficiaries and the allowed charges for the treatments.  The specific codes associated 
with the chiropractic service were A2000, 98940, 98941, and 98942. 
We did a comparative analysis of the managed care and fee-for-service chiropractic 
utilization data for 1996 through 1998 as shown in Tables 1 through 6.  In addition, we 
summarized the tables in Appendix B. 
Finally, we conducted non-response analyses.  First, we did an analysis to determine if 
significant differences existed between the 244 plans that responded and the 66 plans that 
did not respond.  We found a significant difference based on the size of the plan, therefore, 
we conducted more detailed analyses.  We based the analyses on whether plans required 
co-payments, and whether a plan allowed direct access or required a physician referral. 
We found no response/non-response bias. 
The second analysis was conducted because all respondents did not provide complete 
utilization data.  Among the 125 plans that provided complete utilization data for 1998, 
we found no bias in plans that conducted or did not conduct utilization reviews.  Appendix 
A shows our non-response analysis in detail. 
____  ____  ____  ____ 
We conducted our inspection between January 1999 and November 1999.  We conducted 
this inspection in accordance with the Quality Standards for Inspections issued by the 
Presidents Council on Integrity and Efficiency. 
5 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  FINDINGS 
Chiropractic utilization in managed care risk plans was lower 
than in fee-for-service, but it has increased 
Beneficiary use 
Beneficiaries in managed care (MC) risk plans used chiropractic services to a lesser extent 
than did those in fee-for-service (FFS).  Table 1, for example, shows that 1.43 percent of 
beneficiaries in managed care risk plans used chiropractic services in 1998.  In contrast, 
more than 4 percent of fee-for-service beneficiaries used chiropractic services. 
Table 1 
Beneficiaries Using Chiropractic Services: Managed Care versus Fee-For-Service 
1996  1997  1998 
57 MC  FFS  99 MC  FFS  125 MC  FFS 
risk plans  risk plans  risk plans 
Number of Medicare  1,532,256  33,509,382  2,224,235  32,933,535  2,767,418  32,545,955 
Beneficiaries 
Beneficiaries using  10,644  1,391,600  26,763  1,405,400  39,669  1,437,200 
chiropractic services 
Percent using  0.69%  4.15%  1.20%  4.27%  1.43%  4.42% 
chiropractic services 
Treatments per beneficiary 
Beneficiaries enrolled in managed care risk plans, on average, received fewer chiropractic 
treatments per beneficiary than did those in fee-for-service.  To illustrate, Table 2 shows 
that managed care beneficiaries received about 7 treatments per beneficiary in 1998. 
Medicare beneficiaries in fee-for-service averaged about 9 chiropractic treatments. 
Table 2 
Chiropractic Treatments Per Beneficiary: Managed Care versus Fee-For-Service 
1996  1997  1998 
57 MC  FFS  99 MC  FFS  125 MC  FFS 
risk plans  risk plans  risk plans 
Beneficiaries using  10,644  1,391,600  26,763  1,405,400  39,669  1,437,200 
chiropractic services 
Number of  70,592  12,274,583  185,820  12,957,421  295,226  13,491,616 
treatments received 
Treatments per  6.63  8.82  6.94  9.22  7.44  9.39 
beneficiary 
6 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  Recent overall increases 
From 1996 through 1998, chiropractic use increased in both managed care risk plans and 
fee-for-service.  However, chiropractic use increased to a greater extent in the managed 
care risk plans.  To illustrate, Table 1 shows that the percent of beneficiaries using 
chiropractic services increased from 0.69 to 1.43 percent in managed care plans.  In fee-
for-service, however, the increase was from 4.15 to 4.42 percent. 
Also, from 1996 through 1998, the average number of treatments per beneficiary 
increased more in managed care than in fee-for-service.  To illustrate, Table 2 shows that 
the number of treatments per beneficiary increased from 6.63 to 7.44 treatments in 
managed care risk plans  an increase of .81 treatments per beneficiary.  In fee-for-
service, the increase was from 8.82 to 9.39  an increase of .57 treatments per 
beneficiary. 
Chiropractic utilization was higher in managed care risk 
plans when direct access was allowed versus primary care 
physician referral 
Beneficiary use 
More beneficiaries used chiropractic services when managed care plans allowed direct 
access than when the plans required a primary care physician referral.  For example, in 
1998, 2.14 percent of beneficiaries enrolled in managed care risk plans that allowed direct 
access used chiropractic services.  Conversely, 1.08 percent of beneficiaries enrolled in 
managed care risk plans that required a primary care physician (PCP) referral used 
chiropractic services. 
Table 3 
Beneficiaries Using Chiropractic Services: Managed Care Direct Access versus 
Primary Care Physician Referral 
1996  57 plans  1997  99 plans  1998  125 plans 
Direct  PCP  Direct  PCP  Direct  PCP 
Access  Referral  Access  Referral  Access  Referral 
(17 plans)  (40 plans)  (35 plans)  (64 plans)  (43 plans)  (82 plans) 
Number of Medicare  522,727  1,009,529  762,904  1,461,331  919,037  1,848,381 
Beneficiaries 
Beneficiaries using  4,444  6,200  12,739  14,024  19,622  20,047 
chiropractic services 
Percent using  0.85%  0.61%  1.67%  0.96%  2.14%  1.08% 
chiropractic services 
7 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  Treatments per beneficiary 
Beneficiaries received more chiropractic treatments, per beneficiary, when managed care 
plans allowed direct access than when the plans required a primary care physician referral. 
To illustrate, in 1998, beneficiaries received, on average, 9 treatments when allowed direct 
access.  However, beneficiaries enrolled in plans requiring a primary care physician 
referral, received about 6 treatments per beneficiary. 
Table 4 
Chiropractic Treatments Per Beneficiary: Managed Care Direct Access versus 
Primary Care Physician Referral 
1996 57 plans  1997 99 plans  1998 125 plans 
Direct  PCP  Direct  PCP  Direct  PCP 
Access  Referral  Access  Referral  Access  Referral 
(17 plans)  (40 plans)  (35 plans)  (64 plans)  (43 plans)  (82 plans) 
Beneficiaries using  4,444  6,200  12,739  14,024  19,622  20,047 
chiropractic services 
Number of  40,684  29,908  106,676  79,144  178,424  116,802 
treatments received 
Treatments per  9.15  4.82  8.37  5.64  9.09  5.83 
beneficiary 
Chiropractic utilization was lower in managed care risk plans 
that allowed direct access than in fee-for-service 
Beneficiary use 
Beneficiaries enrolled in managed care plans that allowed direct access used chiropractic 
services to a lesser extent than did beneficiaries enrolled in fee-for-service.  For example, 
in 1998, 2.14 percent of beneficiaries enrolled in managed care risk plans that allowed 
direct access used chiropractic services.  Conversely, 4.42 percent of beneficiaries enrolled 
in fee-for-service used chiropractic services. 
8 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  Table 5 
Beneficiaries Using Chiropractic Services: Managed Care Direct Access versus 
Fee-For-Service 
1996  1997  1998 
Direct  FFS  Direct  FFS  Direct  FFS 
Access  Access  Access 
(17 plans)  (35 plans)  (43 plans) 
Number of Medicare  522,727  33,509,382  762,904  32,933,535  919,037  32,545,955 
Beneficiaries 
Beneficiaries using  4,444  1,391,600  12,739  1,405,400  19,622  1,437,200 
chiropractic services 
Percent using  0.85%  4.15%  1.67%  4.27%  2.14%  4.42% 
chiropractic services 
Although beneficiary use was less in plans that allowed direct access, the process for 
beneficiaries to obtain chiropractic services was similar to that for beneficiaries in fee-for-
service.  The process allowed beneficiaries to go directly to chiropractors and other 
providers without requiring a physician referral. 
Treatments per beneficiary 
Beneficiaries enrolled in managed care risk plans that allowed direct access received 9.09 
treatments per beneficiary in 1998.  This is comparable to the 9.39 treatments per 
beneficiary in fee-for-service for the same year. 
Table 6 
Chiropractic Treatments Per Beneficiary: Managed Care Direct Access versus Fee-
For-Service 
1996  1997  1998 
Direct  FFS  Direct  FFS  Direct  FFS 
Access  Access  Access 
(17 plans)  (35 plans)  (43 plans) 
Beneficiaries using  4,444  1,391,600  12,739  1,405,400  19,622  1,437,200 
chiropractic services 
Number of  40,684  12,274,583  106,676  12,957,421  178,424  13,491,616 
treatments received 
Treatments per  9.15  8.82  8.37  9.22  9.09  9.39 
beneficiary 
Chiropractors provided most of the chiropractic treatments 
to beneficiaries in managed care risk plans 
All 244 managed care risk plans that responded to our survey provided the chiropractic 
benefit of manual manipulation of the spine to correct a subluxation.  Of the 244 plans, 
9 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  231 used both chiropractors and other providers to perform chiropractic services.  Other 
providers included osteopaths, doctors of medicine, orthopedists, physical therapists, 
physiatrists, and rheumotologists. The remaining 13 plans did not use chiropractors, but 
relied solely on the other providers to perform chiropractic services. 
As mentioned in our methodology, only 125 of the 244 plans provided complete 
utilization data for 1998.  Of the 125 plans, 110 provided their chiropractic utilization data 
by the type of provider who performed the service.  Figure 1 shows that chiropractors 
performed 91.42 percent of the chiropractic treatments in 1998 for the 110 managed care 
risk plans. 
Figure 1 
Percent of Treatments Performed 
by Provider Type in 1998 
M.D. (2.46%) 
OTHER (3.56%)  D.O. (2.56%) 
D.C. (91.42%) 
In contrast, 99.96 percent of chiropractic treatments were performed by chiropractors 
under the fee-for-service program in 1998. 
Managed care risk plans did not use co-payments to limit 
beneficiary access to chiropractic services 
Of the 244 managed care risk plans, 220 required a co-payment for chiropractic services 
and 24 did not.  Of the 220 risk plans, 219 established pre-set co-payment amounts.  The 
co-payments ranged from $3-$27 with the most common co-payment being $5.  The 
remaining plan set the co-payment at 20 percent of the charged amount. 
Chiropractic co-payments in 208 of the 219 plans were the same as co-payments for 
similar services -- primary care physician office visits, physical therapy, or podiatry 
services.  In 10 plans, the co-payment for chiropractic services was $6 higher, on average, 
than such similar services.  The remaining plans chiropractic co-payment was $2 lower 
than such similar services. 
In addition, the chiropractic co-payment in managed care plans was similar to that of fee-
for-service.  The fee-for-service co-payment is 20 percent of allowed charges.  The 
average allowed charge in 1998 was $27.75.  Hence, the average co-payment was $5.55. 
10 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  AGENCY  COMMENTS 
The HCFA concurred with our findings and offered several technical comments.  The full text of 
their comments is in Appendix C. 
In response to HCFA comments, we added a summary table on chiropractic utilization from 1996 
through 1998 in Appendix B.  We further explained that chiropractors and other physicians can 
provide manual manipulation of the spine.  Finally, we clarified that beneficiary utilization of 
chiropractic services can differ among fee-for-service and managed care plans. 
We did not add a comparison of chiropractic utilization of fee-for-service and managed care 
organizations in rural versus urban areas as HCFA suggested.  This was beyond the scope of our 
study.  We also did not make any enrollment comparisons for the entire population of managed 
care plans as HCFA suggested.  As explained in our methodology not all plans responded to our 
survey.  Therefore, we only had enrollment data for the 244 plans that responded. 
11 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  APPENDIX A 
Analysis of Respondents versus Non-Respondents

A consideration in using surveys is whether the results may be biased by significant 
differences between respondents and non-respondents.  To determine if significant 
differences occurred in this survey, we conducted two separate analyses.  The first was an 
analysis of plans that responded to the survey versus plans that did not respond.  The 
second analysis was conducted because all respondents did not provide complete 
utilization data. 
Analysis of respondents vs. non-respondents 
We surveyed all 310 Medicare managed care risk plans in April 1999.  Out of the 310, 244 
plans responded to our survey, while 66 plans did not respond.  The number of enrollees 
as of April 1999 was the only information we had on both the responding and the non-
responding plans.  We ranked the 310 plans based on ascending enrollment size.  We then, 
split the plans into three equal groups  small, medium, and large.  We defined small 
plans as those with 0 to 3,901 enrollees, the medium with 3,902 to 14,985 enrollees, and 
the large with 14,986 or more enrollees.  This analysis is shown in Table 1 below. 
Table 1 
Number of Respondents versus Non-Respondents 
Size of Plan  Number of  Percent of  Number of Non- Percent of Non-
Respondents  Respondents  Respondents  respondents 
Small  75  31%  29  44% 
Medium  79  32%  24  36% 
Large  90  37%  13  20% 
Totals  244  66 
Chi-Square =7.57- Significant at the 95 percent confidence level 
df=2 
Due to the significant chi-square statistic, additional analysis was necessary.  To determine 
whether significant differences existed in this survey, we analyzed co-payment 
requirements, and whether direct access was allowed or a physician referral was required. 
For each of these analyses, we found no relationship based on plan size which suggests 
that no statistical bias was evident. 
A - 1 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  Analysis of utilization data and utilization reviews 
Out of 244 respondents, 125 provided complete utilization data for 1998.  In order to test 
for bias with respect to the utilization data not provided by the remaining 119 plans, we 
performed an analysis on a question where all 244 plans provided a response. 
In the survey, we asked, Do you conduct utilization reviews for manual manipulation of 
the spine?  The Table below shows that out of 244 respondents, 75 plans indicated yes 
they did conduct utilization reviews, and 169 plans indicated no they did not conduct the 
reviews.  We then, broke out the yes and no answers according to whether or not the 
plan provided utilization data.  Table 2 below shows this break down. 
Table 2 
Analysis of Conducting Utilization Reviews by Whether Utilization Data was 
Provided 
Did the plans conduct utilization 
reviews? 
Yes  No  Totals 
Responses from all 244 plans  75 (31%)  169 (69%)  244 
(% of Total) 
Number of plans that provided utilization  52 (42%)  73 (58%)  125 
data (% of Total) 
Number of plans that did not provide  23 (19%)  96 (81%)  119 
utilization data (% of Total) 
Chi-square=14.21- Significant at the 99 percent confidence level 
df=1 
Since the chi-square test was significant, we performed an analysis on plans that provided 
utilization data based on whether or not plans conducted utilization reviews. 
When 125 plans provided utilization data, the difference between conducting or not 
conducting utilization reviews varied by .55 percent.  Approximately 1.72 percent of 
beneficiaries enrolled in plans that conducted utilization reviews, and provided utilization 
data used chiropractic services.  Whereas, 1.17 percent of beneficiaries enrolled in plans 
that did not conduct utilization reviews, and provided utilization data used chiropractic 
services.  This data is shown in Table 3 below. 
Among the 125 plans that provided utilization data, beneficiaries enrolled in plans that 
conducted utilization reviews received about 2.03 treatments more per beneficiary than 
plans that did not conduct utilization reviews.  Table 3 shows that the plans that 
conducted utilization reviews averaged 8.31 treatments per beneficiary.  Whereas, the 
plans that did not conduct utilization reviews averaged 6.28 treatments per beneficiary. 
A - 2 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  Table 3 
Chiropractic Utilization by Plans that Did and Did Not Conduct Utilization 
Reviews 
Conduct  Number of  Small  Medium  Large  # of  # of 
Utilization  1998  Plans  Plans  Plans  beneficiaries  treatments 
Reviews  Enrollees  used service  received 
Yes  1,324,889  13  18  21  22,723  188,782 
10.4%  14.4%  16.8%  1.72%  8.31 
No  1,442,529  18  29  26  16,946  106,444 
14.4%  23.2%  20.8%  1.17%  6.28 
Totals  2,767,418  31  47  47  39,669  295,226 
24.8%  37.6%  37.6%  1.43%  7.44 
A - 3 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  APPENDIX B 
Summary of Chiropractic Utilization:  Managed Care Plans versus Fee-For-Service from 1996 through 1998 
1996  1997  1998 
MC risk plans  FFS  MC risk plans  FFS  MC risk plans  FFS 
PCP  Direct  PCP  Direct  PCP  Direct 
referral  Access  Total  referral  Access  Total  referral  Access  Total 
(40)  (17)  (57)  (64)  (35)  (99)  (82)  (43)  (125) 
# of Medicare  1,009,529  522,727  1,532,256  33,509,382  1,461,331  762,904  2,224,235  32,933,535  1,848,381  919,037  2,767,418  32,545,955 
beneficiaries 
Beneficiaries  6,200  4,444  10,644  1,391,600  14,024  12,739  26,763  1,405,400  20,047  19,622  39,669  1,437,200 
using chiropractic 
services 
% using  0.61%  0.85%  0.69%  4.15%  0.96%  1.67%  1.20%  4.27%  1.08%  2.14%  1.43%  4.42% 
chiropractic 
services 
# of treatments  29,908  40,684  70,592  12,274,583  79,144  106,676  185,820  12,957,421  116,802  178,424  295,226  13,491,616 
received 
Treatments per  4.82  9.15  6.63  8.82  5.64  8.37  6.94  9.22  5.83  9.09  7.44  9.39 
beneficiary 
B - 1 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  APPENDIX C 
C - 1 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  C - 2 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  C - 3 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495  C - 4 
Chiropractic Care: Medicare Managed Care and Fee-For-Service  OEI-04-97-00495