Medicare: Referrals to Physician-Owned Imaging Facilities Warrant HCFA's
Scrutiny (Letter Report, 10/20/94, GAO/HEHS-95-2).
Because Florida had the only statewide information then available on
doctors with a financial stake in imaging center joint ventures, GAO
analyzed 1990 Medicare claims for imaging services ordered by physicians
in that state. GAO found that Florida doctors with a financial interest
in such centers ordered about $10 million more in Medicare-paid imaging
services than other doctors in 1990. Florida physicians with imaging
facilities in their offices, group practices, or other practice settings
also had imaging rates compared with those of other physicians. The
Department of Health and Human Services has not yet finalized the
regulations and procedures needed to implement and enforce federal
self-referral restrictions that would apply to doctors with a financial
interest in joint ventures. Moreover, the Health Care Financing
Administration has no system to check physician-referral patterns to
identify abusive overutilization of self-referrals.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: HEHS-95-2
TITLE: Medicare: Referrals to Physician-Owned Imaging Facilities
Warrant HCFA's Scrutiny
DATE: 10/20/94
SUBJECT: Health care cost control
Medical services rates
Medicare programs
Disease detection or diagnosis
Laboratories
Conflict of interest
Physicians
Medical examinations
Billing procedures
Medical equipment
IDENTIFIER: Florida
Medicaid Program
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Cover
================================================================ COVER
Report to the Chairman, Subcommittee on Health, Committee on Ways and
Means, House of Representatives
October 1994
MEDICARE - REFERRALS TO
PHYSICIAN-OWNED IMAGING FACILITIES
WARRANT HCFA'S SCRUTINY
GAO/HEHS-95-2
Medicare: Physician Referrals
Abbreviations
=============================================================== ABBREV
CPT - Current Procedural Terminology
CT - computed tomography
HCFA - Health Care Financing Administration
HHS - Department of Health and Human Services
MRI - magnetic resonance imaging
OBRA-1993 - Omnibus Budget Reconciliation Act of 1993
UPIN - unique physician identification number
Letter
=============================================================== LETTER
B-253835
October 20, 1994
The Honorable Fortney H. (Pete) Stark
Chairman, Subcommittee on Health
Committee on Ways and Means
House of Representatives
Dear Mr. Chairman:
Imaging services, such as magnetic resonance imaging (MRI), computed
tomography (CT), ultrasound, and X rays, accounted for over $4.6
billion in Medicare Part B allowed charges in 1992. These services
are frequently available outside hospitals at joint-venture imaging
centers, group practices, shared-facility arrangements, and other
settings. Where physicians have a financial interest in the imaging
facility, concerns have been raised about the potential for excessive
use and costs when physicians refer their patients to these
facilities--a practice known as self-referral.
Because of the concerns associated with self-referral, you asked us
to compare the Medicare imaging referral rates of physicians who
invested in joint-venture imaging centers with the referral rates of
other physicians. On April 20, 1993, we testified before the
Subcommittee on Health on the preliminary results of our analyses.\1
Subsequent to our testimony, the Congress included new restrictions
on Medicare and Medicaid self-referrals in the Omnibus Budget
Reconciliation Act of 1993 (OBRA-1993).\2 These new restrictions,
which will become effective January 1, 1995, cover 10 types of
medical services, including diagnostic imaging. OBRA-1993 also
extends Medicare restrictions on clinical laboratory self-referrals,
enacted in 1989, to the Medicaid program. The Medicare and Medicaid
restrictions generally exempt in-office ancillary services and
referrals within group practices, but OBRA-1993 also authorizes the
Secretary of Health and Human Services to establish any additional
regulations needed to protect against program abuse by physicians
using the exemptions to circumvent the self-referral restrictions.
Recently, we provided the Subcommittee with analyses of imaging
referrals within physicians' offices, group practices, and similar
settings where the ordering physician and the imaging provider had
the same Medicare physician or billing identification numbers.\3
Imaging in these settings is generally exempt from the OBRA-1993
self-referral restrictions.
The Congress is now considering legislation that would modify the
OBRA-1993 exemptions for self-referral within group practices and
extend the Medicare and Medicaid self-referral restrictions to all
fee-for-service insurance plans. To assist the Congress as it
considers this legislation, this report consolidates the final
results of our two studies on physician referrals for imaging
services: (1) referrals by physicians with a financial interest in
joint-venture imaging centers, and (2) referrals for imaging provided
within the referring physicians' practice settings.
Our analyses were based on calendar year 1990 Medicare claims for
imaging services ordered by Florida physicians. We used Florida
claims for our analyses because we also had access to information
identifying Florida physicians with a financial interest in imaging
center joint ventures--the only such statewide information then
available. That information was gathered in 1990 by researchers at
Florida State University for the Florida Health Care Cost Containment
Board. Although Florida has a larger Medicare population and more
imaging facilities than some other states, we believe that our
conclusions about the relationship between physician investment in
imaging facilities and their imaging referral rates are generalizable
nationwide because they are based on a large-scale analyses of
physician behavior rather than the characteristics of the patient
population or other demographic variables.
While we did not formally assess the internal controls used by
Florida Blue Cross and Blue Shield or Florida State University to
ensure the accuracy of their data, we performed extensive tests to
evaluate the accuracy of their data and our analyses, as described in
appendix I. We performed our work between April 1993 and July 1994,
in accordance with generally accepted government auditing standards.
Appendix I further describes our scope, data sources, and
methodology, and appendices II and III present detailed information
on imaging referral patterns for each of seven types of imaging
services.
--------------------
\1 Medicare: Physicians Who Invest in Imaging Centers Refer More
Patients for More Costly Services (GAO/T-HRD-93-14, Apr. 20, 1993).
\2 Omnibus Budget Reconciliation Act of 1993, Public Law 103-66,
August 10, 1993.
\3 Medicare Diagnostic Imaging Rates (GAO/HEHS-94-129R, Apr. 5,
1994).
RESULTS IN BRIEF
------------------------------------------------------------ Letter :1
Florida physicians with a financial interest in joint- venture
imaging centers had higher referral rates for almost all types of
imaging services than other Florida physicians. The differences in
the referral rates were greatest for costly high-technology imaging
services. For example, physicians with an interest in imaging
centers that offered MRI services ordered twice as many MRI scans as
other physicians. Medicare costs in Florida would have been about
$10 million less in 1990 if physicians with a financial interest in
joint-venture imaging centers ordered imaging services at the same
rates as other Florida physicians practicing in the same specialties.
Florida physicians with imaging facilities in their offices, group
practices, or other practice settings also had high imaging rates
compared with those of other physicians. Relatively few physicians
provided in-practice MRI or CT services in 1990, but physicians with
access to these services within their practices ordered three times
as many MRI scans and twice as many CT scans for their patients as
other physicians. More significantly, in-practice rates for
ultrasound and echocardiography were 5.1 and 4.8 times higher,
respectively, than rates for physicians who referred patients to
facilities outside their practice settings.
The Department of Health and Human Services (HHS) has not yet
finalized the regulations or procedures needed to implement and
enforce the OBRA-1993 self-referral restrictions as they apply to
physicians with a financial interest in joint ventures. Moreover,
the Health Care Financing Administration (HCFA) and the contractors
that administer the Medicare program have not developed procedures to
systematically monitor physician referral patterns in a way that
would allow them to identify abusive overutilization of medical
services through in-practice self-referrals.
BACKGROUND
------------------------------------------------------------ Letter :2
As we reported in 1992,\4 high Medicare reimbursement rates supported
a proliferation of diagnostic imaging facilities after Medicare began
covering MRI scans in 1985. Few states regulated the establishment
of facilities that provided imaging services outside of hospitals--in
physicians' offices, group practices, or joint-venture imaging
centers--and imaging providers were able to realize profits even in
relatively low-volume settings. These two factors contributed to a
rapid growth in the number of physician-owned imaging facilities.
For example, in 1990, about 24 percent of Florida physicians
practicing in neurological surgery had a financial interest in an MRI
joint venture facility.
Since 1990, Medicare payment levels for many imaging services have
declined as HCFA has phased in the congressionally mandated Medicare
Part B fee schedule. For example, the 1994 Medicare payments for
some MRI and CT procedures are 31 to 32 percent lower than the
payments allowed in 1990. The lower payment levels more closely
reflect the costs of efficient high-volume providers, but they also
create an incentive for physicians with investments in low-volume
imaging facilities to maintain profitability by ordering more
services.
The Congress and some state legislatures have enacted restrictions on
some self-referrals. In 1989 the Congress amended Title XVIII of the
Social Security Act to prohibit the referral of Medicare patients to
clinical laboratories by physicians who have an investment in those
laboratories. In 1992 and 1993, Florida and several other states
enacted measures to more broadly restrict referrals to other
diagnostic and therapeutic medical facilities by physicians with a
financial interest in those facilities. Then, in August 1993, the
Congress included provisions in OBRA-1993 that will extend the
Medicare clinical laboratory self-referral ban to Medicare and
Medicaid payments for 10 additional types of medical services,
including diagnostic imaging.
The OBRA-1993 self-referral restrictions generally do not prohibit
referrals for services that patients obtain within the practice
settings of the referring physician. These in-practice services,
such as X rays and ultrasound services, can increase physician and
patient convenience and allow the ordering physician to supervise the
services. However, limited studies by others\5 have raised concerns
that in-practice investment in expensive imaging equipment is
associated with overutilization of imaging services, similar to the
higher imaging rates associated with self-referral to physician-owned
joint ventures.
Recognizing the potential for using group-practice or shared-facility
arrangements to circumvent the self-referral ban, the 1993 federal
legislation also (1) places some restrictions on in-office ancillary
services; (2) requires billings by a group practice to use the
billing number assigned to the group, thereby facilitating the
identification of services ordered and provided within group
practices; and (3) allows the Secretary of HHS to establish
additional regulations to protect against abusive use of the
exemptions to the self-referral ban. Also, the ability to track
physician referral patterns has been enhanced by the implementation
of unique physician identification numbers (UPIN) and the
requirement, effective January 1, 1992, that all claims for medical
services include the UPIN of the ordering or referring physician.
--------------------
\4 Medicare: Excessive Payments Support the Proliferation of Costly
Technology (GAO/HRD-92-59, May 27, 1992).
\5 Bruce J. Hillman, M.D., and others, "Physician Utilization and
Charges for Outpatient Diagnostic Imaging in a Medicare Population,"
The Journal of the American Medical Association (Oct. 21, 1992), pp.
2050-2054; Stephen E. Radecki, Ph.D, and James P. Steele, M.D.,
"Effect of On-site Facilities on Use of Diagnostic Radiology by
Non-radiologists," Investigative Radiology (Feb. 1990), pp.
190-193.
INVESTORS IN JOINT-VENTURE
IMAGING CENTERS REFER MORE
PATIENTS FOR MORE COSTLY
SERVICES
------------------------------------------------------------ Letter :3
Our analyses of the imaging referral patterns of over 16,000 Florida
physicians show that those physicians with a financial interest in
joint-venture imaging centers ordered more imaging tests and more
costly types of imaging services for their Medicare patients than
other physicians practicing in the same specialty.
Using information from the Florida Health Care Cost Containment Board
and Florida Blue Cross and Blue Shield, we identified 2,395
physicians who had a financial interest in joint-venture imaging
centers and referred Medicare patients for imaging services. We
classified these physicians as owners and compared their imaging
referral rates (imaging services per thousand office visits) to
13,762 other Florida physicians whom we classified as nonowners.\6 We
made separate comparisons for each of seven types of diagnostic
imaging services--MRI scans, CT scans, nuclear medicine scans,
echocardiography, ultrasound services, complex X rays, and simple X
rays.
Because some physician specialties, such as neurology and
orthopedics, make greater use of some types of imaging than other
specialties, we analyzed the differences in referral rates by
physician specialty and computed overall owner-to-nonowner referral
ratios that are adjusted for the number of imaging services ordered
by each specialty.
Overall, owners had higher imaging rates than nonowners for almost
all types of imaging services. Owners ordered 54 percent more MRI
scans; 27 percent more CT scans; 37 percent more nuclear medicine
scans; 27 percent more echocardiograms; 22 percent more ultrasound
services; and 22 percent more complex X rays. The referral rates for
simple X rays were about the same for owners and nonowners. Summary
counts of the physicians, imaging services, and office visits used in
our analyses are provided in appendix II, table II.1. Detailed
referral rates and owner-to-nonowner ratios by physician specialty
are provided in appendix II, tables II.2 and II.3.
We further analyzed the differences in owner and nonowner referral
rates for MRI and CT scans, the two most expensive types of imaging
services. Our analyses show that 952 Florida physicians had a
financial interest in imaging centers that offered MRI services, and
those physicians ordered twice as many MRI scans for their Medicare
patients as nonowners. As shown in figure 1, among the six
specialties that ranked highest in the number of MRI referrals,
owners in all six specialties had higher MRI referral rates than
nonowners, and owners in general practice ordered three times as many
MRI scans as their nonowner counterparts. The detailed referral
rates and MRI owner-to-nonowner ratios by physician specialty are
provided in appendix II, table II.4.
Figure 1: MRI Referrals by MRI
Owners and Nonowners
(See figure in printed
edition.)
Note: These six specialties ranked highest in the number of MRI
referrals, accounting for about 80 percent of the MRI referrals in
our analysis. See appendix II, table II.4.
Similarly, our analyses show that 1,369 Florida physicians had a
financial interest in imaging centers that offered CT services.
Overall, those physicians ordered 29 percent more CT scans for their
Medicare patients than nonowners. As shown in figure 2, owners in
five of the six specialties that ranked highest in the number of CT
referrals had higher CT referral rates than their nonowner
counterparts. The detailed referral rates and CT owner-to-nonowner
ratios by physician specialty are provided in appendix II, table
II.5.
Figure 2: CT Referrals by CT
Owners and Nonowners
(See figure in printed
edition.)
Note: These six specialties ranked highest in the number of CT
referrals, accounting for about 65 percent of the CT referrals in our
analysis. See appendix II, table II.5.
These analyses suggest that self-referral to joint-venture imaging
centers is associated with significant overutilization of imaging
services. We estimate that Medicare costs in Florida would have been
about $10 million less in 1990 if Florida physicians with a financial
interest in joint-venture imaging centers had referred their patients
for imaging services at the same rates as their peers practicing the
same specialties. Furthermore, the Congressional Budget Office
estimated that the OBRA- 1993 restrictions, which generally apply to
these types of self-referrals, will save Medicare $350 million and
Medicaid $37 million over 4 years.
--------------------
\6 As discussed in appendix I, our nonowner category includes some
unidentified Florida physicians known to have a financial interest in
imaging center joint ventures.
PHYSICIANS WITH IN-PRACTICE
IMAGING FACILITIES ORDER MORE
SERVICES THAN PHYSICIANS WHO
REFER TO OTHER FACILITIES
------------------------------------------------------------ Letter :4
Florida physicians with imaging facilities in their offices, group
practices, or other practice affiliations ordered imaging tests much
more frequently than physicians who referred their patients to
imaging facilities outside their practices.
Using claims for imaging services and office visits billed to
Medicare in Florida in 1990, we identified physicians who ordered
imaging services and provided those services themselves or through
other physicians within their practice affiliations. For each type
of imaging service, we classified the ordering physicians as having
in-practice imaging patterns if more than 50 percent of the imaging
services they ordered were provided from within their practice
affiliations. Similarly, we classified physicians as having referral
imaging patterns if more than 50 percent of the imaging services they
ordered were performed at facilities outside their practice
affiliations.
Our analyses of these two groups of physicians by practice specialty
showed that physicians with in-practice imaging patterns had much
higher imaging rates than physicians with referral imaging patterns.
As shown in appendix III, table III.1, the in-practice imaging rates
were about 3 times higher for MRI scans; about 2 times higher for CT
scans; 4.5 to 5.1 times higher for ultrasound, echocardiography, and
diagnostic nuclear medicine imaging; and about 2 times higher for
complex and simple X rays.
Although in-practice imaging is commonplace for some physician
specialties and some types of imaging services, our analyses showed
that in-practice imaging rates were higher than referral imaging
rates for nearly all specialties and imaging services. For example,
echocardiography is used extensively by physicians practicing in
cardiovascular disease. Our analyses showed that 464 cardiovascular
specialists used in-practice echocardiography and 401 referred their
patients to echocardiography facilities outside their practices. As
illustrated in figure 3, the in-practice echocardiography rates were
2.6 times higher than the referral rates for cardiovascular
specialists. Furthermore, the in-practice echocardiography rates for
physicians in internal medicine and general practice exceeded not
only the referral rates of their peers in the same specialties, but
also the referral rates of cardiovascular specialists.
Echocardiography use is of particular importance nationally to the
Medicare program: in terms of allowed charges in 1993, one type of
echocardiogram\7 ranked higher than any other imaging procedure and
ranked 10th among the top 200 Medicare procedures, accounting for
almost $423 million.
Figure 3: Echocardiography
Utilization by Physicians With
In-practice and Referral
Imaging Patterns
(See figure in printed
edition.)
Note: These three specialties ranked highest in the number of
echocardiograms, accounting for about 82 percent of all the
echocardiography services in our analysis. See appendix III, table
III.5.
--------------------
\7 Echocardiography procedure code 93307, complete real time
echocardiography with two dimensional image documentation, with or
without M-mode recording. Over 3.4 million of these echocardiograms
were paid for by Medicare in 1993.
HCFA NEEDS TO MONITOR REFERRAL
PATTERNS TO ENFORCE
SELF-REFERRAL RESTRICTIONS AND
IDENTIFY OVERUTILIZATION
------------------------------------------------------------ Letter :5
Although HHS and HCFA have begun work on the regulations and
reporting requirements needed to implement the OBRA- 1993
self-referral restrictions, HCFA has not implemented a systematic way
to monitor physician referral patterns to identify overutilization
and potentially abusive self-referral practices. The need to
systematically monitor in-practice referrals and trends is
particularly important because the self-referral restrictions imposed
under OBRA- 1993 may provide an incentive to reorganize
physician-owned joint-venture imaging centers into group practices or
shared-facility arrangements exempt from those restrictions.
HCFA and the Medicare contractors are currently using focused medical
review to help identify medical procedures where local utilization
rates are higher than national averages and, therefore, warrant
special prepayment reviews. However, as discussed in our recent
report on HCFA review of claims payments,\8 HCFA and the carriers
have not implemented the type of physician profiling and trend-
analysis reports that would routinely flag questionable referral
practices. HCFA has required the carriers to develop the capability
to perform profiling by ordering and referring physicians and is
testing the use of this information at a small number of carriers.
Since Medicare regulations now require the use of UPIN identifiers,
referring physician numbers, and group practice numbers on Medicare
claims, HCFA and the Medicare carriers have the opportunity to more
closely monitor referral patterns and in-practice imaging
utilization, and to investigate potential overutilization linked to
referral arrangements. High-cost imaging services such as MRI, CT,
diagnostic nuclear medicine, advanced ultrasound services, and
echocardiography warrant particular attention by HCFA.
--------------------
\8 Medicare: Inadequate Review of Claims Payments Limits Ability to
Control Spending (GAO/HEHS-94-42, Apr. 28, 1994).
CONCLUSIONS
------------------------------------------------------------ Letter :6
Physicians with a financial interest in imaging facilities--whether
through investments in joint-venture imaging centers or through
in-practice imaging--order more imaging services for their patients
than do other physicians. The recently enacted Medicare and Medicaid
ban on self-referrals for designated medical services offers the
potential for reducing overutilization of imaging, especially imaging
provided by physician-owned joint ventures. However, physicians who
order and provide these services within their practices may still
have a financial incentive to overutilize the services, especially as
payment levels generally decrease under the Medicare Part B fee
schedule.
The Congress has provided HHS with the tools needed to identify and
restrict self-referrals and overutilization of in-practice imaging
services within the Medicare and Medicaid programs. These tools
include mandatory reporting of physician investment in medical
facilities that provide designated health services, mandatory use of
referring physician identification numbers, and the flexibility to
impose additional restrictions on self-referrals where needed to
prevent abusive practices.
RECOMMENDATIONS TO THE
SECRETARY OF HHS
------------------------------------------------------------ Letter :7
We recommend that the Secretary direct the Administrator of HCFA to
develop the procedures and policy guidance needed for the Medicare
contractors to (1) closely monitor Medicare imaging referral patterns
and utilization rates, (2) assure compliance with the provisions of
the self-referral ban, and (3) identify any overutilization of
imaging services ordered and provided from within physician practice
settings.
We further recommend that the Secretary systematically review imaging
utilization information developed by HCFA and use the authority
provided under OBRA-1993 to develop any additional regulations needed
to reduce overutilization through abusive self-referral practices.
AGENCY COMMENTS
------------------------------------------------------------ Letter :8
HHS commented on a draft of our report and is in general agreement
with our recommendations. See appendix IV for the agency's comments.
---------------------------------------------------------- Letter :8.1
As arranged with your office, unless you publicly announce its
contents earlier, we plan no further distribution of this report
until 30 days after its issue date. At that time, we will send
copies of this report to other appropriate congressional committees,
the Secretary of Health and Human Services, the Administrator of
HCFA, and the Director of the Office of Management and Budget. We
will make additional copies available to other interested parties
upon request.
Please call me on (202) 512-7104 if you or your staff have any
questions about this report. Major contributors are listed in
appendix V.
Sincerely yours,
Leslie G. Aronovitz
Associate Director,
Health Financing Issues
SCOPE, DATA SOURCES, AND
METHODOLOGY
=========================================================== Appendix I
This appendix describes (1) our scope and data sources, (2) our
methodology for identifying and analyzing referrals by physicians
with a financial interest in joint-venture imaging centers, and (3)
our methodology for identifying and analyzing referrals for imaging
provided within the referring physicians' practice settings.
SCOPE AND DATA SOURCES
--------------------------------------------------------- Appendix I:1
Several studies have investigated the effect of physician ownership
on the utilization and cost of health care services,\9 but those
studies have based their findings on analysis of relatively small
physician and patient populations. In contrast, our study is a
large-scale analysis of physician referral patterns for all types of
diagnostic imaging services. The study population includes all
Florida physicians who referred Medicare patients for outpatient\10
imaging services in 1990, and our data sources include the full
Florida Medicare Part B Beneficiary History File for calendar year
1990 and the Florida Medicare Provider File, both obtained from
Florida Blue Cross and Blue Shield. By selecting Florida for our
study we were also able to make use of the extensive data on
physician ownership of Florida medical facilities compiled for the
Florida Health Care Cost Containment Board by Florida State
University.\11
While we did not formally assess the internal controls used by
Florida Blue Cross and Blue Shield or Florida State University to
ensure the accuracy of their data, we met extensively with the
officials who were responsible for collecting and maintaining these
data and reviewed their methodology and documentation. We also
performed detailed tests and edits on computerized claims and
manually reviewed printouts of beneficiary history records to trace
individual imaging services to imaging providers and referring
physicians. To further evaluate the accuracy of our data and
analyses, we reviewed medical and claims records from five diagnostic
imaging centers in Florida. We also met with HCFA staff and other
researchers who have studied physician referral patterns to obtain
their technical and methodological suggestions.
Given the size of our final database--almost 2.5 million imaging
services ordered by about 17,900 physicians--we did not attempt to
assess the medical necessity of the imaging services ordered.
Because our study is based on the full range of diagnostic imaging
services ordered by physicians in a wide variety of primary care and
specialty practices and includes a large patient population, we
believe our study design minimizes the influence of individual
patient and physician characteristics on the overall analytical
results. Furthermore, we structured our analyses for each type of
imaging service so that they are based on comparisons between
physicians practicing in the same specialty. Thus, our analytical
approach reflects the variation in the use of different types of
imaging by physicians practicing in different specialties.
--------------------
\9 See, for example, Bruce J. Hillman, M.D., and others,
"Physicians' Utilization and Charges for Outpatient Diagnostic
Imaging in a Medicare Population," Journal of the American Medical
Association, Vol. 268, No.15 (Oct. 21, 1992), pp. 2050-2054;
Stephen E. Radiecki and James P. Steele, "Effect of On-site
Facilities on Use of Diagnostic Radiology by Non-radiologists,"
Investigative Radiology (Feb. 1990), pp. 190-193; Alex Swedlow and
others, "Increased Costs and Rates of Use in the California Workers'
Compensation System as a Result of Self Referral by Physicians," New
England Journal of Medicine, Vol. 327, No. 21 (Nov. 19, 1992), pp.
1502-1524.
\10 We use "outpatient" to describe all provider settings other than
hospital inpatient facilities--including freestanding imaging
facilities and physicians' offices, as well as hospital outpatient
departments.
\11 Joint Ventures Among Health Care Providers in Florida, State of
Florida Health Care Cost Containment Board (Sept. 1991).
ANALYSIS OF REFERRED IMAGING
SERVICES BY PHYSICIAN OWNERS
AND NONOWNERS
--------------------------------------------------------- Appendix I:2
The first phase of our study includes only imaging services provided
by facilities outside the referring physicians' practice settings, in
facilities such as hospital outpatient departments and freestanding
(nonhospital) imaging centers. For these analyses we grouped the
referring physicians into owner and nonowner categories based on
whether or not they had a financial interest in a freestanding
joint-venture imaging center.
IDENTIFYING PHYSICIANS WITH
OWNERSHIP INTERESTS IN
FREESTANDING IMAGING CENTERS
------------------------------------------------------- Appendix I:2.1
We identified physician owners of Florida imaging facilities using
survey information gathered by Florida State University for the
Florida Health Care Cost Containment Board during 1990. Florida
State researchers sent surveys to all freestanding facilities
providing diagnostic imaging services, and the facilities were asked
to identify their physician owners, if any. Of the 220 freestanding
diagnostic imaging centers in Florida in 1990, 177-- about 80
percent--responded to the survey.\12
After meeting with the principal researchers and reviewing the survey
responses, we matched ownership information from the surveys with
physician data from Florida Blue Cross and Blue Shield's Medicare
Provider File to identify the Medicare provider number(s) for each
physician owner. We identified the Medicare provider numbers for
2,993 physician owners. Our ownership category excludes an unknown
number of additional physicians with a financial interest in imaging
centers because (1) some medical facilities did not respond to the
Florida State survey, (2) some responding facilities indicated that
there were physicians with a financial interest in their facilities
but declined to identify those physicians, and (3) some survey
responses did not contain enough information for us to confidently
match their names to a physician in the Medicare Provider File. Our
nonowner category includes all Florida physicians not identified as
owners. Assuming that the unidentified physician owners, included in
the nonowner category, also had the higher imaging referral rates
associated with owners, our analyses understate the magnitude of the
higher imaging referral rates of physician owners.
After preliminary analyses of our databases and consultations with
medical professionals, we excluded physicians practicing in
radiology, pathology, and anesthesiology from both our owner and
nonowner groups, because physicians in those specialties generally do
not refer patients for imaging services.
For some of our analyses we also determined which of the physician
owners had a financial interest in joint-venture imaging centers that
provided MRI services, CT services, or both. We identified these
physicians from information in the surveys from Florida State
University, the Florida Medicare Part B Provider File, and Medicare
claims submitted by imaging providers. We could not identify the
types of services provided by 87 of the physician-owned imaging
facilities; therefore, our analyses underestimate the numbers of
physicians who invested in facilities providing MRI services, CT
services, or both.
--------------------
\12 Florida State University researchers provided us with 17 surveys
that they received too late to include in their September 1991
report.
CREATING OUR DATA SET OF
IMAGING SERVICES AND OFFICE
VISITS
------------------------------------------------------- Appendix I:2.2
The Beneficiary History File that we obtained from Florida Blue Cross
and Blue Shield included over 50 million claims with information on
all Medicare Part B services provided in Florida between November
1989 and March 1991. As further described below, using this database
we extracted paid claims with no obvious errors or inconsistencies
for outpatient imaging services and office visits provided in 1990.
We used these data to calculate physicians' imaging referral
rates--the number of imaging services ordered per 1,000 office
visits. This is a measure we have used in previous work on physician
referrals for diagnostic services.\13
We identified claims for imaging services and office visits using the
American Medical Association's 1990 Current Procedural Terminology
(CPT) manual, HCFA's 1990 procedure code listings, and guidance from
a physician consultant. We classified all diagnostic imaging
services into seven categories designed to group similar procedures
together: MRI, CT, ultrasound, echocardiography, diagnostic nuclear
medicine, complex X rays, and simple X rays.
In deciding which CPT codes to include as office visits, we
considered all physician-patient encounters that provide physicians
an opportunity to refer their patients for imaging services and an
opportunity for physician-patient choice of imaging facility.
Because hospital inpatients generally do not have an opportunity for
physician-patient choice of imaging facility, we excluded all
hospital inpatient visits and inpatient imaging services from our
analysis, regardless of the CPT codes used for those services. For
office visits we included all CPT and HCFA codes for outpatient
medical services, consultations, preventive medicine, and case
management. We also selectively included other CPT codes for
services such as psychiatry, ophthalmology, and critical care.
This selection process yielded a database with about 3.5 million
imaging services and 19.4 million office visits.
--------------------
\13 Medicare: Referring Physician's Ownership of Laboratories and
Imaging Centers (GAO/T-HRD-89-26, June 8, 1989).
IDENTIFYING THE PHYSICIANS
WHO ORDERED THE IMAGING
SERVICES
------------------------------------------------------- Appendix I:2.3
In 1990, providers of imaging services were not required to include
the referring physicians' Medicare numbers on their claims for the
imaging services. Some claims identified the referring physician but
others did not. In our database of about 3.5 million imaging
services (which included in-practice imaging), the Medicare claims
for about 41 percent of those imaging services included the referring
physician number. After analyzing a sample of the claims in our
database and consulting with other researchers, we developed and
tested various approaches for identifying the physician who ordered
the imaging service from information in the beneficiary history file.
We did a detailed analysis of a sample of the claims that included
the referring physician number, and we traced some of those claims to
medical records at selected imaging providers. We found that the
inclusion or exclusion of the referring physician in the claims
database appeared random; that is, it did not follow any particular
pattern that would bias our analytical results. We also found cases
in which the referring physician was identified on a hard copy of the
claim but this information was not transcribed by Florida Blue Cross
and Blue Shield into the claims database.
Using claims that identified the ordering physician, we simulated
various approaches for identifying the ordering physician when that
physician was not identified. We determined that an imaging service
for a beneficiary could be reasonably matched to the physician who
ordered the service if the beneficiary had an office visit with that
physician within a "referral window" occurring from 21 days before to
7 days after the imaging service.\14
For those claims that identified the ordering physician, we included
that imaging service and ordering physician in our analysis if the
patient had an office visit with that physician within the referral
window, regardless of the number of office visits with other
physicians also within the referral window. We excluded claims where
the identified ordering physician did not have any office visits with
the patient within the referral window because in tracing those cases
to beneficiary history records and medical files we found there was a
likelihood that the claim did not correctly identify the ordering
physician.
For those imaging claims where there was more than one potential
ordering physician within the referral window, we further tested
various approaches for identifying which physician ordered the
imaging service. For example, we simulated selecting the physician
with the closest office visit to the imaging service as the ordering
physician, and we compared the result to information in medical
files. Although the overall error rate from that approach was
relatively low, we believed that there was a possibility that the
approach could introduce bias by overstating in-practice imaging
rates, especially in cases where there was an office visit and an
imaging service on the same day. Therefore, where there was only one
potential ordering physician within the referral window, we
considered that physician the ordering physician and included that
imaging service in our analyses. Where the imaging claim did not
identify the ordering physician and there were multiple potential
ordering physicians within the referral window we excluded that
imaging service from our analyses.
This methodology excluded about 1 million imaging services from our
database of about 3.5 million imaging referrals. Excluding those
imaging services generally understates the physicians' imaging rates,
but after studying the excluded imaging services we concluded that
there was no evident pattern that would introduce bias into our
analytical results.
--------------------
\14 Physicians sometimes refer a patient for an imaging service (for
example, an X ray) shortly before the physician sees the patient.
Thus, an imaging service can occur before the office visit with the
physician who ordered the service.
VERIFYING THE ACCURACY OF
OUR REFERRAL LOGIC
------------------------------------------------------- Appendix I:2.4
To test the accuracy of our methodology for identifying the ordering
physician, we reviewed medical and billing records for about 100
imaging services from each of five Florida imaging centers. Based on
this review, we estimate that our computerized procedures correctly
identified the ordering physician for 89 percent of the imaging
services used in our analyses. To further confirm the accuracy of
our computerized procedures and programming, we extracted over 1,300
beneficiary claim histories and provider billing records from our
database and manually verified the match between the imaging service
and the ordering physician.
For those cases where our referral logic may have identified an
incorrect referring physician, we believe that there was little or no
impact on our analytical results. The large scale of our study
ensured that the incorrect attribution of a relatively small number
of imaging referrals would be distributed over a large number of
physicians across all our comparison groups. Also, we analyzed the
claims for the services in which we discovered attribution errors,
and we found no evidence of a pattern that would bias our analytical
results.
ANALYZING OWNER AND NONOWNER
IMAGING REFERRAL PATTERNS
------------------------------------------------------- Appendix I:2.5
Of the 2.5 million imaging services for which we identified the
ordering physician, we determined that about 1.2 million of those
imaging services were provided within the ordering physicians'
practice settings, as described below in a separate section of this
appendix. The remaining 1.3 million imaging services were from
referrals to facilities outside the ordering physicians' practice
settings and were included in our analysis of owner and nonowner
referral rates.
We arrayed and analyzed these data by type of imaging procedure and
physician specialty, as shown in appendix II, tables II.2 and II.3.
As specified in the notes to those tables, we used cutoff criteria
for physician specialties where there was limited use of imaging.
For each type of imaging service we also computed a weighted summary
ratio of the referral rates of owners and nonowners, weighting by the
number of imaging referrals made by each physician specialty to
account for the variation in the use of imaging--by both owners and
nonowners--among the various physician specialties. The overall
summary of this analysis is provided in appendix II, table II.1.
To determine if physicians with a financial interest in facilities
that provide costly high-technology services are more likely to refer
Medicare beneficiaries for those services than owners in general, we
analyzed referral rates for two additional physician groupings: one
for physicians with a financial interest in facilities providing MRI
scans and another for physicians with a financial interest in
facilities providing CT scans. The detailed results of those
analyses are provided in appendix II, tables II.4 and II.5.
ANALYSIS OF IN-PRACTICE IMAGING
--------------------------------------------------------- Appendix I:3
The second phase of our study includes the 1.2 million in-practice
imaging services provided by imaging facilities within the ordering
physicians' practice settings as well as the 1.3 million imaging
services provided outside the referring physicians' practice
settings, in facilities such as hospital outpatient departments and
freestanding imaging centers.
IDENTIFYING IN-PRACTICE
IMAGING SERVICES
------------------------------------------------------- Appendix I:3.1
We classified an imaging service as in-practice if the patient
received the service from either (1) the physician who ordered the
service, (2) a physician in the same group practice as the ordering
physician, or (3) an entity (such as an imaging center or neurology
clinic) with which the ordering physician had a practice affiliation.
To identify in-practice imaging we used computerized procedures to
compare the Medicare billing and performing provider numbers on the
imaging claim to those on the ordering physician's office visit
claim. If either of the numbers on the imaging claim matched either
of the numbers on the office visit claim, we classified the imaging
service as in-practice; that is, the imaging service was provided by
the ordering physician or by a physician or entity (such as a clinic
or group practice) with which the ordering physician had a practice
affiliation.
CLASSIFYING PHYSICIANS BASED
ON IMAGING PATTERNS
------------------------------------------------------- Appendix I:3.2
For each physician who ordered imaging services, we classified his or
her predominant imaging pattern as either in-practice or referral
separately for each of the seven types of imaging services. For
example, if more than 50 percent of the ultrasound services ordered
by a physician were in-practice, we classified that physician's
ultrasound imaging pattern as in-practice. Similarly, if more than
50 percent of the MRI scans ordered by that same physician were
referral, we classified that physician's MRI imaging pattern as
referral. Thus, the same physician may be classified as having a
referral imaging pattern for one type of service and an in-practice
imaging pattern for another type of service.
ANALYZING OVERALL IMAGING
UTILIZATION
------------------------------------------------------- Appendix I:3.3
Once we classified physicians based on their imaging pattern
(in-practice or referral) for each type of imaging service, we
arrayed and analyzed these data by type of imaging procedure and
physician specialty (see app. III, tables III.2 through III.8). As
specified in the notes to those tables, we used cutoff criteria for
physician specialties where there was limited use of imaging. For
each type of imaging service we also computed a weighted summary
ratio of the in-practice and referral imaging rates, weighting by the
number of imaging referrals made by each physician specialty. The
overall summary of this analysis is provided in appendix III, table
III.1.
LIMITATIONS OF OUR
IN-PRACTICE ANALYSIS
------------------------------------------------------- Appendix I:3.4
Because our data are from 1990, they predate full implementation of
the unique physician identification number (UPIN) and the OBRA-1993
requirement that physicians in group practices bill under their group
practice numbers rather than their individual numbers. Thus, in our
database the Medicare numbers on office visit and imaging claims
could have been those of the performing physician even though the
service was provided in a group practice. Therefore, our analyses
cannot distinguish between the various types of in-practice imaging
arrangements (for example, solo practices, multi-specialty group
practices, and shared-facility arrangements).
Also, because physicians may have used different Medicare numbers on
their office visit and imaging claims, even though both services were
provided by the same physician or group practice, our analyses
probably underestimate the number of in-practice imaging services and
the number of physicians with in-practice imaging patterns. Thus,
the magnitude of the higher in-practice imaging rates revealed in our
analyses is probably a conservative estimate, assuming that some
physicians with in-practice imaging patterns are grouped with the
physicians with referral imaging patterns, and that those physicians
also had the higher imaging rates associated with in-practice
imaging.
IMAGING CENTER OWNER AND NONOWNER
IMAGING RATES
========================================================== Appendix II
The tables in this appendix provide detailed comparisons between the
imaging referral rates of Florida physicians with a financial
interest in joint-venture imaging centers (referred to as owners) and
all other Florida physicians (referred to as nonowners). As
described in appendix I, we did not have sufficient information to
identify some of the physician owners and the unidentified owners are
included in our analyses as nonowners. This would tend to understate
the higher referral rates associated with the physician owners,
assuming that the unidentified owners had referral rates similar to
the identified owners. Notes to the tables provide information on
the cutoff criteria for the physician specialties and imaging
referral rates included in the tables.
Table II.1 provides a summary of the physician, imaging service, and
office visit counts for owners and nonowners, by type of imaging
service. This table also provides summary ratios of the
owner-to-nonowner referral rates, weighted by the number of referrals
by each physician specialty to adjust for variations in imaging use
among physician specialties. Tables II.2 and II.3 provide detailed
information for all referrals by physician specialty.
This appendix also provides referral rates and ratios for two subsets
of physician owners--those with a financial interest in imaging
centers that offer MRIs, CTs, or both services. Table II.4 provides
MRI referral rates by specialty for owners and nonowners of imaging
centers providing MRI services. The summary ratio shows that MRI
owners referred twice as often for MRI scans as nonowners.
Similarly, table II.5 provides CT referral rates by specialty for
owners and nonowners of imaging centers providing CT services. The
summary ratio shows that CT owners referred their patients for CT
scans 29 percent more often than nonowners.
Table II.1
Summary of Physician, Imaging Service,
and Office Visit Counts, by Type of
Imaging Service for Referred Imaging
Services
Ratio of
owner-to-
nonowner
referral
Type of service Owners Nonowners Total Owners Nonowners Total Owners Nonowners Total rates\a
------------------ -------- ------------- ------------- -------- ------------ ---------- ---------- ------------ ----------- --------------
MRI 2,122 11,697 13,819 11,650 22,099 33,749 2,258,613 9,769,738 12,028,351 1.54
CT 2,347 12,391 14,738 30,800 83,315 114,115 2,302,365 9,816,887 12,119,252 1.27
Ultrasound 2,106 12,332 14,438 24,204 75,961 100,165 2,176,944 10,263,263 12,440,207 1.22
Echocardiography 1,673 11,164 12,837 13,550 40,831 54,381 1,982,142 9,932,889 11,915,031 1.27
Nuclear medicine 2,129 12,091 14,220 20,060 48,753 68,813 2,272,806 10,513,993 12,786,799 1.37
Complex X ray 2,265 11,375 13,640 29,024 88,273 117,297 2,190,622 8,189,197 10,379,819 1.22
Simple X ray 2,285 12,858 15,143 146,359 600,493 746,852 2,304,395 10,648,918 12,953,313 1.04
-----------------------------------------------------------------------------------------------------------------------------------------------------
Note: For each type of imaging service (for example, MRI or CT) this
summary excludes physicians, imaging services and office visits for
physician specialties where (1) the physicians in that specialty
accounted for less than 0.5 percent of the total imaging services
ordered for that type of imaging or (2) there were no physicians in
either the owner or nonowner categories. After applying this cutoff
criteria, this summary includes about 1.23 million referred imaging
services, or about 96 percent of the 1.28 million referred imaging
services in our database.
\a The ratios of owner-to-nonowner referral rates are weighted by
physician specialty. For each type of imaging service (for example,
MRI or CT), the weighting factor for each specialty is the number of
the total imaging services of that type that were ordered by the
physicians in that specialty. We computed weighted ratios to adjust
for differences in the use of imaging among physician specialties.
Table II.2
Imaging Referrals per Thousand Office
Visits, by Referring Physician Specialty
and Ownership Status
Number
Referring of
physician Ownership physicia Number of MRI CT Nuclear Complex X Simple X
specialty status ns office visits scans scans medicine Echocardiography Ultrasound rays rays
------------------ ------------- -------- ------------- ------ ------ -------------- ----------------- ---------- ------------ ------------
Cardiovascular Owner 159 206,579 1.31 9.46 14.98 14.12 11.16 10.54 49.81
disease
Nonowner 706 554,691 0.80 5.79 12.39 12.80 7.05 7.37 48.69
Endocrinology Owner 19 14,074 \a 8.88 4.69 1.07 3.98 4.48 167.83
Nonowner 326 184,882 \a 11.81 2.89 2.44 3.95 5.38 206.14
Family practice Owner 229 380,872 1.97 8.54 4.65 5.32 9.22 12.63 67.14
Nonowner 1,681 1,508,811 1.39 6.56 3.01 4.32 8.50 9.61 66.36
Gastroenterology Owner 71 61,301 1.76 25.90 8.42 4.98 25.38 31.16 60.70
Nonowner 278 136,750 0.72 28.98 6.49 2.12 21.83 35.96 49.85
General practice Owner 185 219,725 1.84 7.70 3.85 4.52 8.35 9.73 78.84
Nonowner 1,960 1,629,224 0.85 5.80 2.58 4.88 7.64 7.72 75.29
General surgery Owner 138 41,950 4.46 22.05 10.51 1.53 18.16 34.28 127.37
Nonowner 921 304,775 0.92 13.09 5.63 3.47 11.80 21.00 94.83
Geriatrics Owner 5 12,319 \a \a \a \a \a \a 108.21
Nonowner 19 37,367 \a \a \a \a \a \a 107.80
Gynecology Owner 7 1,564 \a \a \a \a 9.59 \a \a
(osteopath)
Nonowner 62 14,477 \a \a \a \a 36.33 \a \a
Internal medicine Owner 476 640,063 2.31 12.05 8.03 9.38 11.30 13.29 70.62
Nonowner 2,364 2,290,218 1.81 9.47 5.78 6.01 9.28 10.70 67.49
Maxillofacial Owner 78 106,359 6.03 45.86 20.91 2.59 5.99 6.07 82.21
surgery
Nonowner 212 223,346 4.30 37.49 16.78 1.39 4.62 5.87 74.98
Nephrology Owner 30 23,130 4.02 12.54 15.39 11.59 24.60 12.58 96.24
Nonowner 95 51,949 1.92 7.51 10.51 3.41 14.86 8.93 69.68
Neurological Owner 64 13,943 66.99 54.36 18.65 \a \a 19.22 \a
surgery
Nonowner 108 18,490 53.22 42.73 10.76 \a \a 19.20 \a
Neurology Owner 134 72,604 47.09 23.86 4.77 2.26 \a 3.33 31.00
Nonowner 259 122,395 38.18 23.47 3.64 2.25 \a 3.19 37.02
Neuropsychiatry Owner 20 43,150 5.56 5.28 5.93 1.67 3.29 4.17 26.79
Nonowner 106 168,941 4.90 5.01 5.89 2.39 4.00 3.10 57.19
Obstetrics/ Owner 215 33,213 \a 6.47 \a \a 24.75 7.05 106.68
gynecology
Nonowner 856 116,048 \a 6.26 \a \a 22.10 6.21 102.72
Oncology/ Owner 2 2,982 \a 107.98 \a \a \a \a \a
hematology
Nonowner 24 21,522 \a 22.63 \a \a \a \a \a
Ophthalmology Owner 38 65,165 1.30 0.60 0.41 0.34 2.26 \a 8.73
Nonowner 775 1,380,109 0.36 0.75 0.38 0.50 1.03 \a 9.76
Orthopedic surgery Owner 238 127,820 16.88 9.75 12.84 \a 1.24 4.83 38.09
Nonowner 656 295,546 13.01 7.57 10.35 \a 1.28 4.44 41.47
Otolaryngology Owner 47 44,092 7.17 13.06 1.59 \a \a \a 29.44
Nonowner 310 240,370 4.10 11.91 1.27 \a \a \a 29.75
Podiatry Owner 6 7,870 \a \a 2.16 0.64 1.40 \a 28.34
Nonowner 615 844,265 \a \a 0.48 0.56 1.04 \a 8.23
Preventive Owner 18 29,445 3.67 9.17 9.10 4.69 9.75 7.68 45.58
medicine
Nonowner 106 97,486 1.83 6.49 5.29 3.37 8.54 7.33 48.22
Psychiatry Owner 18 7,751 5.03 \a \a 0.39 \a \a \a
Nonowner 547 284,892 0.60 \a \a 1.14 \a \a \a
Pulmonary disease Owner 54 62,104 2.58 17.52 7.97 4.43 5.27 8.61 71.88
Nonowner 213 150,155 1.01 15.81 7.53 4.76 5.03 6.42 93.72
Thoracic surgery Owner 12 1,730 \a \a \a \a \a 26.59 \a
Nonowner 128 23,900 \a \a \a \a \a 32.76 \a
Urology Owner 125 112,560 2.29 16.56 19.78 \a 34.02 41.69 40.25
Nonowner 400 311,590 0.87 14.10 15.70 \a 26.86 40.91 42.38
-----------------------------------------------------------------------------------------------------------------------------------------------------
\a For each type of imaging service (for example, MRI or CT), this
analysis excludes imaging referral rates where (1) either owners or
nonowners within a specialty made no referrals or (2) the referrals
by physicians in the specialty for owners and nonowners combined
accounted for less than 0.5 percent of all the referrals for that
type of imaging service. The referrals included in this analysis
account for 97 percent of the MRI scans we matched to a referring
physician, 96 percent of the CT scans; 97 percent of the nuclear
medicine scans; 97 percent of the echocardiography services; 97
percent of the ultrasound services; 97 percent of the complex X rays;
and 96 percent of the simple X rays.
Table II.3
Ratio of Owner-to-Nonowner Referral
Rates, by Referring Physician Specialty
Number
Referring of
physician Ownership physicia Number of MRI CT Nuclear Complex X Simple X
specialty status ns office visits scans scans medicine Echocardiography Ultrasound rays rays
------------------ ------------- -------- ------------- ------ ------ -------------- ----------------- ---------- ------------ ------------
Cardiovascular Owner 159 206,579 1.63 1.63 1.21 1.10 1.58 1.43 1.02
disease
Nonowner 706 554,691
Endocrinology Owner 19 14,074 \a 0.75 1.62 0.44 1.01 0.83 0.81
Nonowner 326 184,882
Family practice Owner 229 380,872 1.42 1.30 1.54 1.23 1.08 1.31 1.01
Nonowner 1,681 1,508,811
Gastroenterology Owner 71 61,301 2.46 0.89 1.30 2.35 1.16 0.87 1.22
Nonowner 278 136,750
General practice Owner 185 219,725 2.17 1.33 1.49 0.93 1.09 1.26 1.05
Nonowner 1,960 1,629,224
General surgery Owner 138 41,950 4.87 1.68 1.87 0.44 1.54 1.63 1.34
Nonowner 921 304,775
Geriatrics Owner 5 12,319 \a \a \a \a \a \a 1.00
Nonowner 19 37,367
Gynecology Owner 7 1,564 \a \a \a \a 0.26 \a \a
(osteopath)
Nonowner 62 14,477
Internal medicine Owner 476 640,063 1.27 1.27 1.39 1.56 1.22 1.24 1.05
Nonowner 2,364 2,290,218
Maxillofacial Owner 78 106,359 1.40 1.22 1.25 1.86 1.30 1.03 1.10
surgery
Nonowner 212 223,346
Nephrology Owner 30 23,130 2.09 1.67 1.46 3.40 1.66 1.41 1.38
Nonowner 95 51,949
Neurological Owner 64 13,943 1.26 1.27 1.73 \a \a 1.00 \a
surgery
Nonowner 108 18,490
Neurology Owner 134 72,604 1.23 1.02 1.31 1.01 \a 1.05 0.84
Nonowner 259 122,395
Neuropsychiatry Owner 20 43,150 1.13 1.05 1.01 0.70 0.82 1.34 0.47
Nonowner 106 168,941
Obstetrics/ Owner 215 33,213 \a 1.03 \a \a 1.12 1.13 1.04
gynecology
Nonowner 856 116,048
Oncology/ Owner 2 2,982 \a 4.77 \a \a \a \a \a
hematology
Nonowner 24 21,522
Ophthalmology Owner 38 65,165 3.62 0.80 1.09 0.67 2.18 \a 0.89
Nonowner 775 1,380,109
Orthopedic surgery Owner 238 127,820 1.30 1.29 1.24 \a 0.97 1.09 0.92
Nonowner 656 295,546
Otolaryngology Owner 47 44,092 1.75 1.10 1.25 \a \a \a 0.99
Nonowner 310 240,370
Podiatry Owner 6 7,870 \a \a 4.54 1.14 1.34 \a 3.44
Nonowner 615 844,265
Preventive Owner 18 29,445 2.01 1.41 1.72 1.39 1.14 1.05 0.95
medicine
Nonowner 106 97,486
Psychiatry Owner 18 7,751 8.38 \a \a 0.34 \a \a \a
Nonowner 547 284,892
Pulmonary disease Owner 54 62,104 2.56 1.11 1.06 0.93 1.05 1.34 0.77
Nonowner 213 150,155
Thoracic surgery Owner 12 1,730 \a \a \a \a \a 0.81 \a
Nonowner 128 23,900
Urology Owner 125 112,560 2.63 1.17 1.26 \a 1.27 1.02 0.95
Nonowner 400 311,590
All listed Owner 2,388 2,332,365 1.54\b 1.27\b 1.37\b 1.27\b 1.22\b 1.22\b 1.04\b
specialties
Nonowner 13,727 11,012,199
-----------------------------------------------------------------------------------------------------------------------------------------------------
\a For each type of imaging service (for example, MRI or CT), this
analysis excludes imaging referrals where (1) either owners or
nonowners within a specialty made no referrals or (2) the referrals
by physicians in the specialty for owners and nonowners combined
accounted for less than 0.5 percent of all the referrals for that
type of imaging service.
\b The ratios of owner-to-nonowner referrals for all specialties
combined are weighted ratios, based on the number of each type of
imaging service referrals by each specialty.
Table II.4
MRI Referrals, by Referring Physician
Specialty and MRI Ownership Status
MRI
Number referrals Ratio of MRI
Referring of Number of per 1,000 owner-to-
physician MRI ownership physicia office office nonowner referral
specialty status ns visits visits rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular Owner 61 69,952 1.63 1.98
disease
Nonowner 777 650,302 0.82
Family practice Owner 56 80,827 2.07 1.40
Nonowner 1,831 1,766,487 1.48
Gastroenterology Owner 29 29,930 2.71 3.61
Nonowner 310 159,988 0.75
General practice Owner 79 82,868 2.65 3.00
Nonowner 2,040 1,728,324 0.89
General surgery Owner 57 18,859 8.32 9.26
Nonowner 983 322,698 0.90
Internal Owner 191 232,022 3.43 1.91
medicine
Nonowner 2,596 2,630,615 1.79
Maxillofacial Owner 40 48,087 7.17 1.61
surgery
Nonowner 239 263,152 4.45
Nephrology Owner 10 9,988 6.41 3.27
Nonowner 107 56,623 1.96
Neurological Owner 49 8,832 71.78 1.38
surgery
Nonowner 115 21,544 52.03
Neurology Owner 89 45,802 52.31 1.36
Nonowner 282 136,066 38.55
Neuropsychiatry Owner 16 33,486 5.70 1.16
Nonowner 110 178,605 4.91
Ophthalmology Owner 18 34,358 2.30 6.43
Nonowner 787 1,398,387 0.36
Orthopedic Owner 146 77,329 20.34 1.59
surgery
Nonowner 721 333,603 12.78
Otolaryngology Owner 25 21,513 9.30 2.22
Nonowner 329 258,038 4.19
Preventive Owner 10 16,331 4.10 2.04
medicine
Nonowner 112 107,171 2.02
Psychiatry Owner 12 4,194 8.11 13.31
Nonowner 551 287,307 0.61
Pulmonary Owner 29 29,148 3.05 2.60
disease
Nonowner 232 173,906 1.17
Urology Owner 35 32,568 4.97 5.60
Nonowner 474 378,486 0.89
All listed Owner 952 876,094 -- 2.02\a
specialties
Nonowner 12,596 10,851,302 --
-----------------------------------------------------------------------------------------
Notes: For some physicians with an investment interest in an imaging
center, we could not readily determine if the center offered MRI
services. Those physicians were excluded from this analysis.
This analysis excludes physician specialties where (1) either owners
or nonowners within the specialty made no MRI referrals or (2) the
MRI referrals by physicians in the specialty for owners and nonowners
combined accounted for less than 0.5 percent of all the MRI referrals
we matched to a referring physician. The MRI referrals included in
this analysis account for 93 percent of all the MRI referrals we
matched to a referring physician.
\a The ratio of MRI owner-to-nonowner referral rates for all
specialties combined is a weighted ratio based on the number of MRI
referrals by each specialty.
Table II.5
CT Referrals, by Referring Physician
Specialty and CT Ownership Status
Number CT referrals Ratio of CT
Referring of Number of per 1,000 owner-to-
physician CT ownership physicia office office nonowner referral
specialty status ns visits visits rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular Owner 83 105,403 9.93 1.70
disease
Nonowner 755 614,851 5.83
Endocrinology Owner 17 13,125 9.37 0.79
Nonowner 327 185,057 11.81
Family practice Owner 122 176,933 9.17 1.36
Nonowner 1,765 1,670,381 6.75
Gastroenterology Owner 43 34,882 24.28 0.84
Nonowner 296 155,036 28.77
General practice Owner 107 114,686 7.40 1.27
Nonowner 2,012 1,696,506 5.85
General surgery Owner 84 24,352 19.51 1.41
Nonowner 956 317,205 13.82
Internal Owner 295 404,157 12.63 1.32
medicine
Nonowner 2,492 2,458,480 9.57
Maxillofacial Owner 58 76,641 50.21 1.31
surgery
Nonowner 221 234,598 38.21
Neurological Owner 41 9,489 57.22 1.36
surgery
Nonowner 123 20,887 42.23
Neurology Owner 80 43,979 26.90 1.19
Nonowner 291 137,889 22.67
Neuropsychiatry Owner 14 29,782 5.24 1.04
Nonowner 112 182,309 5.04
Obstetrics/ Owner 114 18,402 6.63 1.04
gynecology
Nonowner 931 126,587 6.36
Ophthalmology Owner 23 32,019 0.62 0.84
Nonowner 782 1,400,726 0.74
Orthopedic Owner 139 73,961 12.36 1.67
surgery
Nonowner 728 336,971 7.42
Otolaryngology Owner 32 28,261 12.70 1.07
Nonowner 322 251,290 11.89
Preventive Owner 12 20,173 11.25 1.78
medicine
Nonowner 110 103,329 6.32
Pulmonary Owner 38 42,574 19.97 1.26
disease
Nonowner 223 160,480 15.80
Urology Owner 67 66,667 18.37 1.32
Nonowner 442 344,387 13.93
All listed Owner 1,369 1,315,486 -- 1.29\a
specialties
Nonowner 12,888 10,396,969 --
-----------------------------------------------------------------------------------------
Notes: For some physicians with an investment interest in an imaging
center, we could not readily determine if the center offered CT
services. Those physicians were excluded from this analysis.
This analysis excludes physician specialties where (1) either owners
or nonowners within the specialty made no CT referrals, (2) the CT
referrals by physicians in the specialty for owners and nonowners
combined accounted for less than 0.5 percent of all the CT referrals
we matched to a referring physician, or (3) there were fewer than 10
physicians in either category. The CT referrals included in this
analysis account for 92 percent of all the CT referrals we matched to
a referring physician.
\a The ratio of CT owner-to-nonowner referral rates for all
specialties combined is a weighted ratio based on the number of CT
referrals by each specialty.
IN-PRACTICE AND REFERRAL IMAGING
RATES
========================================================= Appendix III
The tables in this appendix provide detailed comparisons between
in-practice and referral imaging rates for Florida physicians. As
described in appendix I, we classified each physician's predominant
imaging pattern as either in-practice or referral for each of seven
types of imaging services.
Table III.1 provides a summary of the physician, imaging service, and
office visit counts for in-practice and referring physicians by type
of imaging service. This table also provides summary ratios of the
in-practice and referral rates, weighted by the number of imaging
services ordered by each physician specialty to adjust for variations
in the use of imaging among physician specialties. The summary
ratios show that in-practice imaging rates exceeded referral imaging
rates for all types of imaging services. The in-practice rates were
about 3 times higher for MRI scans; about 2 times higher for CT
scans; 4.5 to 5 times higher for ultrasound, echocardiography, and
diagnostic nuclear medicine imaging; and about 2 times higher for
complex and simple X rays.
Tables III.2 through III.8 provide detailed information on imaging
rates by physician specialty for each of seven types of diagnostic
imaging services--MRI, CT, ultrasound, echocardiography, diagnostic
nuclear medicine, complex X rays, and simple X rays.
Table III.1
Summary of Physician, Imaging Service,
and Office Visit Counts, by Type of
Imaging Service for In-practice and
Referred Imaging Services
Ratio of in-
practice-to-
referral
In- In- In- imaging rates
Type of service practice Referral Total practice Referral Total practice Referral Total \a
------------------ -------- ------------- ------------- -------- ------------ ---------- ---------- ------------ ----------- --------------
MRI 169 13,650 13,819 2,622 33,939 36,561 142,985 11,885,366 12,028,351 3.06
CT 310 14,360 14,670 7,273 112,171 119,444 291,756 11,792,169 12,083,925 1.95
Ultrasound 1,646 10,899 12,545 112,030 94,169 206,199 2,254,372 8,695,337 10,949,709 5.13
Echocardiography 1,185 9,995 11,180 70,442 51,576 122,018 1,327,817 9,031,389 10,359,206 4.78
Nuclear medicine 418 13,677 14,095 15,193 67,406 82,599 390,600 12,321,120 12,711,720 4.52
Complex X ray 773 11,879 12,652 19,595 116,389 135,984 699,675 9,534,698 10,234,373 1.92
Simple X ray 4,897 10,222 15,119 971,140 646,856 1,617,996 4,824,447 8,079,180 12,903,627 2.10
-----------------------------------------------------------------------------------------------------------------------------------------------------
Note: For each type of imaging service (for example, MRI or CT),
this summary excludes physicians, imaging services, and office visits
for physician specialties where (1) the physicians in that specialty
accounted for less than 0.5 percent of the total imaging services
ordered for that type of imaging or (2) there were no physicians in
either the in-practice or referral categories. After applying these
cutoff criteria, this summary includes about 2,321,000 imaging
services, or about 95 percent of the 2,441,000 imaging services in
our database.
\a The ratios of in-practice-to-referral imaging rates are weighted
by physician specialty. For each type of imaging service (for
example, MRI or CT), the weighting factor for each specialty is the
number of the total imaging services of that type that were ordered
by the physicians in that specialty. We computed a weighted ratio to
adjust for differences in the use of imaging among physician
specialties.
Table III.2
MRI In-practice and Referral Rates
Number MRI scans
of Number of per 1,000 Ratio of in-
Physician Imaging physicia office office practice-
specialty\a pattern ns visits visits to-referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 9 3,729 9.65 10.20
disease
Referral 856 757,541 0.95
Family practice In-practice 4 2,987 2.68 1.77
Referral 1,906 1,886,696 1.51
Gastroenterology In-practice 7 4,779 5.65 5.30
Referral 342 193,272 1.07
General practice In-practice 5 4,112 4.38 4.50
Referral 2,140 1,844,837 0.97
General surgery In-practice 6 9,353 12.40 9.00
Referral 1,053 337,372 1.38
Internal In-practice 50 47,989 7.73 3.96
medicine
Referral 2,790 2,882,292 1.95
Maxillofacial In-practice 7 5,969 14.91 3.02
surgery
Referral 283 323,736 4.93
Nephrology In-practice 2 1,715 25.66 9.75
Referral 123 73,364 2.63
Neurological In-practice 7 1,771 90.91 1.44
surgery
Referral 165 30,662 63.24
Neurology In-practice 25 15,558 81.31 1.77
Referral 368 179,441 45.84
Neuropsychiatry In-practice 3 4,212 6.89 1.33
Referral 123 207,879 5.17
Ophthalmology In-practice 6 9,844 3.05 7.49
Referral 807 1,435,430 0.41
Orthopedic In-practice 13 7,391 31.25 2.15
surgery
Referral 881 415,975 14.51
Otolaryngology In-practice 7 6,065 12.04 2.58
Referral 350 278,397 4.66
Preventive In-practice 6 7,720 8.42 3.56
medicine
Referral 118 119,211 2.37
Psychiatry In-practice 2 484 8.26 11.50
Referral 563 292,159 0.72
Pulmonary In-practice 2 1,064 21.62 14.68
disease
Referral 265 211,195 1.47
Urology In-practice 8 8,243 3.88 3.02
Referral 517 415,907 1.29
All listed In-practice 169 142,985 -- 3.06\b
specialties
Referral 13,650 11,885,366 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
MRI scans, (2) the number of MRI scans ordered by the physicians in
the specialty accounted for less than 0.5 percent of the total MRI
scans used in our analysis, or (3) fewer than 10 physicians in that
specialty ordered MRI scans. The specialties included in this table
accounted for over 95 percent of the MRI scans used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of MRI scans ordered by physicians in each specialty.
Table III.3
CT In-practice and Referral Rates
Number
of Number of CT scans per Ratio of in-
Physician Imaging physicia office 1,000 office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 16 9,064 15.56 2.26
disease
Referral 849 752,206 6.89
Endocrinology In-practice 5 7,016 8.41 0.70
Referral 340 191,940 12.02
Family practice In-practice 20 27,808 11.94 1.69
Referral 1,890 1,861,875 7.05
Gastroenterology In-practice 12 7,509 40.48 1.39
Referral 337 190,542 29.12
General practice In-practice 7 8,992 11.12 1.84
Referral 2,138 1,839,957 6.06
General surgery In-practice 16 8,715 30.06 2.07
Referral 1,043 338,010 14.51
Internal In-practice 87 100,953 20.32 1.96
medicine
Referral 2,753 2,829,328 10.36
Maxillofacial In-practice 11 11,997 80.77 1.94
surgery
Referral 279 317,708 41.58
Nephrology In-practice 4 3,194 28.18 2.97
Referral 121 71,885 9.50
Neurological In-practice 9 2,345 90.41 1.75
surgery
Referral 163 30,088 51.75
Neurology In-practice 43 24,604 59.22 2.22
Referral 350 170,395 26.71
Neuropsychiatry In-practice 5 9,801 12.75 2.39
Referral 121 202,290 5.33
Obstetrics/ In-practice 13 3,125 17.28 2.68
gynecology
Referral 1,058 146,136 6.45
Ophthalmology In-practice 12 19,755 4.96 6.63
Referral 801 1,425,519 0.75
Orthopedic In-practice 16 10,676 13.68 1.61
surgery
Referral 878 412,690 8.50
Otolaryngology In-practice 6 4,990 28.86 2.34
Referral 351 279,472 12.34
Preventive In-practice 9 12,919 14.71 1.87
medicine
Referral 115 114,012 7.85
Pulmonary In-practice 6 6,398 23.91 1.43
disease
Referral 261 205,861 16.78
Urology In-practice 13 11,895 32.45 2.14
Referral 512 412,255 15.18
All listed In-practice 310 291,756 -- 1.95\b
specialties
Referral 14,360 11,792,169 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
CT scans, (2) the number of CT scans ordered by the physicians in the
specialty accounted for less than 0.5 percent of the total CT scans
used in our analyses, or (3) fewer than 10 physicians in that
specialty ordered CT scans. The specialties included in this table
accounted for over 95 percent of the CT scans used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of CT scans ordered by physicians in each specialty.
Table III.4
Ultrasound In-practice and Referral
Rates
Ultrasound
Number services
of Number of per Ratio of in-
Physician Imaging physicia office 1,000 office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 87 101,515 36.55 4.02
disease
Referral 778 659,755 9.10
Family practice In-practice 67 97,290 15.82 1.74
Referral 1,843 1,792,393 9.07
Gastroenterology In-practice 20 15,222 77.72 3.13
Referral 329 182,829 24.82
General practice In-practice 78 96,784 29.01 3.55
Referral 2,067 1,752,165 8.18
General surgery In-practice 55 22,614 41.26 2.98
Referral 1,004 324,111 13.84
Internal In-practice 189 243,400 27.30 2.59
medicine
Referral 2,651 2,686,881 10.56
Maxillofacial In-practice 11 14,669 13.98 2.64
surgery
Referral 279 315,036 5.30
Nephrology In-practice 3 2,453 40.77 2.14
Referral 122 72,626 19.03
Neuropsychiatry In-practice 9 16,245 7.94 1.90
Referral 117 195,846 4.18
Obstetrics/ In-practice 111 17,168 34.42 1.31
gynecology
Referral 960 132,093 26.28
Ophthalmology In-practice 698 1,347,767 49.33 10.59
Referral 115 97,507 4.66
Preventive In-practice 13 18,390 23.16 2.29
medicine
Referral 111 108,541 10.12
Pulmonary In-practice 10 13,197 22.20 4.17
disease
Referral 257 199,062 5.32
Urology In-practice 263 247,658 108.98 1.88
Referral 262 176,492 58.04
All listed In-practice 1,646 2,254,372 -- 5.13\b
specialties
Referral 10,899 8,695,337 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
ultrasound services, (2) the number of ultrasound services ordered by
the physicians in the specialty accounted for less than 0.5 percent
of the total ultrasound services used in our analyses, or (3) fewer
than 10 physicians in that specialty ordered ultrasound services.
The specialties included in this table accounted for over 95 percent
of the ultrasound services used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of ultrasound services ordered by physicians in each specialty.
Table III.5
Echocardiography In-practice and
Referral Rates
Echocardiogr
Number ams per
of Number of 1,000 Ratio of in-
Physician Imaging physicia office office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 464 460,045 80.80 2.63
disease
Referral 401 301,225 30.76
Family practice In-practice 78 93,240 26.36 5.63
Referral 1,832 1,796,443 4.68
Gastroenterology In-practice 12 7,211 14.15 4.53
Referral 337 190,840 3.12
General practice In-practice 84 106,783 40.77 7.90
Referral 2,061 1,742,166 5.16
General surgery In-practice 31 15,744 15.43 4.61
Referral 1,028 330,981 3.35
Internal In-practice 422 523,060 46.29 5.68
medicine
Referral 2,418 2,407,221 8.14
Maxillofacial In-practice 20 27,258 6.93 3.51
surgery
Referral 270 302,447 1.98
Nephrology In-practice 10 13,886 19.37 2.75
Referral 115 61,193 7.04
Neurology In-practice 21 14,810 15.80 6.59
Referral 372 180,189 2.40
Ophthalmology In-practice 15 27,314 4.58 9.08
Referral 798 1,417,960 0.50
Preventive In-practice 13 22,133 14.32 3.28
medicine
Referral 111 104,798 4.37
Pulmonary In-practice 15 16,333 47.02 9.63
disease
Referral 252 195,926 4.88
All listed In-practice 1,185 1,327,817 -- 4.78\b
specialties
Referral 9,995 9,031,389 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
echocardiograms, (2) the number of echocardiograms ordered by the
physicians in the specialty accounted for less than 0.5 percent of
the total echocardiograms used in our analyses, or (3) fewer than 10
physicians in that specialty ordered echocardiograms. The
specialties included in this table accounted for over 96 percent of
the echocardiograms used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of echocardiograms ordered by physicians in each specialty.
Table III.6
Nuclear Medicine In-practice and
Referral Rates
Number Nuclear
of Number of scans per Ratio of in-
Physician Imaging physicia office 1,000 office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 141 113,597 77.04 5.21
disease
Referral 724 647,673 14.79
Endocrinology In-practice 4 6,479 2.93 0.94
Referral 341 192,477 3.12
Family practice In-practice 12 17,480 13.79 4.07
Referral 1,898 1,872,203 3.38
Gastroenterology In-practice 11 6,575 11.41 1.55
Referral 338 191,476 7.36
General practice In-practice 16 19,969 45.32 16.50
Referral 2,129 1,828,980 2.75
General surgery In-practice 17 10,908 6.97 1.08
Referral 1,042 335,817 6.42
Internal In-practice 116 112,392 25.98 4.02
medicine
Referral 2,724 2,817,889 6.46
Maxillofacial In-practice 9 10,327 26.24 1.40
surgery
Referral 281 319,378 18.73
Neurological In-practice 6 1,681 16.06 1.08
surgery
Referral 166 30,752 14.86
Neurology In-practice 12 6,799 7.65 1.80
Referral 381 188,200 4.25
Neuropsychiatry In-practice 10 22,541 26.75 4.18
Referral 116 189,550 6.40
Ophthalmology In-practice 12 17,368 2.59 6.67
Referral 801 1,427,906 0.39
Orthopedic In-practice 16 9,580 15.34 1.35
surgery
Referral 878 413,786 11.39
Otolaryngology In-practice 5 3,471 6.63 4.89
Referral 352 280,991 1.36
Podiatry In-practice 1 2,064 0.48 0.98
Referral 620 850,071 0.49
Preventive In-practice 11 12,022 30.94 4.46
medicine
Referral 113 114,909 6.94
Pulmonary In-practice 6 6,731 25.85 3.27
disease
Referral 261 205,528 7.90
Urology In-practice 13 10,616 46.25 2.68
Referral 512 413,534 17.29
All listed In-practice 418 390,600 -- 4.52\b
specialties
Referral 13,677 12,321,120 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
nuclear medicine scans, (2) the number of nuclear medicine scans
ordered by the physicians in the specialty accounted for less than
0.5 percent of the total nuclear medicine scans used in our analyses,
or (3) fewer than 10 physicians in that specialty ordered nuclear
medicine scans. The specialties included in this table accounted for
96 percent of the nuclear medicine scans used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of nuclear medicine scans ordered by physicians in each specialty.
Table III.7
Complex X ray In-practice and Referral
Rates
Complex X
Number rays
of Number of per 1,000 Ratio of in-
Physician Imaging physicia office office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 57 41,585 16.91 1.90
disease
Referral 808 719,685 8.91
Endocrinology In-practice 6 7,939 10.20 1.85
Referral 339 191,017 5.51
Family practice In-practice 73 96,069 15.89 1.47
Referral 1,837 1,793,614 10.79
Gastroenterology In-practice 34 21,337 68.89 1.81
Referral 315 176,714 38.16
General practice In-practice 108 111,972 16.59 1.96
Referral 2,037 1,736,977 8.48
General surgery In-practice 29 18,818 23.06 0.96
Referral 1,030 327,907 23.96
Internal In-practice 187 206,001 21.26 1.76
medicine
Referral 2,653 2,724,280 12.10
Maxillofacial In-practice 12 18,033 15.25 2.42
surgery
Referral 278 311,672 6.30
Nephrology In-practice 6 5,688 43.42 4.04
Referral 119 69,391 10.74
Neurological In-practice 6 1,335 40.45 1.91
surgery
Referral 166 31,098 21.19
Neurology In-practice 15 7,969 17.82 5.33
Referral 378 187,030 3.34
Neuropsychiatry In-practice 8 14,379 19.33 5.45
Referral 118 197,712 3.55
Oral surgery In-practice 57 3,423 255.92 20.06
Referral 26 392 12.76
Orthopedic In-practice 50 29,409 16.12 3.24
surgery
Referral 844 393,957 4.98
Preventive In-practice 9 14,291 18.82 2.29
medicine
Referral 115 112,640 8.23
Pulmonary In-practice 19 20,076 18.23 2.39
disease
Referral 248 192,183 7.63
Thoracic surgery In-practice 4 1,300 209.23 6.66
Referral 136 24,330 31.40
Urology In-practice 93 80,051 73.58 1.45
Referral 432 344,099 50.76
All listed In-practice 773 699,675 -- 1.92\b
specialties
Referral 11,879 9,534,698 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
complex X rays, (2) the number of complex X rays ordered by the
physicians in the specialty accounted for less than 0.5 percent of
the total complex X rays used in our analyses, or (3) fewer than 10
physicians in that specialty ordered complex X rays. The specialties
included in this table accounted for 97 percent of the complex X rays
used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of complex X rays ordered by physicians in each specialty.
Table III.8
Simple X ray In-practice and Referral
Rates
Number Simple X
of Number of rays per Ratio of in-
Physician Imaging physicia office 1,000 office practice-to-
specialty\a pattern ns visits visits referral rates
---------------- -------------- -------- ------------ ------------ -----------------
Cardiovascular In-practice 311 355,080 185.90 2.69
disease
Referral 554 406,190 69.19
Endocrinology In-practice 29 19,804 214.25 0.95
Referral 316 179,152 225.24
Family practice In-practice 740 749,314 158.10 1.59
Referral 1,170 1,140,369 99.34
Gastroenterology In-practice 72 52,332 206.36 3.31
Referral 277 145,719 62.31
General practice In-practice 643 588,605 187.69 1.82
Referral 1,502 1,260,344 102.93
General surgery In-practice 98 63,028 165.23 1.39
Referral 961 283,697 118.64
Internal In-practice 1,053 1,256,899 192.98 1.97
medicine
Referral 1,787 1,673,382 97.99
Maxillofacial In-practice 59 83,714 175.38 1.77
surgery
Referral 231 245,991 99.02
Nephrology In-practice 18 19,469 200.78 2.15
Referral 107 55,610 93.18
Neurology In-practice 32 18,192 79.27 2.06
Referral 361 176,807 38.44
Neuropsychiatry In-practice 74 139,340 255.59 2.23
Referral 52 72,751 114.75
Obstetrics/ In-practice 96 21,986 201.58 1.67
gynecology
Referral 975 127,275 120.46
Ophthalmology In-practice 19 30,507 27.93 2.81
Referral 794 1,414,767 9.92
Orthopedic In-practice 810 403,701 567.81 1.86
surgery
Referral 84 19,665 305.21
Otolaryngology In-practice 91 79,145 102.95 2.88
Referral 266 205,317 35.78
Podiatry In-practice 545 760,575 100.81 6.04
Referral 76 91,560 16.68
Preventive In-practice 28 39,881 187.36 3.08
medicine
Referral 96 87,050 60.92
Pulmonary In-practice 121 98,608 224.02 1.55
disease
Referral 146 113,651 144.64
Urology In-practice 58 44,267 82.27 1.74
Referral 467 379,883 47.39
All listed In-practice 4,897 4,824,447 -- 2.10\b
specialties
Referral 10,222 8,079,180 --
-----------------------------------------------------------------------------------------
\a This table excludes specialties where (1) physicians in one or
both of the comparison groups within the specialty did not order any
simple X rays, (2) the number of simple X rays ordered by the
physicians in the specialty accounted for less than 0.5 percent of
the total simple X rays used in our analyses, or (3) fewer than 10
physicians in that specialty ordered simple X rays. The specialties
included in this table accounted for 96 percent of the simple X rays
used in our analyses.
\b The ratio for all specialties combined is weighted by the number
of simple X rays ordered by physicians in each specialty.
(See figure in printed edition.)APPENDIX IV
COMMENTS FROM THE DEPARTMENT OF
HEALTH AND HUMAN SERVICES
========================================================= Appendix III
(See figure in printed edition.)
(See figure in printed edition.)
MAJOR CONTRIBUTORS TO THIS REPORT
=========================================================== Appendix V
Edwin P. Stropko, Assistant Director, (202) 512-7108
William M. Reis, Evaluator-in-Charge
Mary E. Fleischman
Herman A.T. Jenich
Lyle H. Lanier, Jr.
Suzanne C. Rubins
Vanessa R. Taylor
Sibyl L. Tilson