MEDICARE

Higher Use of Costly 

Prostate Cancer 

Treatment by 

Providers Who SelfRefer Warrants 

Scrutiny

Report to Congressional Requesters

July 2013

GAO-13-525

United States Government Accountability Office
United States Government Accountability Office

Highlights of GAO-13-525, a report to 

congressional requesters

July 2013

MEDICARE

Higher Use of Costly Prostate Cancer Treatment by 

Providers Who Self-Refer Warrants Scrutiny

Why GAO Did This Study

Questions have been raised about selfreferral’s role in Medicare Part B 

expenditures’ rapid growth. Selfreferral occurs when a provider refers 

patients to entities in which the 

provider or the provider’s family 

members have a financial interest. 

Services that can be self-referred 

under certain circumstances include 

IMRT, a common and costly treatment 

for prostate cancer. GAO was asked to 

examine Medicare self-referral trends 

among radiation oncology services. 

This report examines (1) trends in the 

number of and expenditures for 

prostate cancer-related IMRT services 

provided by self-referring and non-selfreferring provider groups from 2006 

through 2010 and (2) how the 

percentage of prostate cancer patients 

referred for IMRT may differ on the 

basis of whether providers self-refer. 

GAO analyzed Medicare Part B claims 

and developed a claims-based 

methodology to identify self-referring 

groups and providers. GAO also 

interviewed officials from the Centers 

for Medicare & Medicaid Services 

(CMS), which administers Medicare, 

and other stakeholders.

What GAO Recommends

Congress should consider directing the 

Secretary of Health and Human 

Services, whose agency oversees 

CMS, to require providers to disclose 

their financial interests in IMRT to their 

patients. GAO also recommends that 

CMS identify and monitor self-referral 

of IMRT services. HHS disagreed with 

GAO's recommendation. Given the 

magnitude of GAO’s findings, GAO 

maintains CMS should identify and 

monitor self-referral of IMRT services. 

What GAO Found

The number of Medicare prostate cancer–related intensity-modulated radiation 

therapy (IMRT) services performed by self-referring groups increased rapidly, 

while declining for non-self-referring groups from 2006 to 2010. Over this period, 

the number of prostate cancer–related IMRT services performed by self-referring 

groups increased from about 80,000 to 366,000. Consistent with that growth, 

expenditures associated with these services and the number of self-referring 

groups also increased. The growth in services performed by self-referring groups 

was due entirely to limited-specialty groups—groups comprised of urologists and 

a small number of other specialties—rather than multispecialty groups. 

Providers substantially increased the percentage of their prostate cancer patients 

they referred for IMRT after they began to self-refer. Providers that began selfreferring in 2008 or 2009—referred to as switchers—referred 54 percent of their 

patients who were diagnosed with prostate cancer in 2009 for IMRT, compared 

to 37 percent of their patients diagnosed in 2007. In contrast, providers who did 

not begin to self-refer—that is, non-self-referrers and providers who self-referred 

the entire period—experienced much smaller changes over the same period. 

Among all providers who referred a Medicare beneficiary diagnosed with prostate 

cancer in 2009, those that self-referred were 53 percent more likely to refer their 

patients for IMRT and less likely to refer them for other treatments, especially a 

radical prostatectomy or brachytherapy. Compared to IMRT, those treatments 

are less costly and often considered equally appropriate but have different risks 

and side effects. Factors such as age, geographic location, and patient health did 

not explain the large differences between self-referring and non-self-referring 

providers. These analyses suggest that financial incentives for self-referring 

providers—specifically those in limited specialty groups—were likely a major 

factor driving the increase in the percentage of prostate cancer patients referred 

for IMRT. Medicare providers are generally not required to disclose that they selfrefer IMRT services, and the Department of Health and Human Services (HHS)

lacks the authority to establish such a requirement. Thus, beneficiaries may not 

be aware that their provider has a financial interest in recommending IMRT over 

alternative treatments that may be equally effective, have different risks and side 

effects, and are less expensive for Medicare and beneficiaries.

Change in the Percentage of Medicare Prostate Cancer Patients Providers Referred for IMRT 

after a Diagnosis of Prostate Cancer in 2007 or 2009

Type of 

provider

Percentage of 

providers’ patients 

referred for IMRT 

among beneficiaries 

diagnosed in 2007

Percentage of 

providers’ patients 

referred for IMRT 

among beneficiaries 

diagnosed in 2009

Percentage 

point change 

from

2007 to 2009

Percentage more 

or less likely 

providers were to 

refer patients for 

IMRT in 2009 

compared to 2007

Switchers 37.0% 54.2% 17.2 46.6%

Non-self-referrers 31.4 33.1 1.7 5.5

Self-referrers 55.7 52.9 -2.8 -5.1

Source: GAO analysis of CMS data.

Note: Switchers did not self-refer in 2006 or 2007 but began to self-refer in either 2008 or 2009. The 

percentage by which providers were more or less likely to refer patients for IMRT in 2009 compared 

to 2007 is equivalent to the percentage point change from 2007 to 2009 divided by the percentage of 

providers’ patients referred for IMRT among beneficiaries diagnosed in 2007.

View GAO-13-525. For more information, 

contact James C. Cosgrove at (202) 512-7114 

or cosgrovej@gao.gov.
Page i GAO-13-525 Medicare Self-Referral of IMRT Services

Letter 1 

Background 5

Number of and Expenditures for Prostate Cancer–Related IMRT 

Services Provided by Self-Referring Groups Grew Rapidly, while 

Declining for Non-Self-Referring Groups 10

Self-Referring Providers Referred Their Prostate Cancer Patients 

for IMRT More Frequently than Non-Self-Referring Providers 15

Conclusions 20

Matter for Congressional Consideration 21

Recommendation for Executive Action 21

Agency and Third-Party Comments and Our Evaluation 22

Appendix I Scope and Methods 30

Appendix II Change in Prostate Cancer–Related IMRT Services and 

Expenditures by Setting 36

Appendix III Discrete Prostate Cancer Treatment Categories 38

Appendix IV Distribution of Prostate Cancer Treatments by Age 39

Appendix V Change in Prostate Cancer Treatment Patterns over Time 

for Different Types of Providers 40

Appendix VI Comments from the Department of Health and Human 

Services 42

Appendix VII GAO Contact and Staff Acknowledgments 44

Contents 
Page ii GAO-13-525 Medicare Self-Referral of IMRT Services

Tables

Table 1: Prostate Cancer Treatments 7

Table 2: Percentage of Self-Referring and Non-Self-Referring 

Providers’ Medicare Patients Referred for a Given 

Treatment after a Diagnosis of Prostate Cancer in 2009 16

Table 3: Change in the Percentage of Medicare Prostate Cancer 

Patients Providers Referred for IMRT after a Diagnosis of 

Prostate Cancer in 2007 or 2009 19

Table 4: Percentage of Self-Referring and Non-Self-Referring

Providers’ Medicare Patients Referred for a Given 

Treatment or Combination of Treatments after Diagnosis 

of Prostate Cancer in 2009 38

Table 5: Percentage of Self-Referring and Non-Self-Referring 

Providers’ Medicare Patients Referred for a Given 

Treatment after a Diagnosis of Prostate Cancer in 2009 by 

Age of Beneficiary 39

Table 6: Change in the Percentage of Medicare Prostate Cancer 

Patients Providers Referred for a Given Treatment after a 

Diagnosis of Prostate Cancer in 2007 or 2009 40

Figures

Figure 1: Number of Medicare Prostate Cancer–Related IMRT 

Services Performed by Self-Referring and Non-SelfReferring Groups in Physician Offices, 2006-2010 11

Figure 2: Number of Medicare Prostate Cancer–Related IMRT 

Services Performed by Limited-Specialty and 

Multispecialty Self-Referring Groups, 2006-2010 13

Figure 3: Changes in Medicare Prostate Cancer–Related IMRT 

Expenditures for Services Performed by Self-Referring 

and Non-Self-Referring Provider Groups in Physician 

Offices, 2006-2010 14

Figure 4: Number of Medicare Prostate Cancer–Related IMRT 

Services by Setting, 2006-2010 36

Figure 5: Expenditures for Medicare Prostate Cancer–Related 

IMRT Services by Setting, 2006-2010 37
Page iii GAO-13-525 Medicare Self-Referral of IMRT Services

Abbreviations

3D-CRT three-dimensional conformal radiation therapy

ASTRO American Society for Radiation Oncology

AUA American Urological Association

CMS Centers for Medicare & Medicaid Services

EBRT external beam radiation therapy

FFS fee-for-service 

HCPCS Healthcare Common Procedure Coding System

HHS Department of Health and Human Services

IMRT intensity-modulated radiation therapy

IOAS in-office ancillary services

LUGPA Large Urology Group Practice Association

NPI national provider identifier

PPACA Patient Protection and Affordable Care Act

PSA prostate-specific antigen

SEER Surveillance Epidemiology and End Results

TIN taxpayer identification number

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Page 1 GAO-13-525 Medicare Self-Referral of IMRT Services

441 G St. N.W.

Washington, DC 20548

July 19, 2013

Congressional Requesters

Expenditures for Medicare Part B services—which include physician and 

other outpatient services—have grown rapidly, increasing annually at 

5.9 percent, on average, from 2007 through 2011. In comparison, the 

national economy grew by less than half that rate during the same period.

Policymakers have questioned whether some of the growth in spending 

for Part B services may be attributed to self-referral, which occurs when 

providers refer their patients to entities—such as themselves or a group 

practice—in which they or a member of their families have a financial 

relationship.1 While federal law generally prohibits self-referral under 

Medicare, there are exceptions for certain services and arrangements.2

Questions have been raised about the effect of self-referral arrangements 

on the utilization of IMRT services reimbursed under Medicare Part B.

Critics of such self-referral arrangements suggest that there may be a 

financial incentive to overutilize IMRT because diagnosing providers can 

earn more by self-referring IMRT services than if patients were referred 

Among the Medicare diagnostic and therapeutic services that may be 

self-referred under one of these exceptions is intensity-modulated 

radiation therapy (IMRT), a form of external beam radiation therapy 

(EBRT) commonly used to treat prostate cancer. While there are multiple 

effective treatments for prostate cancer, IMRT is one of the most costly 

options. In 2010, expenditures for prostate cancer–related IMRT services 

accounted for about 55 percent of the $1.27 billion that Medicare paid for 

all IMRT services under Medicare Part B.

 

1

Providers in our analysis that could self-refer could include physicians and other 

providers, such as nurse practitioners and physician assistants.

2

Compliance with the physician self-referral law, commonly known as the Stark law, is 

outside the scope of this report. The Stark law prohibits physicians from making referrals 

for certain designated health services paid for by Medicare, to entities with which the 

physicians or immediate family members have a financial relationship, unless the 

arrangement complies with a specified exception, such as in-office ancillary services. 

42 U.S.C. § 1395nn(b)(2). The requirements of the in-office ancillary services exception 

are found at 42 C.F.R. § 411.355(b) (2012).

 
 

Page 2 GAO-13-525 Medicare Self-Referral of IMRT Services

for other treatments.3 Other treatments for prostate cancer are often 

considered equally appropriate, as experts have not established a “gold 

standard” for the treatment of cancer that has not spread beyond the 

prostate (i.e., localized prostate cancer), which represents a large 

majority of newly diagnosed prostate cancers.4

You asked us to examine Medicare self-referral trends among radiation 

oncology services. In this report, we (1) compare trends in the number of 

and expenditures for prostate cancer–related IMRT services provided by 

self-referring and non-self-referring provider groups from 2006 through 

2010 and (2) examine how the percentage of prostate cancer patients 

referred for IMRT may differ on the basis of whether providers self-refer.

Proponents of self-referral 

arrangements contend that the self-referral of IMRT services does not 

affect clinical decision making and that patients benefit from self-referral 

through, for example, improved coordination among the providers who 

diagnose and treat patients.

To compare trends in the number of and expenditures for prostate 

cancer–related IMRT services provided by self-referring and non-selfreferring groups in provider offices from 2006 through 2010, we analyzed 

IMRT delivery claims from the Medicare Part B Carrier file.5

 

3

For example, see Benjamin P. Falit, Cary P. Gross, and Kenneth B. Roberts, “Integrated 

Prostate Cancer Centers and Over-Utilization of IMRT: A Close Look at Fee-For-Service 

Medicine in Radiation Oncology,” International Journal of Radiation Oncology • Biology • 

Physics 76, no. 5 (April 2010): 1285-88.

We identified 

4

For instance, for a subset of localized prostate cancers that are low risk, IMRT, 

brachytherapy, and a radical prostatectomy are all among the treatments considered 

appropriate. According to the National Cancer Institute, 81 percent of men who were 

diagnosed with prostate cancer from 2002 through 2008 in 18 geographic areas that 

provided cancer data to the National Cancer Institute were diagnosed with localized 

prostate cancer, while the rest were diagnosed at an unknown stage (3 percent) or after 

the cancer had spread regionally (12 percent) or distantly (4 percent). See 

http://seer.cancer.gov/statfacts/html/prost.html, accessed December 18, 2012.

5

IMRT delivery codes represent individual treatment sessions during which patients 

receive radiation. In addition to receiving radiation, patients receive several different types 

of services during a course of IMRT. Our analysis of self-referred prostate cancer–related 

IMRT services is limited to those services performed in physician offices. We focused on 

this setting because our work showed rapid growth in this setting compared to hospital 

outpatient departments and because the financial incentive for providers to self-refer is 

most direct when the service is performed in a physician office. Services performed by 

non-self-referring groups in the physician office setting could include services provided in 

places such as freestanding cancer centers. Throughout this report, we refer to services 

billed through the Carrier file as services performed in physician offices.
 

Page 3 GAO-13-525 Medicare Self-Referral of IMRT Services

prostate cancer–related IMRT services using diagnosis codes on the 

claims. Because there is no indicator or “flag” on the claim that identifies 

whether services are self-referred or non-self-referred and the Centers for 

Medicare & Medicaid Services (CMS), the agency that administers 

Medicare, has no other method for identifying whether a service was selfreferred, we developed a claims-based methodology for identifying 

provider group practices as self-referring or non-self-referring.6

Specifically, we classified groups as self-referring if the providers who 

administered IMRT for the group had a financial relationship with the 

same entity as the provider who referred the IMRT service.7

To examine how the percentage of prostate cancer patients referred for 

IMRT may differ on the basis of whether providers self-refer, we 

performed two separate analyses using the Medicare Part B Carrier and 

hospital outpatient files. First, we compared the percentage of prostate 

cancer patients that self-referring and non-self-referring providers referred 

for IMRT and other treatments within a year of being diagnosed in 2007 

or 2009. We classified referring providers as self-referring if they were the 

Additionally, 

in order to be considered self-referring, groups had to meet other volumerelated criteria, such as self-referring at least half of the courses of IMRT 

therapy the group provided. To ensure that how we defined our criteria 

were reliable, we tested alternative thresholds for defining self-referring 

groups and found that the observed patterns were similar regardless of 

the threshold used. We also analyzed trends in the utilization of prostate 

cancer–related IMRT services by whether the service was performed by a 

limited-specialty or multispecialty group. We defined groups as limited 

specialty in a given year if more than 75 percent of its office visits were 

performed by urologists, nonphysician practitioners (e.g., physician 

assistants), or providers whose specialty was related to the diagnosis or 

treatment of cancer, such as radiation oncologists. The remaining groups 

were comprised of providers from a large number of different specialties 

and were considered multispecialty groups. We examined the trends in 

prostate–cancer related IMRT services performed in hospital outpatient 

departments for context.

 

6

An indicator or “flag” could be, for example, a modifier that a provider lists on a claim to 

indicate that a service is self-referred. Providers currently use modifiers to provide 

additional information about a service to CMS. 

7

Providers could have a financial relationship with the same entity if, for example, they are 

part of the same group practice.
 

Page 4 GAO-13-525 Medicare Self-Referral of IMRT Services

performing provider on a claim that was paid to a self-referring provider 

group in the year of, before, or after a beneficiary’s prostate cancer 

diagnosis. All other providers were considered non-self-referring. In 

addition, we examined how, if at all, the referral patterns for non-selfreferring and self-referring providers were affected by beneficiary

characteristics such as age, geographic location (i.e., urban or rural), and 

beneficiary health.8

We took several steps to ensure that the data used to produce this report 

were sufficiently reliable. Specifically, we assessed the reliability of the 

CMS data we used by interviewing officials responsible for overseeing 

these data sources, reviewing relevant documentation, and examining the 

data for obvious errors. We determined that the data were sufficiently 

As part of our examination of beneficiary health, we 

examined how, if at all, provider referral patterns were affected by clinical 

characteristics of patients’ prostate cancers, which were obtained from 

the New York State Cancer Registry, for beneficiaries who lived in New 

York and were diagnosed with prostate cancer in either 2007 or 2009.

The results of the New York analysis are not generalizable to the entire 

Medicare population. We used clinical information from the New York 

State Cancer Registry because such information is not available on 

Medicare claims, and we determined that the geographic areas included 

in another common source of such information—Surveillance 

Epidemiology and End Results (SEER) data—did not sufficiently overlap 

with areas in which IMRT self-referral was prevalent during our study 

period. Second, we determined whether the percentage of providers’ 

prostate cancer patients referred for IMRT and other treatments changed 

after they began to self-refer. Specifically, we identified a group of 

providers, which we called “switchers,” that did not self-refer in 2006 or 

2007 but began to self-refer in either 2008 or 2009. We then analyzed the 

change in the percentage of switchers’ newly diagnosed prostate cancer 

patients referred for IMRT and other treatments before and after 

switchers began to self-refer. We compared the change for this group of 

providers to the change among providers who did not begin to self-refer 

IMRT services during this period. For both analyses, we counted IMRT 

and other treatments regardless of the setting in which they were 

performed.

 

8

We defined urban areas as metropolitan statistical areas, a geographic entity defined by 

the Office of Management and Budget as a core urban area of 50,000 or more population; 

all other settings were considered rural.
 

Page 5 GAO-13-525 Medicare Self-Referral of IMRT Services

reliable for the purposes of our study. (See app. I for more details on our 

scope and methodology.)

We conducted this performance audit from May 2010 through July 2013 

in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our 

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

Prostate cancer patients choose among multiple treatments that are often 

considered equally appropriate but can have different risks and side 

effects. The treatments can also vary in cost, with IMRT being one of the 

most costly options.

Cancer of the prostate—a gland located at the base of the urinary 

bladder—is the second most common cancer among men in the United 

States, with approximately 1 in 6 men receiving a diagnosis of prostate 

cancer in his lifetime.9

IMRT is one of multiple treatment options available to patients with 

prostate cancer. The type of treatment a prostate cancer patient chooses 

depends on a number of different factors such as life expectancy, overall 

health, personal preferences, provider recommendations, and the clinical 

characteristics of a patient’s prostate cancer. For many men, multiple 

In 2010, there were an estimated 218,000 new 

cases of prostate cancer and approximately 32,000 deaths due to 

prostate cancer. Most men in the United States are diagnosed with 

prostate cancer as a result of an abnormal digital rectal exam or prostatespecific antigen test. After an abnormal test result, beneficiaries often 

undergo a prostate biopsy, during which a provider—typically a 

urologist—removes small amounts of prostate tissue. Another provider 

then examines the tissue to determine whether a beneficiary has prostate 

cancer.

 

9

National Cancer Institute. See http://seer.cancer.gov/statfacts/html/prost.html, accessed 

December 18, 2012. Skin cancer is the most common form of cancer.

Background 

Diagnosis and Treatment 

of Prostate Cancer
 

Page 6 GAO-13-525 Medicare Self-Referral of IMRT Services

treatment options are considered equally appropriate.10 For instance, 

IMRT, brachytherapy, and a radical prostatectomy are all among the 

treatments considered appropriate for men with low-risk prostate 

cancer.11 Even though such treatments are often considered equally 

appropriate, the risks and side effects for each treatment are different.

Compared to IMRT, prostate cancer patients undergoing a radical 

prostatectomy have a higher rate of short term urinary problems and 

erectile dysfunction but do not face bowel-related side effects, which are 

experienced by some men undergoing IMRT.12 Compared to IMRT, 

prostate cancer patients undergoing brachytherapy have lower rates of 

bowel-related side effects but about 1 in 10 patients undergoing 

brachytherapy experience acute urinary retention. Also, several studies 

have reported that physician recommendations play a large role in 

influencing a patient’s decision,13 and another study found that the use of 

a particular prostate cancer treatment decreased after its payment was 

reduced, suggesting that financial incentives may have influenced 

treatment decisions.14

 

10Men can also receive a combination of therapies, such as brachytherapy combined with 

EBRT. 

Currently, providers who self-refer IMRT services 

are generally not required to disclose to their patients that they have a 

11National Comprehensive Cancer Network, NCCN Clinical Practice Guidelines in 

Oncology (NCCN GuidelinesTM): Prostate Cancer (June 2011).

12Institute for Clinical and Economic Review, “Management Options for Low-Risk Prostate 

Cancer: A Report on Comparative Effectiveness and Value” (Sept. 16, 2009).

13Steven B. Zelladt et al., “Why Do Men Choose One Treatment over Another? A Review 

of Patient Decision Making for Localized Prostate Cancer,” Cancer 106, no. 9 (May 1, 

2006): 1865-74.

14Vahakn B. Shahinian, Yong-Fang Kuo, and Scott M. Gilbert, “Reimbursement Policy and 

Androgen-Deprivation Therapy for Prostate Cancer,” The New England Journal of 

Medicine 363, no. 19 (Nov. 4, 2010): 1822-32.
 

Page 7 GAO-13-525 Medicare Self-Referral of IMRT Services

financial interest in the service.15

Table 1: Prostate Cancer Treatments

Some common prostate cancer 

treatments are summarized in table 1.

Treatment Description

Radical prostatectomy A radical prostatectomy is a surgical procedure in which the entire prostate gland is 

removed. A prostatectomy can be performed with or without robotic assistance.

Three-dimensional conformal radiation 

therapy (3D-CRT)

3D-CRT is a form of external beam radiation therapy (EBRT) during which multiple doses 

of radiation from an external source are administered over several weeks. In 3D-CRT, 

radiation beams are shaped in an attempt to maximize the amount of radiation the tumor 

receives and reduce the amount of radiation to which normal tissue is exposed.

Intensity-modulated radiation therapy 

(IMRT)

IMRT is a newer and an even more precise form of EBRT that allows even more radiation 

to be delivered to the tumor while sparing normal tissue.

Brachytherapy Brachytherapy is a treatment that involves the implantation of radioactive sources directly 

inside the prostate.

Active surveillance Active surveillance is a regimen of following a patient’s condition without giving any 

treatment, unless the patient’s condition changes. An exact regimen has not been 

established for active surveillance. However, typical protocols involve periodic physical 

examination, prostate-specific antigen testing, and repeat prostate biopsies. 

Hormone therapy Hormone therapy is a treatment that removes or blocks the actions of male sex hormones, 

which can cause prostate cancer to grow, in order to stop the growth of prostate cancer.

Drugs, surgery, or other hormones are used to reduce hormone production or block their 

effects.

 

15A physician with an ownership or investment interest in a hospital and who is a member 

of that hospital’s medical staff is required to disclose this financial interest when referring 

patients to that hospital under an exception to the general prohibition on Medicare selfreferral (Stark law). According to Physician Hospitals of America, an advocacy group for 

physician-owned hospitals, approximately 265 hospitals—or less than 5 percent of all 

hospitals—were physician-owned as of July 2012. See 42 C.F.R. § 411.362 (2012) for 

more information on additional requirements concerning physician ownership and 

investment in hospitals under the Stark law. The Patient Protection and Affordable Care 

Act (PPACA) created a new disclosure requirement for physicians who self-refer certain 

other in-office ancillary services under the Stark Law. Pub. L. No. 111-148, § 6003, 

124 Stat. 119, 697(2010). Specifically, referring physicians for certain advanced imaging 

services are required to inform their patients in writing at the time of the referral that the 

patient may obtain the service from another entity and provide the patients with a list of 

providers who furnish the service in the area in which the patient resides. 42 U.S.C. 

§ 13955nn(b)(2). No such requirement exists for physicians who self-refer IMRT services. 

CMS noted in the preamble to the final rule detailing this disclosure requirement that the 

agency does not have the authority to expand the disclosure requirements to services 

other than the radiology services referenced in PPACA. Medicare Program; Payment 

Policies Under the Physician Fee Schedule and Other Revisions to Part B for CY 2011, 

75 Fed. Reg. 73,170, 73,444 (Nov. 29, 2010).
 

Page 8 GAO-13-525 Medicare Self-Referral of IMRT Services

Treatment Description

Other treatments Other treatments for prostate cancer include stereotactic body radiotherapy / stereotactic 

radiosurgery (forms of EBRT during which beneficiaries receive larger daily doses of 

radiation over a shorter period of time), cryosurgery (freezing prostate cancer by injecting 

gases through thin needles inserted into the prostate), and proton beam therapy (a form of

EBRT that involves the use of particles—protons—rather than photons, which are used in 

the majority of EBRT treatments).

Source: GAO analysis of published literature.

Medicare reimbursement rates for IMRT delivery services varied over 

time, and rates are not directly comparable between settings.

Beneficiaries receive approximately 45 separate IMRT delivery services 

over several weeks during a course of IMRT to treat prostate cancer.

Medicare beneficiaries predominantly receive IMRT delivery services in 

two settings—physician offices or hospital outpatient departments. The 

Medicare reimbursement per IMRT delivery service increased from 

approximately $319 to $421 from 2006 to 2010 and then to $484 by 2013 

for services performed in hospital outpatient departments.16 For services 

performed in physician offices, the reimbursement rate decreased from 

approximately $690 to $511 from 2006 to 2010 and then to $406 by 

2013.17 The reimbursement rates for IMRT delivery services performed in 

physician offices and hospital outpatient departments are not directly 

comparable. For instance, if an IMRT delivery service was performed in a 

hospital outpatient department, payment includes the technical 

component for image guidance,18 which is almost always furnished with 

an IMRT service. In physician offices, image guidance is reimbursed 

separately.

 

16These payment rates are those hospitals receive under the Hospital Outpatient 

Prospective Payment System. Not all hospitals are paid under this system.

17These expenditures do not include the payment reductions that may result from 

implementation of the Budget Control Act of 2011. Pub. L. No. 112-25, 125 Stat. 240.

18The technical component is intended to cover the cost of performing a test, including the 

costs for equipment, supplies, and nonphysician staff.

Medicare Reimbursement 

for IMRT Services and 

Costs of Treatment 

Options for Prostate 

Cancer
 

Page 9 GAO-13-525 Medicare Self-Referral of IMRT Services

Researchers have consistently found that courses of IMRT, which include 

IMRT delivery and other services,19 are more costly than other treatments 

for prostate cancer, with the exception of proton therapy.20 Researchers 

have found IMRT to be more costly despite differences among studies in 

design and methodology, such as the services counted toward total 

treatment costs, the duration of time during which costs are studied 

(e.g., first year costs vs. lifetime costs), and the patient population 

studied. One recent study found that, among men diagnosed with 

prostate cancer in 2005, the cost to Medicare per course of treatment was 

approximately $14,000 to $15,000 higher for men receiving IMRT 

($31,574) than for men who received brachytherapy ($17,076) or a 

prostatectomy ($16,469 or $16,762, depending on the type of 

prostatectomy).21 Despite the 2013 reduction in the Medicare 

reimbursement rate for IMRT delivery services performed in physician 

offices, we found that IMRT remains substantially more expensive than 

other treatments for prostate cancer, with the exception of proton 

therapy.22

 

19Episodes of IMRT for prostate cancer include other services such as a radiotherapy 

dose plan, weekly management services, and weekly radiation physics consultations.

20For instance, see: Matthew R. Cooperberg et al., “Primary treatments for clinically 

localised prostate cancer: a comprehensive lifetime cost-utility analysis,” BJU International

111, no. 3 (March 2013): 437-50; or Chirag Shah et al., “Brachytherapy provides 

comparable outcomes and improved cost-effectiveness in the treatment of 

low/intermediate prostate cancer,” Brachytherapy 11 (2012): 441-45.

21P. L. Nguyen et al., “Cost implications of the rapid adoption of newer technologies for 

treating prostate cancer,” Journal of Clinical Oncology, 29, no. 12 (2011): 1517-24. 

Because Medicare beneficiaries often face cost-sharing requirements, more expensive 

treatments likely lead to higher beneficiary costs.

22To determine the effect of the payment reduction, we calculated the cost of a course of 

IMRT to treat prostate cancer using 2013 Medicare reimbursement rates and previously 

published methodologies. For an example of a methodology used, see Andre Konski et 

al., “Using Decision Analysis to Determine the Cost-Effectiveness of Intensity-Modulated 

Radiation Therapy in the Treatment of Intermediate Risk Prostate Cancer,” International 

Journal of Radiation Oncology • Biology • Physics 66, no. 2 (2006): 408-15.
 

Page 10 GAO-13-525 Medicare Self-Referral of IMRT Services

We found that the number of and expenditures for Medicare prostate 

cancer–related IMRT services performed by self-referring groups grew 

rapidly from 2006 through 2010. In contrast, the number of and Medicare 

expenditures for prostate cancer–related IMRT services performed by 

non-self-referring groups declined over the period.

From 2006 through 2010, the number of prostate cancer–related IMRT 

services performed by self-referring groups increased rapidly, while the 

number performed by non-self-referring groups decreased. The number 

of prostate cancer–related IMRT services performed by self-referring 

groups increased from approximately 80,000 to 366,000, an annual 

growth rate of 46 percent (see fig. 1). Consistent with that growth, the 

number of self-referring groups also increased rapidly over the period. In 

contrast, the number of prostate cancer–related IMRT services performed 

by non-self-referring groups in physician offices decreased from 

approximately 490,000 to 466,000, an annual decrease of 1 percent.

Number of and 

Expenditures for 

Prostate Cancer–

Related IMRT 

Services Provided by 

Self-Referring Groups 

Grew Rapidly, while 

Declining for NonSelf-Referring Groups

Number of Prostate 

Cancer–Related IMRT 

Services Performed 

Increased among SelfReferring Groups—

Specifically, LimitedSpecialty Groups—and 

Decreased among NonSelf-Referring Groups
 

Page 11 GAO-13-525 Medicare Self-Referral of IMRT Services

Figure 1: Number of Medicare Prostate Cancer–Related IMRT Services Performed 

by Self-Referring and Non-Self-Referring Groups in Physician Offices, 2006-2010

The rapid increase in prostate cancer–related IMRT services performed 

by self-referring groups coincided with several other trends from 2006 

through 2010. First, the number of prostate-cancer related IMRT services 

performed in hospital outpatient departments and by self-referring and 

non-self-referring groups all grew from 2006 to 2007. After 2007, the rapid 

increase in prostate cancer–related IMRT services performed by selfreferring groups coincided with declines in these services within hospital 

outpatient departments and among non-self-referring groups. Overall 

utilization of prostate cancer–related IMRT services therefore remained 

relatively flat across these settings after 2007, indicating a shift away from 

hospital outpatient departments and non-self-referring groups and toward 

self-referring groups. (See app. II for information on the trends in IMRT 

services performed in hospital outpatient departments.) Second, while the 

number of prostate cancer–related IMRT services provided to Medicare 

fee-for-service (FFS) beneficiaries has stabilized since 2007, the 
 

Page 12 GAO-13-525 Medicare Self-Referral of IMRT Services

percentage of newly diagnosed Medicare beneficiaries receiving IMRT 

has increased.23 While seemingly contradictory, these two trends 

occurring simultaneously can in part be explained by (1) a decrease in the 

total number of Medicare FFS beneficiaries from 2006 through 201024

and (2) a decrease in the number of men newly diagnosed with prostate 

cancer.25 Third, the increasing percentage of prostate cancer patients 

receiving IMRT may partially be explained by a shift from an older form of 

EBRT—3D-CRT—to a newer form—IMRT, though the largest effect of 

this substitution likely occurred earlier in our study period as IMRT largely 

replaced 3D-CRT by 2007.26

Our analysis showed that, from 2006 through 2010, the growth in prostate 

cancer–related IMRT services performed by self-referring groups was 

entirely due to an increase in the services performed by limited-specialty 

groups (see fig. 2). Limited-specialty groups were comprised of urologists 

and a small number of other specialties.27

 

23Specifically, our analysis of the distribution of treatments among men newly diagnosed 

with prostate cancer indicates that 33.7 percent and 36.8 percent of men diagnosed with 

prostate cancer in 2007 and 2009, respectively, were referred for IMRT.

Over our study period, the 

number of prostate cancer–related IMRT services performed by limitedspecialty self-referring groups increased over fivefold, from approximately 

24As a result of increased enrollment in Medicare Advantage, the number of Medicare 

FFS beneficiaries aged 65 and older decreased from 2006 to 2010, going from 

approximately 27.6 million to 26.4 million.

25In our analysis of the distribution of treatments among men newly diagnosed with 

prostate cancer, we found a 19 percent decrease in the number of Medicare FFS 

beneficiaries who were diagnosed with prostate cancer and met our other inclusion criteria 

in 2009 compared to 2007—58,289 and 71,834, respectively. In accordance with that, the 

number of prostate biopsies provided to Medicare FFS beneficiaries, which some 

researchers have used as a proxy for prostate cancer diagnoses, stayed relatively flat 

from 2006 to 2007 but then decreased by approximately 20 percent from 2007 through 

2010. Others have also noted a decline in reported prostate cancer incidence over a 

similar period. For instance, see: David H. Howard, “Declines in Prostate Cancer 

Incidence After Changes in Screening Recommendations,” Archives of Internal Medicine

172, no. 16 (Sept. 10, 2012): 1267-68.

26Bruce L. Jacobs et al., “Growth of High-Cost Intensity-Modulated Radiotherapy for 

Prostate Cancer Raises Concerns About Overuse,” Health Affairs 31, no. 4 (April 2012): 

750-59.

27In 2010, urologists performed approximately 89.1 percent of office visits billed under 

limited-specialty groups, compared to 5.7 percent for multispecialty groups. Additionally, 

the average number of specialties that billed office visits under limited-specialty groups in 

2010 was 3.3, compared to 36.2 for multispecialty groups.
 

Page 13 GAO-13-525 Medicare Self-Referral of IMRT Services

56,000 to 343,000. In contrast, the number of such services performed by 

multispecialty self-referring groups, which were comprised of a large 

number of different provider types, declined slightly, going from 

approximately 23,000 to 22,000.

Figure 2: Number of Medicare Prostate Cancer–Related IMRT Services Performed 

by Limited-Specialty and Multispecialty Self-Referring Groups, 2006-2010

Notes: In 2006 and 2008, less than 1 percent of total services could not be attributed to either limitedspecialty or multispecialty groups. We defined groups as limited specialty in a given year if more than 

75 percent of its office visits were performed by urologists, nonphysician practitioners (e.g., physician 

assistants), or providers whose specialty was related to the diagnosis or treatment of cancer, such as 

radiation oncologists. The remaining groups were comprised of providers from a large number of 

different specialties and were considered multispecialty groups.
 

Page 14 GAO-13-525 Medicare Self-Referral of IMRT Services

Medicare expenditures for prostate cancer–related IMRT services 

performed by self-referring groups increased rapidly from 2006 through 

2010, while decreasing for services performed by non-self-referring 

groups. Specifically, expenditures for prostate cancer–related IMRT 

services performed by self-referring groups increased from $52 million to 

$190 million, an average increase of 38 percent a year (see fig. 3). In 

contrast, expenditures for prostate cancer–related IMRT services 

performed by non-self-referring groups in physician offices declined by an 

average of 8 percent a year. For comparison, expenditures for prostate 

cancer–related IMRT services performed in hospital outpatient 

departments grew an average of 7 percent a year during the period we 

studied. (For more information about hospital outpatient department 

expenditure trends, see app. II.)

Figure 3: Changes in Medicare Prostate Cancer–Related IMRT Expenditures for 

Services Performed by Self-Referring and Non-Self-Referring Provider Groups in 

Physician Offices, 2006-2010

Expenditures for Prostate 

Cancer–Related IMRT 

Services Performed by 

Self-Referring Groups 

Increased Rapidly, while 

Declining for Non-SelfReferring Groups
 

Page 15 GAO-13-525 Medicare Self-Referral of IMRT Services

Self-referring providers were more likely to refer their Medicare prostate 

cancer patients for IMRT and less likely to refer them for other treatments 

when compared to non-self-referring providers. In addition, after providers 

began self-referring IMRT services, they substantially increased the 

percentage of their prostate cancer patients they referred for IMRT, in 

contrast to providers who did not begin to self-refer IMRT services during 

the same period.

Self-referring providers were more likely to refer their prostate cancer 

patients for IMRT and less likely to refer them for other treatments 

compared to non-self-referring providers. Self-referring providers referred 

approximately 52 percent of their patients who were newly diagnosed with 

prostate cancer in 2009 for IMRT, while non-self-referring providers 

referred 34 percent of their patients for IMRT (see table 2). Self-referring 

providers also referred a lower percentage of their prostate cancer 

patients for nearly all other types of treatments compared to non-selfreferring providers, with the largest differences among patients being 

referred for brachytherapy or a radical prostatectomy.28 Other differences 

were smaller—self-referring providers were about 8 percent less likely to 

refer their patients for active surveillance compared to non-self-referring 

providers. (For alternative groupings in which beneficiaries are sorted into 

discrete treatment categories, see app. III.)

 

28Other than IMRT, the only type of treatment for which self-referring providers did not 

refer a lower percentage of their prostate cancer patients compared to non-self-referring 

providers was proton therapy. 

Self-Referring 

Providers Referred 

Their Prostate Cancer 

Patients for IMRT 

More Frequently than 

Non-Self-Referring 

Providers 

Self-Referring Providers 

Were 53 Percent More 

Likely to Refer Their 

Prostate Cancer Patients 

for IMRT than Non-SelfReferring Providers
 

Page 16 GAO-13-525 Medicare Self-Referral of IMRT Services

Table 2: Percentage of Self-Referring and Non-Self-Referring Providers’ Medicare Patients Referred for a Given Treatment 

after a Diagnosis of Prostate Cancer in 2009

Prostate cancer treatment

Percentage of

non-self-referring 

providers’ patients 

referred for a 

given treatment

(N=48,298)

Percentage of 

self-referring 

providers’ patients 

referred for a 

given treatment

(N=9,991)

Percentage 

point difference

Percentage more or 

less likely self-referring 

providers were to 

refer patients for 

a given treatment 

compared to non-selfreferring providers

Intensity-modulated radiation therapy 33.7% 51.7% 18.0 53.5%

Active surveillance 22.9 21.0 -1.9 -8.2

Radical prostatectomy 18.0 13.1 -4.9 -27.0

Hormone therapy only 11.4 a 7.7 -3.8 -32.9

Brachytherapy 14.0 7.0 -7.0 -50.0

Other treatments 6.0 b 3.2 -2.8 -46.5

Three-dimensional conformal radiation 

therapy / other external beam radiation 

therapy 2.4 1.1 -1.3 -55.2

Source: GAO analysis of CMS data.

Notes: Treatment categories do not sum to 100 percent because, with the exception of active 

surveillance and hormone therapy only, a patient was counted in more than one treatment category if 

he received a combination of therapies. Including combinations involving hormone therapy, selfreferring and non-self-referring providers referred nearly equal percentages of their patients for a 

combination of treatments—27 percent and 26 percent, respectively.

a

Prostate cancer patients also commonly receive hormone therapy in conjunction with other 

treatments. Self-referring providers referred 31.9 percent of their prostate cancer patients for any 

hormone therapy, while non-self-referring providers referred 33.7 percent.

b

The difference between self-referring and non-self-referring providers in 

the percentage of their prostate cancer patients referred for IMRT was 

largely due to self-referring providers who belonged to limited-specialty 

groups. Self-referring providers who belonged to a limited-specialty group 

referred approximately 52 percent of their patients diagnosed with 

prostate cancer in 2007 or 2009 for IMRT.

“Other treatments” consists of cryoablation, stereotactic body radiotherapy / stereotactic 

radiosurgery, and proton therapy. Self-referring providers were less likely to refer their patients for 

cryoablation and stereotactic body radiotherapy / stereotactic radiosurgery compared to non-selfreferring providers, but both types of providers referred the same percentage of their patients for 

proton therapy—approximately 1 percent.

29

 

29Because only a small percentage of beneficiaries were referred by providers who 

belonged to a multispecialty group, we combined beneficiaries diagnosed with prostate 

cancer in 2007 or 2009. Of that population, approximately 92 percent were referred by a 

provider who belonged to a limited-specialty group, compared to 8 percent who were 

referred by a provider who belonged to a multispecialty group.

In contrast, self-referring 
 

Page 17 GAO-13-525 Medicare Self-Referral of IMRT Services

providers who belonged to a multispecialty group referred approximately 

36 percent of their patients diagnosed with prostate cancer in 2007 or 

2009 for IMRT, only moderately higher than the 33 percent of non-selfreferring providers’ patients diagnosed with prostate cancer in 2007 or 

2009 who were referred for IMRT.

Differences in the percentage of prostate cancer patients referred for 

IMRT between self-referring and non-self-referring providers persisted 

after accounting for differences in age, geographic location (i.e., urban or 

rural), and beneficiary health, including clinical characteristics of prostate 

cancers for a subset of beneficiaries who lived in New York.

Differences between self-referring and non-self-referring providers in the 

percentage of prostate cancer patients that were referred for IMRT could 

not be explained by differences in age. The average age when a 

beneficiary was diagnosed with prostate cancer was the same for patients 

of both self-referring and non-self-referring providers, and, regardless of 

their patients’ ages, self-referring providers were more likely to refer their 

patients for IMRT compared to non-self-referring providers. The average 

age when a beneficiary was diagnosed with prostate cancer was 74 years 

old for patients of both self-referring and non-self-referring providers.

Depending on the age range, self-referring providers were anywhere from 

48 percent to 62 percent more likely to refer their patients for IMRT 

compared to non-self-referring providers. For more information about how 

the percentage of prostate cancer patients referred for IMRT and other 

treatments by self-referring and non-self-referring providers changed on 

the basis of the age of a beneficiary, see appendix IV.

Differences between self-referring and non-self-referring providers in the 

percentage of prostate cancer patients that were referred for IMRT could 

not be explained by differences in geographic location. Self-referring 

providers were more likely to refer their patients for IMRT compared to 

non-self-referring providers, regardless of differences in geographic 

location.30

 

30Approximately 84 percent of self-referring providers’ prostate cancer patients lived in 

urban areas compared to approximately 68 percent of non-self-referring providers’ 

patients.

Self-referring providers were 52 percent more likely to refer 

their patients that lived in urban areas for IMRT compared to non-selfreferring providers. Similarly, self-referring providers were 42 percent 

Age 

Geographic Location
 

Page 18 GAO-13-525 Medicare Self-Referral of IMRT Services

more likely to refer their patients that lived in rural areas for IMRT 

compared to non-self-referring providers.

Differences between self-referring and non-self-referring providers in the 

percentage of prostate cancer patients that were referred for IMRT could 

not be explained by differences in beneficiary health. Self-referring and 

non-self-referring providers’ prostate cancer patients had a similar 

average health status, and self-referring providers were more likely to 

refer their patients for IMRT compared to non-self-referring providers, 

regardless of whether their patients had low-, intermediate-, or high-risk 

prostate cancer. Self-referring providers’ patients had an average risk 

score—a proxy for health status—of 0.94 in 2009, and non-self-referring 

providers’ patients had an average risk score of 0.92, indicating that the 

two patient populations had a similar average health status.31 In cases 

where we had information on the clinical characteristics of patients’ 

prostate cancer, we found that self-referring providers were more likely 

than non-self-referring providers to refer their patients for IMRT, although 

the difference decreased as prostate cancer risk level increased.

Specifically, self-referring providers were 91 percent, 41 percent, and 

33 percent more likely than non-self-referring providers to refer patients 

with low-, intermediate-, and high-risk prostate cancer for IMRT, 

respectively.32

 

31A beneficiary’s risk score is a proxy for health status and is equivalent to the ratio of 

expected health care expenditures for the beneficiary under Medicare FFS relative to the 

average health care expenditures for all Medicare FFS beneficiaries. For example, a 

beneficiary with a risk score of 1.05 would have expected expenditures that were 

5 percent higher than an average Medicare FFS beneficiary.

The difference in IMRT referrals made by self-referring and 

non-self-referring providers narrowed as patients’ prostate cancer risk 

level increased in part because non-self-referring providers increased 

IMRT referrals and decreased brachytherapy referrals as cancer risk 

levels increased. In comparison, self-referring providers referred similarly 

small percentages of patients for brachytherapy for all three risk levels, 

32Self-referring providers were also 43 percent more likely to refer their patients for IMRT 

compared to non-self-referring providers for patients who could not be assigned a risk 

category. Because the New York State Cancer Registry contains some cancer 

characteristics obtained after patients received treatment, we also reran this analysis twice 

after restricting the population to patients (1) for whom the extent of the cancer was 

determined before treatment and (2) who did not receive a radical prostatectomy. For both 

of these analyses, the results were similar to the original analysis—self-referring providers 

were between 25 percent and 87 percent more likely to refer their patients for IMRT 

compared to non-self-referring providers, depending on whether the cancer was low, 

intermediate, or high risk.

Beneficiary Health 
 

Page 19 GAO-13-525 Medicare Self-Referral of IMRT Services

and their IMRT referrals increased only moderately as their patients’ risk 

level increased.33

Providers that switched from being non-self-referring to self-referring—

that is, switchers—referred a greater percentage of their prostate cancer 

patients for IMRT after they began to self-refer (see table 3). Specifically, 

switchers referred 37 percent of their patients who were diagnosed with 

prostate cancer in 2007 for IMRT. After beginning to self-refer, switchers 

referred 54 percent of their patients who were diagnosed with prostate 

cancer in 2009 for IMRT. While providers that did not begin to self-refer—

that is, self-referrers and non-self-referrers—referred different 

percentages of their patients who were diagnosed with prostate cancer in 

2007 for IMRT, the percentages of their patients they referred for IMRT 

remained relatively consistent over the same period when switchers 

dramatically increased the percentage of their patients they referred for 

IMRT. This suggests that the increase seen among switchers was likely 

not due to provider characteristics that were relatively stable over time or 

changes in the way all providers treated prostate cancer in response to 

such things as changing treatment guidelines. (See app. V for more 

information about how the percentage of beneficiaries switchers, non-selfreferring providers, and self-referring providers referred for a given 

treatment.)

Table 3: Change in the Percentage of Medicare Prostate Cancer Patients Providers Referred for IMRT after a Diagnosis of 

Prostate Cancer in 2007 or 2009

Type of provider

Percentage of providers’ 

patients referred for IMRT 

among beneficiaries 

diagnosed in 2007

Percentage of providers’ 

patients referred for IMRT 

among beneficiaries 

diagnosed in 2009

Percentage point 

change from 

2007 to 2009

Percentage more or less 

likely providers were to 

refer patients for IMRT in 

2009 compared to 2007

Non-self-referring 31.4% 33.1% 1.7 5.5%

Self-referring 55.7 52.9 -2.8 -5.1

Switcher 37.0 54.2 17.2 46.6

Source: GAO analysis of CMS data.

 

33While the difference between self-referring and non-self-referring providers narrowed, 

non-self-referring providers were still more likely to refer their patients with intermediateand high-risk prostate cancer for brachytherapy compared to self-referring providers. This 

includes brachytherapy as a sole treatment or brachytherapy received in combination with 

another treatment, such as a form of EBRT.

Providers Substantially 

Increased the Percentage

of Their Prostate Cancer 

Patients They Referred for 

IMRT after They Began to 

Self-Refer
 

Page 20 GAO-13-525 Medicare Self-Referral of IMRT Services

Notes: We define switchers as those providers that did not self-refer in 2006 or 2007 but began to 

self-refer in either 2008 or 2009. In 2007, switchers, self-referring providers, and non-self-referring 

providers referred 4,903, 1,776, and 42,471 prostate cancer patients for treatment, respectively. In 

2009, switchers, self-referring providers, and non-self-referring providers referred 4,156, 1,244, and 

34,107 prostate cancer patients for treatment, respectively.

IMRT has been shown to be an effective treatment option for localized 

prostate cancer and allows radiation to be delivered to the tumor while 

minimizing damage to normal tissue. Proponents of self-referral 

arrangements contend that the self-referral of IMRT services does not 

affect clinical decision making and that patients benefit from self-referral 

through, for example, improved coordination among the providers who 

diagnose and treat patients. However, our review indicates that Medicare 

providers that self-referred IMRT services—particularly those practicing in 

limited-specialty groups—were substantially more likely to refer their 

prostate cancer patients for IMRT and less likely to refer them for other, 

less costly treatments, especially brachytherapy or a radical 

prostatectomy, compared to providers who did not self-refer. The 

relatively higher rate of IMRT referrals among self-referring providers 

cannot be explained by beneficiary age, geographic location, or health.

Consistent with these findings, we also found that after providers began 

to self-refer IMRT services they substantially increased the percentage of 

their prostate cancer patients they referred for IMRT, while providers that 

did not begin to self-refer experienced much smaller changes over the 

same period. Taken together, our findings suggest that financial 

incentives were likely a major factor driving the increase of IMRT referrals 

among self-referring providers in limited-specialty groups.

The greater use of IMRT by self-referring Medicare providers to treat 

prostate cancer raises two potential concerns. First, because physician 

recommendations play a large role in influencing a patient’s treatment 

decision, a financial interest in one treatment option may diminish the role 

that other criteria—such as life expectancy, overall health, patient 

preferences, and clinical characteristics of the prostate cancer—play in 

the decision-making process. Despite the fact that several treatment 

options are often considered equally appropriate, the higher use of IMRT 

among providers who self-refer seems problematic because prostate 

cancer treatments differ in terms of their risks and side effects, such as 

the likelihood of developing sexual, urinary, or bowel-related side effects.

To the extent that providers’ financial interests are shaping treatment 

decisions, some patients may end up on a treatment course that does not 

best meet their individual needs. Second, because IMRT costs more than 

most other treatments, the higher use of IMRT by self-referring providers 

Conclusions 
 

Page 21 GAO-13-525 Medicare Self-Referral of IMRT Services

results in higher costs for Medicare and beneficiaries. To the extent that 

treatment decisions are driven by providers’ financial interest and not by 

patient preference, these increased costs are difficult to justify.

Given self-referral’s potential effect on both the Medicare program and 

beneficiaries, it is imperative that CMS improve its ability to identify and 

monitor the effects of such services. CMS is not currently well-positioned 

to address self-referring providers’ financial incentive to refer their 

prostate cancer patients for IMRT, as CMS currently does not have a 

method for easily identifying such services. Without a way to identify selfreferred services, such as a self-referral flag on Medicare Part B claims, 

CMS does not have the ongoing ability to monitor self-referral and its 

effects on beneficiary treatment selection and costs to both Medicare and 

beneficiaries.

In addition, Medicare providers who self-refer IMRT services are 

generally not required to disclose their financial interest in IMRT. Thus, 

beneficiaries may not be aware that their provider has an incentive to 

recommend IMRT over alternative treatments which may be equally 

effective, have different risks and side effects, and are less expensive for 

Medicare and beneficiaries. Beneficiaries need to select among different 

prostate cancer treatment options, and beneficiary knowledge of a 

referring provider’s financial interest in IMRT may be an important 

consideration in making these selections. Currently, the Department of 

Health and Human Services (HHS), the agency that administers CMS, 

lacks the authority to establish a disclosure protocol for providers who 

self-refer IMRT services.

To increase beneficiaries’ awareness of providers’ financial interest in a 

particular treatment, Congress should consider directing the Secretary of 

Health and Human Services to require providers who self-refer IMRT 

services to disclose to their patients that they have a financial interest in 

the service.

We recommend that the Administrator of CMS insert a self-referral flag on 

its Medicare Part B claims form, require providers to indicate whether the 

IMRT service for which a provider bills Medicare is self-referred, and 

monitor the effects that self-referral has on costs and beneficiary 

treatment selection.

Matter for 

Congressional 

Consideration 

Recommendation for 

Executive Action
 

Page 22 GAO-13-525 Medicare Self-Referral of IMRT Services

We provided a draft of this report to HHS for comment. HHS provided 

written comments, which are reprinted in appendix VI. We also obtained 

oral comments from representatives of three professional associations 

selected because they represent stakeholders with specific involvement 

in prostate cancer–related IMRT services.

The three associations were the American Society for Radiation Oncology 

(ASTRO), which represents radiation oncologists; the American 

Urological Association (AUA), which represents urologists; and the Large 

Urology Group Practice Association (LUGPA), which represents large 

urology group practices. We summarize and respond to comments from 

HHS and representatives from the three professional associations in the 

following sections. 

In its comments, which are reprinted in appendix VI, HHS stated that it did 

not concur with our recommendation. HHS did not comment on the matter 

for congressional consideration or the main finding of the report—that 

self-referring providers, particularly those belonging to limited-specialty 

groups, referred a substantially higher percentage of their prostate cancer 

patients for IMRT.

HHS did not concur with our recommendation that CMS insert a selfreferral flag on its Medicare Part B claims form, require providers to 

indicate whether the IMRT service for which a provider bills Medicare is 

self-referred, and monitor the effects that self-referral has on costs and 

beneficiary treatment selection. HHS stated that flagging self-referred 

services and tracking their effects would not address overutilization that 

occurs as a result of self-referral, would be complex to administer, and 

may have unintended consequences, which HHS did not delineate. In 

addition, HHS stated that the President’s fiscal year 2014 budget 

proposal includes a provision to exclude certain services from the in-office 

ancillary services (IOAS) exception. To the extent that self-referral for 

IMRT services continues to be permitted, we believe that including an 

indicator or flag on the claims would be an effective way to identify and 

track self-referral and would give CMS the ability to analyze the effects of 

self-referral on utilization patterns. Furthermore, we do not believe an 

indicator or flag on the claims would be complex to administer, as CMS 

requires providers to use similar indicators to provide additional 

information about certain other services. 

Agency and ThirdParty Comments and 

Our Evaluation

HHS Comments
 

Page 23 GAO-13-525 Medicare Self-Referral of IMRT Services

On the basis of HHS’s written response to our report, we are concerned 

that HHS does not appear to recognize the effects IMRT self-referral can 

have on beneficiaries and the Medicare program. HHS did not comment 

on our matter for congressional consideration or our key finding that selfreferring providers, particularly those belonging to limited specialty 

groups, referred a substantially higher percentage of their prostate cancer 

patients for IMRT. Given the magnitude of these findings, we continue to 

believe that CMS should take steps to monitor the impact that IMRT selfreferral has on costs and treatment selection.

HHS also provided technical comments that we incorporated as

appropriate.

ASTRO representatives generally agreed with our findings but thought 

our recommendation and matter for congressional consideration should 

be stronger. They said we should recommend that Congress close the 

IOAS exception because the findings from the report, in combination with 

previous self-referral research we and others have published, indicate the 

necessity for such an action. An examination of the IOAS was beyond the 

scope of our work. To the extent that IMRT self-referral is still permissible, 

ASTRO representatives also said that inserting a self-referral flag would 

not be an effective way to identify self-referral. Instead, they suggested 

implementing reporting requirements similar to the financial transparency 

requirements for physician-owned specialty hospitals under PPACA and 

requiring self-referring providers to indicate on their Medicare provider 

enrollment forms their financial interest in referrals. Further, ASTRO 

representatives said that self-referring providers should be required to 

notify patients that they may receive IMRT at alternative locations and 

that other treatment options are available. We continue to believe that 

inserting a self-referral flag on Medicare Part B claims would be an

effective way to track and monitor self-referral and that beneficiary 

awareness of their providers’ financial interests is important. However, to 

the extent that other strategies exist that would allow CMS to increase 

beneficiary awareness and monitor self-referral, such efforts would be 

consistent with the intent of our recommendation and matter for 

congressional consideration.

Professional Association 

Comments 

American Society for Radiation 

Oncology
 

Page 24 GAO-13-525 Medicare Self-Referral of IMRT Services

AUA representatives said we did not have sufficient evidence to link 

financial incentives to the increase in IMRT use among self-referring 

providers and disagreed with our conclusion that financial incentives for 

self-referring providers belonging to limited specialty groups were likely a 

major factor driving the increase in the percentage of prostate cancer 

patients referred for IMRT. Specifically, AUA representatives said the flat 

trend in the utilization of prostate cancer-related IMRT services from 2007 

through 2010 indicates utilization has simply shifted from hospital 

outpatient departments to physician offices and that this trend 

undermines our conclusion that financial incentives increase IMRT use. 

As explained in our report, the trend in the percentage of patients newly 

diagnosed with prostate cancer referred for IMRT was not flat; instead, it 

increased over the study period. This increase occurred while the 

utilization of IMRT services remained about the same in part because the 

annual number of Medicare FFS beneficiaries who were diagnosed with 

prostate cancer declined by about 20 percent over our study period. In 

addition, we found that self-referring providers, which were predominantly 

from limited-specialty groups, referred a higher percentage of their 

Medicare FFS patients for IMRT than did other providers and that their 

higher IMRT referral rate could not be explained by differences in age, 

geographic location, or beneficiary health. As a result, we continue to 

believe that financial incentives were likely a major factor driving the 

higher IMRT referral rate of self-referring providers from limited-specialty 

groups.

AUA representatives had several other critiques of our report.

Specifically, they indicated that we did not put enough emphasis on the 

patient’s role in choosing a treatment and expressed concern that we did 

not include more clinical information on patients’ prostate cancer, such as 

information on cancer stage and grade, or include Medicare Advantage 

beneficiaries in our study population. We address two of these critiques in 

the report. Specifically, we note that patient preference is one of many 

factors that affect a beneficiary’s treatment decision, and we include 

clinical information on patients’ prostate cancer for a subset of 

beneficiaries from New York.34

 

34We used clinical information from the New York State Cancer Registry because such 

information is not available on Medicare claims, and we determined that the geographic 

areas included in another common source of such information—Surveillance 

Epidemiology and End Results (SEER) data—did not sufficiently overlap with areas in 

which IMRT self-referral was prevalent during our study period.

However, we did not include Medicare 

American Urological 

Association
 

Page 25 GAO-13-525 Medicare Self-Referral of IMRT Services

Advantage beneficiaries in our study population because Medicare 

Advantage plans are not required to submit claims to CMS, and, thus, we 

do not have detailed information on the services Medicare Advantage 

beneficiaries receive or the providers who refer and perform those 

services. 

Finally, AUA representatives stated that the declining percentage of selfreferring providers’ patients referred for brachytherapy from 2007 to 2009 

could reflect a change in practice standards, as they said brachytherapy 

is no longer recommended as a sole treatment for intermediate- and highrisk prostate cancer. While we note that brachytherapy use has declined 

even among providers who do not self-refer, we do not believe that 

changing guidelines or the possibility of differences in guideline 

adherence between non-self-referring and self-referring providers could 

explain in totality why self-referring providers refer a smaller percentage

of their patients for brachytherapy. First, self-referring providers referred a 

substantially lower percentage of their patients for brachytherapy, even 

after accounting for the decline in brachytherapy use for both non-selfreferring and self-referring providers from 2007 to 2009. Second, among 

those patients for whom we had clinical data, the biggest differences in 

IMRT and brachytherapy use between self-referring and non-self-referring 

providers were for patients with low-risk cancer, which would not be 

affected by the change in practice guidelines for intermediate- and highrisk prostate cancer the AUA representatives referenced.

LUGPA representatives disagreed with our conclusion that financial 

incentives for self-referring providers—specifically those in limitedspecialty groups—were likely a major factor driving the increase in the 

percentage of prostate cancer patients referred for IMRT. Instead, they 

said patient preference and an increase in the number of self-referring 

providers explain the increase in IMRT utilization by self-referring 

providers. While we did not perform our trend analysis at the provider 

level, we do note in the report that the number of self-referring groups 

increased substantially over our study period. This corresponds with a 

shift in the location where patients received IMRT, from hospital 

outpatient departments to physician offices. However, these trends that 

we note do not negate our analysis of the referral patterns of self-referring 

providers. Specifically, self-referring providers who belonged to a limitedspecialty group referred a higher percentage of their newly diagnosed 

prostate cancer patients for IMRT, and, thus, the increased number of 

Large Urology Group Practice 

Association
 

Page 26 GAO-13-525 Medicare Self-Referral of IMRT Services

self-referring providers has also resulted in a higher percentage of 

patients receiving IMRT. Also, LUPGA representatives said the increase 

in the percentage of self-referring providers’ patients referred for IMRT 

could be due to such patients more frequently consulting with radiation 

oncologists before initiating treatment, which one study indicated leads to 

higher utilization of radiation therapy, defined as EBRT or 

brachytherapy.35

LUGPA raised several other points of concern about our review. First, 

LUGPA representatives said our assertion that IMRT, brachytherapy, and 

a prostatectomy are clinically equivalent treatments is inappropriate. We 

disagree with LUGPA’s characterization of our discussion of IMRT, 

brachytherapy, and a prostatectomy as treatment options. We recognize 

that these treatments are not equally appropriate for all men diagnosed 

with prostate cancer and do not assert that in our report. Rather, we say 

that these treatments are often—not always—considered equally 

appropriate and give an example of when they are considered equally 

appropriate—men with low-risk prostate cancer. We also recognize that, 

for any particular patient, a given treatment might not be appropriate due 

to considerations such as age and comorbidities. Second, LUGPA 

representatives said that we did not acknowledge that all sites of services 

have essentially identical financial incentives to perform services for 

which they receive compensation. They said our work showed the 

percentage of newly diagnosed prostate cancer patients referred for 

active surveillance was nearly equal between self-referring and non-selfreferring providers and that this was evidence that self-referring providers 

treat patients based on patient choice and sound clinical decision making. 

We disagree with LUGPA's assertion that the percentage of newly 

We believe it is unlikely that access to a radiation 

oncologist drove the differences in IMRT referrals between self-referring 

and non-self-referring providers because self-referring providers who 

belonged to a multispecialty group referred a substantially lower 

percentage of their patients for IMRT compared to self-referring providers 

who belonged to a limited-specialty group, despite the likelihood that 

patients in both instances had access to a radiation oncologist within the 

group practice.

 

35Thomas L. Jang et al., “Physician Visits Prior to Treatment for Clinically Localized

Prostate Cancer,” Archives of Internal Medicine 172, no.5 (March 8, 2010): 440-450.
 

Page 27 GAO-13-525 Medicare Self-Referral of IMRT Services

diagnosed prostate cancer patients referred for active surveillance was 

nearly equal between self-referring and non-self-referring providers, as 

self-referring providers were approximately 8 percent less likely to refer 

their patients for active surveillance than were non-self-referring 

providers. As we note in the report, IMRT is more costly than other 

treatments for prostate cancer, resulting in a financial incentive for selfreferring providers to refer their patients for IMRT over other treatments. 

We found that self-referring providers referred a higher percentage of 

their patients for IMRT than did non-self-referring providers and that the 

difference in IMRT referral rates could not be explained by variations in 

patient age, geographic location, or patient health status. As a result, we 

continue to believe that self-referring providers’ higher IMRT referral rates 

are driven by a financial incentive for these providers to refer newly 

diagnosed prostate cancer patients for IMRT. Third, LUGPA 

representatives said we should have studied the use of IMRT for 

conditions other than prostate cancer. The use of IMRT to treat other 

conditions was outside the scope of our work. Finally, LUGPA 

representatives indicated that our estimates of 3D-CRT utilization for 

newly diagnosed prostate cancer patients are too low. We believe our 

calculation of the percentage of patients who were newly diagnosed with 

prostate cancer in 2009 and referred for 3D-CRT is accurate. We solicited 

input from multiple physician associations, including members of LUGPA, 

regarding the appropriate HCPCS codes to use to track 3D-CRT and 

examined 100 percent of claims from the Medicare Carrier and hospital 

outpatient department files to identify all 3D-CRT services received by 

newly diagnosed prostate cancer patients.

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. At that time, we will send copies to the Secretary of Health 

and Human Services, interested congressional committees, and others.

In addition, the report will be available at no charge on the GAO website 

at http://www.gao.gov. 
 

Page 28 GAO-13-525 Medicare Self-Referral of IMRT Services

If you or your staff has any questions about this report, please contact me 

at (202) 512-7114 or cosgrovej@gao.gov. Contact points for our Offices 

of Congressional Relations and Public Affairs may be found on the last 

page of this report. GAO staff who made major contributions to this report 

are listed in appendix VII. 

James C. Cosgrove

Director, Health Care
Page 29 GAO-13-525 Medicare Self-Referral of IMRT Services

List of Requesters

The Honorable Max Baucus

Chairman

Committee on Finance

United States Senate

The Honorable Chuck Grassley

Ranking Member

Committee on the Judiciary

United States Senate

The Honorable Henry A. Waxman

Ranking Member

Committee on Energy and Commerce

House of Representatives

The Honorable Sander Levin

Ranking Member

Committee on Ways and Means

House of Representatives
Appendix I: Scope and Methods

Page 30 GAO-13-525 Medicare Self-Referral of IMRT Services

This section describes the scope and methodology used to analyze our 

two objectives: (1) comparing trends in the number of and expenditures 

for Medicare prostate cancer–related intensity-modulated radiation 

therapy (IMRT) services provided by self-referring and non-self-referring 

groups from 2006 through 2010 and (2) examining how the percentage of 

Medicare prostate cancer patients referred for IMRT may differ on the 

basis of whether providers self-refer.

To compare trends in the number of and expenditures for prostate 

cancer–related IMRT services provided in physician offices or hospital 

outpatient departments from 2006 through 2010, we analyzed IMRT 

claims from the Medicare Part B Carrier and hospital outpatient files.1 We 

identified IMRT services on the basis of Healthcare Common Procedure 

Coding System (HCPCS) codes associated with the delivery of IMRT—

77418 and 0073T.2

To determine whether prostate cancer–related IMRT services from 2006 

through 2010 were performed by self-referring or non-self-referring 

provider groups, we first limited our analysis to only those IMRT services 

in the Medicare Part B Carrier file.

We classified IMRT services as related to prostate 

cancer if the principal diagnosis code was 185 or 233.4—malignant 

neoplasm of the prostate or carcinoma in situ of prostate, respectively—or 

if one of these codes was billed on an IMRT claim and no other diagnosis 

code related to another cancer was billed on the same claim.

3

 

1

We also used the Part B National Summary Data Files to track the total number of 

prostate biopsies from 2006 through 2010. The Medicare Part B Carrier File contains final 

action Medicare Part B claims for noninstitutional providers, such as physicians. The 

Medicare hospital outpatient file contains final action, fee-for-service claims data 

submitted by institutional outpatient providers, such as hospital outpatient departments. 

Because there is no indicator or “flag” 

on the claim that identifies whether services are self-referred or non-selfreferred and the Centers for Medicare & Medicaid Services (CMS), the 

2

Medicare expenditure amounts for these codes include beneficiary cost sharing 

throughout this report. IMRT delivery codes represent individual treatment sessions during 

which patients receive radiation. In addition to receiving radiation, patients receive several 

different types of services during a course of IMRT.

3

Our analysis of self-referred prostate cancer–related IMRT services is limited to those 

services performed in physician offices. We focused on this setting because our work 

showed rapid growth in this setting compared to hospital outpatient departments and 

because the financial incentive for providers to self-refer is most direct when the service is 

performed in a physician office. We refer to services billed through the Carrier file as 

services performed in physician offices.

Appendix I: Scope and Methods
Appendix I: Scope and Methods

Page 31 GAO-13-525 Medicare Self-Referral of IMRT Services

agency that administers Medicare, has no other method for identifying 

whether a service was self-referred, we developed a claims-based 

methodology for identifying provider group practices as self-referring or 

non-self-referring.4 We classified groups, identified by taxpayer 

identification numbers (TIN)—an identification number used by the 

Internal Revenue Service—as self-referring in a given year if: (1) we

could identify a prostate biopsy for at least 50 percent of the prostate 

cancer–related IMRT episodes provided by groups,5 (2) at least 

50 percent of these episodes were self-referred, and (3) a group had a 

minimum number of 10 self-referred IMRT episodes.6 The remaining 

groups were considered non-self-referring.7 To ensure that how we 

defined our criteria were reliable, we tested alternative thresholds for 

defining self-referring groups and found that, regardless of specification, 

the rapid growth of services performed by self-referring groups persisted 

and that the growth was due to limited-specialty groups. A patient’s 

episode of prostate cancer–related IMRT was considered self-referred if 

the provider who performed his prostate biopsy and the performing 

provider(s) on the IMRT claim(s) billed to the same TIN in the year(s) the 

IMRT services were performed, the year the biopsy was performed, or the 

year between, if applicable.8

 

4

An indicator or “flag” could be, for example, a modifier that a provider lists on a claim to 

indicate that a service is self-referred. Providers currently use modifiers to provide 

additional information about a service to CMS.

To find prostate biopsies for beneficiaries, 

we searched through 2 years of their claims history to find the prostate 

biopsy nearest to, but not after, the date of their first IMRT service. If a 

beneficiary received multiple episodes of IMRT from 2006 through 2010, 

5

From 2006 through 2010, beneficiaries could receive multiple episodes of prostate 

cancer–related IMRT. We defined an episode of IMRT as a contiguous group of IMRT 

services not separated by more than 7 days. If a beneficiary had more than one prostatecancer related IMRT episode over the course of our study, we classified each episode as 

self-referred or non-self-referred separately.

6

Respectively, these restrictions were made to ensure that we (1) did not classify groups 

as self-referring on the basis of a small percentage of the IMRT episodes they provided, 

(2) classified groups on the basis of the predominant way in which the group practiced, 

and (3) had an adequate number of IMRT episodes to accurately categorize groups.

7

Services performed by non-self-referring groups in the physician office setting could 

include services provided in places such as freestanding cancer centers.

8

Self-referral occurs when providers refer their patients to entities—such as themselves or 

a group practice—in which they or a member of their families has a financial relationship. 

We used TINs to identify financial relationships between the provider who performed the 

prostate biopsy and the provider(s) who administered IMRT.
Appendix I: Scope and Methods

Page 32 GAO-13-525 Medicare Self-Referral of IMRT Services

we searched back 2 years from the date of the first IMRT service for each 

episode. We further defined self-referring provider groups as either 

limited-specialty or multispecialty groups. We defined groups as limited 

specialty if more than 75 percent of its office visits in a given year were 

performed by urologists, nonphysician practitioners, or physicians whose 

specialty was related to the diagnosis or treatment of cancer, such as 

radiation oncologists. The remaining self-referring groups were comprised 

of providers from a large number of different specialties and were 

considered multispecialty groups.

To examine how the percentage of prostate cancer patients referred for 

IMRT may differ on the basis of whether providers self-refer, we first 

identified a list of Medicare beneficiaries who were newly diagnosed with 

prostate cancer in 2007 or 2009. We used a Medicare claims-derived 

date from the Chronic Condition Data Warehouse (CCDW), a CMS 

database, that indicates the first occurrence of prostate cancer as a proxy 

for the date on which a beneficiary was diagnosed with prostate cancer.

We further narrowed the list of prostate cancer patients we studied to 

those who (1) were at least 66 years of age on their date of diagnosis, 

(2) were continuously enrolled in Medicare Parts A and B in the year of, 

before, and after they were diagnosed,9 and (3) received a prostate 

biopsy on the same day as or within 1 year prior to their diagnosis.10 We 

then analyzed prostate cancer–related claims from the Medicare Part B 

Carrier and hospital outpatient files to determine what types of treatments 

these beneficiaries received from their diagnosis date through 1 year after 

that date.11

 

9

This requirement includes not being enrolled in Medicare Advantage in the year of, 

before, or after a beneficiary’s prostate cancer diagnosis.

We used the provider who performed a beneficiary’s prostate 

biopsy that was nearest to his date of diagnosis as a proxy for the 

provider who referred the beneficiary for treatment. We classified referring 

10These restrictions removed beneficiaries for whom the diagnosis date could have been 

unrelated to when they were actually diagnosed with prostate cancer. For instance, a 

65-year-old beneficiary could have been diagnosed with prostate cancer before aging onto 

Medicare, and, therefore, the claims-based diagnosis date could have represented when 

the beneficiary became eligible for Medicare rather than when he was first diagnosed.

11We did not determine whether treatments were curative or palliative. We also did not 

differentiate on the basis of the order of different treatment combinations or the duration of 

treatments. A prostate cancer patient was considered to have undergone active 

surveillance if he—in addition to meeting the general inclusion criteria—did not receive a 

service indicating that he received any other prostate cancer treatment within one year of 

diagnosis.
Appendix I: Scope and Methods

Page 33 GAO-13-525 Medicare Self-Referral of IMRT Services

providers as self-referring if they were the performing provider on a claim 

that was paid to a self-referring provider group in the year of, before, or 

after a beneficiary’s prostate cancer diagnosis. All other providers were 

considered non-self-referring. Similarly, we classified providers as 

belonging to a limited-specialty group if they were the performing provider 

on a claim that was paid to a limited-specialty provider group in the year 

of, before, or after a beneficiary’s prostate cancer diagnosis. If a provider 

did not belong to a limited-specialty group, we considered the provider to 

belong to a multispecialty group.

To assess the possibility that beneficiary characteristics affected the 

types of treatments for which self-referring and non-self-referring 

providers referred their prostate cancer patients, we examined 

beneficiaries’ (1) age at the time they were diagnosed with prostate 

cancer, (2) geographic location (i.e., urban or rural), and (3) health, 

including clinical characteristics of prostate cancers for a subset of 

beneficiaries who lived in New York. We determined a beneficiary’s age 

at diagnosis using a beneficiary’s date of birth and the date on which he 

was diagnosed with prostate cancer. We defined urban settings as 

metropolitan statistical areas, a geographic entity defined by the Office of 

Management and Budget as a core urban area of 50,000 or more 

population. We used rural-urban commuting area codes—a Census tract–

based classification scheme that utilizes the standard Bureau of Census 

Urbanized Area and Urban Cluster definitions in combination with workcommuting information to characterize all of the nation’s Census tracts 

regarding their rural and urban status—to identify beneficiaries as living in 

metropolitan statistical areas.12 We considered all other settings to be 

rural. We used CMS’s risk score file to identify average risk score, which 

serves as a proxy for beneficiary health status. For a subset of 

beneficiaries who lived in New York, we obtained clinical information on 

the beneficiaries’ prostate cancer—including information used to 

determine whether the localized cancer was low, intermediate, or high 

risk—from the New York State Cancer Registry.13

 

12We considered a location with a rural-urban commuting area code of 1.0, 1.1, 2.0, 2.1, 

or 3.0 to be a metropolitan statistical area.

To establish whether a 

prostate cancer was low, intermediate, or high risk, we used a 

beneficiary’s Gleason score, prostate-specific antigen (PSA), and tumor 

13This analysis includes beneficiaries who were diagnosed with prostate cancer in either 

2007 or 2009.
Appendix I: Scope and Methods

Page 34 GAO-13-525 Medicare Self-Referral of IMRT Services

stage from the New York State Cancer Registry.14

We also determined whether the percentage of a provider’s prostate 

cancer patients referred for IMRT changed after providers began to selfrefer. Specifically, we identified a group of providers, which we called 

“switchers,” that did not self-refer in 2006 or 2007 but began to self-refer 

in either 2008 or 2009. We then calculated the change in the percentage

of switchers’ patients referred for IMRT and other treatments among 

those diagnosed with prostate cancer in 2007 and 2009. We then 

compared the change among switchers to the change experienced by 

providers that did not change whether or not they self-referred IMRT 

services from 2007 to 2009. Specifically, we compared the change in the 

percentage of switchers’ prostate cancer patients they referred for IMRT 

to the percentage of patients referred for IMRT by (1) self-referring 

providers—providers that self-referred in 2007, 2008, and 2009 and either 

self-referred or did not bill Medicare in 2006 and 2010 and (2) non-selfreferring providers—providers that did not self-refer in 2007, 2008, and 

2009 and either did not self-refer or did not bill Medicare in 2006 and 

2010.

The results of the New 

York analysis are not generalizable to the entire Medicare population.

15

We took several steps to ensure that the data used to produce this report 

were sufficiently reliable. Specifically, we assessed the reliability of the 

CMS data we used by interviewing officials responsible for overseeing 

these data sources, including CMS and Medicare contractor officials. We 

also reviewed relevant documentation and examined the data for obvious 

errors, such as missing values and values outside of expected ranges. 

We determined that the data were sufficiently reliable for the purposes of 

our study.

 

14Such information is not available on Medicare claims. Researchers commonly use the 

National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) data to 

obtain clinical information about Medicare patients who were diagnosed with cancer. We 

did not use SEER data because we examined treatments received by men diagnosed with 

prostate cancer in 2007 and 2009, and, in 2007, IMRT self-referral was concentrated in 

states not included in SEER data. Respectively, low-, intermediate-, and high-risk prostate 

cancers were defined as follows: T1-T2a, Gleason score 2-6, and PSA < 10 ng/ml; T2bT2c, Gleason score 7, or PSA 10-20 ng/ml; and T3a, Gleason score 8-10, or PSA > 

20 ng/ml.

15For this analysis and our analysis of all providers who referred a Medicare beneficiary in 

our study who was diagnosed with prostate cancer in 2007 or 2009, we counted IMRT and 

other treatments regardless of the setting in which they were performed.
Appendix I: Scope and Methods

Page 35 GAO-13-525 Medicare Self-Referral of IMRT Services

We conducted this performance audit from May 2010 through July 2013 

in accordance with generally accepted government auditing standards.

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our 

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.
Appendix II: Change in Prostate Cancer–

Related IMRT Services and Expenditures by 

Setting

Page 36 GAO-13-525 Medicare Self-Referral of IMRT Services

Medicare prostate cancer–related intensity-modulated radiation therapy 

(IMRT) utilization varied substantially between settings (see fig. 4). From 

2006 through 2010, utilization grew at an annual rate of 10 percent in 

physician offices, whereas there was almost no growth in the hospital 

outpatient department. Moreover, while the utilization of prostate cancer–

related IMRT services in the hospital outpatient department was nearly 

the same in 2006 as it was in 2010, utilization in this setting actually 

peaked in 2007 and declined thereafter.

Figure 4: Number of Medicare Prostate Cancer–Related IMRT Services by Setting, 

2006-2010

Total prostate cancer–related IMRT expenditures grew from $589 million 

to $698 million over our study period, but growth rates varied by setting 

(see fig. 5). In contrast to the growth in utilization, expenditures increased 

faster for services performed in hospital outpatient departments than 

those performed in physician offices—7 percent and 3 percent annual 

growth rates, respectively. This is due to the fact that reimbursement 

rates for IMRT services have been increasing for services performed in 

hospital outpatient departments and declining for those performed in 

physician offices.

Appendix II: Change in Prostate Cancer–

Related IMRT Services and Expenditures by 

Setting 
Appendix II: Change in Prostate Cancer–

Related IMRT Services and Expenditures by 

Setting

Page 37 GAO-13-525 Medicare Self-Referral of IMRT Services

Figure 5: Expenditures for Medicare Prostate Cancer–Related IMRT Services by 

Setting, 2006-2010
Appendix III: Discrete Prostate Cancer 

Treatment Categories

Page 38 GAO-13-525 Medicare Self-Referral of IMRT Services

The higher percentage of patients that self-referring Medicare providers 

referred for intensity-modulated radiation therapy (IMRT) compared to 

non-self-referring providers was due to self-referring providers referring 

their patients for IMRT only and IMRT in conjunction with hormone 

therapy more often (see table 4). Including all combinations, self-referring 

and non-self-referring providers referred nearly equal percentages of their 

patients for a combination of treatments—27 percent and 26 percent, 

respectively.

Table 4: Percentage of Self-Referring and Non-Self-Referring Providers’ Medicare Patients Referred for a Given Treatment or 

Combination of Treatments after Diagnosis of Prostate Cancer in 2009

Prostate cancer treatment

Percentage of non-selfreferring providers’ patients

referred for a given treatment

(N=48,298)

Percentage of self-referring 

providers’ patients referred 

for a given treatment

(N=9,991)

Percentage 

point difference

IMRT only 12.8% 27.0% 14.2

IMRT and radical prostatectomy 1.2 0.9 -0.3

IMRT and brachytherapy 4.7 2.6 -2.0

IMRT and hormone therapy 13.2 20.1 6.9

Active surveillance 22.9 21.0 -1.9

Radical prostatectomy only 15.5 11.5 -4.0

Radical prostatectomy and hormone therapy 1.1 0.6 -0.5

Hormone therapy only 11.4 7.7 -3.8

Brachytherapy only 6.5 3.5 -3.0

Brachytherapy and hormone therapy 2.2 0.7 -1.5

Other treatments only 4.4 a 2.5 -2.0

Other treatments and hormone therapy 1.3 0.6 -0.7

Three-dimensional conformal radiation therapy(3D-CRT) 

/ other external beam radiation therapy (EBRT) only 0.2 0.0 -0.1

3D-CRT / other EBRT and hormone therapy 0.3 0.1 -0.2

Other combinations 2.2 b 1.1 -1.1

Source: GAO analysis of CMS data.

Notes: Percentages do not sum to 100 percent due to rounding. Beneficiaries were sorted into “IMRT 

and brachytherapy” and “IMRT and radical prostatectomy” if they received IMRT plus the treatment or 

IMRT plus the treatment and hormone therapy. Beneficiaries sorted into “IMRT and hormone therapy” 

did not receive any other treatments. Men were considered to have received a combination of 

therapies if they received at least one service from two or more different types of treatments. We did 

not differentiate on the basis of the order of different treatment combinations or the duration of 

treatments. 

a

b

“Other combinations” includes any combination of treatments that does not have a separate 

category, such as 3D-CRT / other EBRT and brachytherapy.

“Other treatments” consists of cryoablation, stereotactic body radiotherapy / stereotactic 

radiosurgery, and proton therapy.

Appendix III: Discrete Prostate Cancer 

Treatment Categories
Appendix IV: Distribution of Prostate Cancer 

Treatments by Age

Page 39 GAO-13-525 Medicare Self-Referral of IMRT Services

While self-referring Medicare providers were more likely to refer their 

prostate cancer patients for intensity-modulated radiation therapy (IMRT) 

regardless of age, the type of treatment they were less likely to refer their 

patients for varied based on the age of the beneficiary (see table 5). For 

instance, among beneficiaries 80 years of age or older at the time they 

were diagnosed with prostate cancer, self-referring providers were less 

likely to refer their prostate cancer patients for hormone therapy only, 

active surveillance, and brachytherapy compared to non-self-referring 

providers. In contrast, among beneficiaries 66 to 69 years old, nearly the 

entire difference between self-referring and non-self-referring providers 

was due to self-referring providers referring a smaller percentage of their 

prostate cancer patients for a radical prostatectomy or brachytherapy.

Table 5: Percentage of Self-Referring and Non-Self-Referring Providers’ Medicare Patients Referred for a Given Treatment 

after a Diagnosis of Prostate Cancer in 2009 by Age of Beneficiary

Age category (in years)

Percentage of non-self-referring 

providers’ patients referred for a given 

treatment by age category (years)

Percentage of self-referring providers’

patients referred for a given treatment 

by age category (years)

Prostate cancer

treatment

66-69

(N=12,988)

70-74

(N=16,710)

75-79

(N=11,025)

≥80

(N=7,575)

66-69

(N=2,636)

70-74

(N=3,434)

75-79

(N=2,340)

≥80

(N=1,581)

IMRT 29.1% 36.3% 40.7% 25.7% 46.6% 54.5% 60.1% 41.8%

Active surveillance 18.1 20.7 25.9 31.4 16.1 20.1 22.4 29.0

Radical prostatectomy 35.8 20.5 5.1 0.6 28.3 14.1 3.2 0.4

Hormone therapy only 4.1 6.2 11.8 35.0 2.7 3.9 7.1 25.1

Brachytherapy 15.5 16.6 14.4 5.2 8.9 8.4 6.2 2.0

Other treatments 5.2 a 6.7 7.4 3.9 3.2 3.3 3.6 2.7

Three-dimensional 

conformal radiation 

therapy / other external 

beam radiation therapy 2.2 2.7 2.9 1.8 1.0 1.1 1.3 1.0

Source: GAO analysis of CMS data.

Notes: Treatment categories do not sum to 100 percent because, with the exception of active 

surveillance and hormone therapy only, the categories are not mutually exclusive.

a

“Other treatments” consists of cryoablation, stereotactic body radiotherapy/ stereotactic radiosurgery, 

and proton therapy.

Appendix IV: Distribution of Prostate Cancer 

Treatments by Age
Appendix V: Change in Prostate Cancer 

Treatment Patterns over Time for Different 

Types of Providers

Page 40 GAO-13-525 Medicare Self-Referral of IMRT Services

The increased percentage of Medicare patients referred by switchers for 

intensity-modulated radiation therapy (IMRT) was accompanied by a 

decrease in the percentage of patients referred for several other 

treatments, especially brachytherapy (see table 6). Some of the changes 

in the percentage of patients referred by switchers for a given treatment 

were consistent with the patterns for other types of providers—such as in 

the case of three-dimensional conformal radiation therapy (3D-CRT) / 

other external beam radiation therapy (EBRT)—while some of the other 

changes were not.

Table 6: Change in the Percentage of Medicare Prostate Cancer Patients Providers Referred for a Given Treatment after a 

Diagnosis of Prostate Cancer in 2007 or 2009 

Prostate 

cancer treatment Type of provider

Percentage of 

providers’ patients 

referred for a given 

treatment among 

beneficiaries 

diagnosed in 2007

Percentage of 

providers’ patients 

referred for a given 

treatment among 

beneficiaries 

diagnosed in 2009

Percentage point 

change from 

2007 to 2009

Percentage more or 

less likely providers 

were to refer patients 

for a given treatment in 

2009 compared to 2007

IMRT Non-self-referring 31.4% 33.1% 1.7 5.5%

Self-referring 55.7 52.9 -2.8 -5.1

Switcher 37.0 54.2 17.2 46.6

Active surveillance Non-self-referring 19.3 22.6 3.3 17.3

Self-referring 17.3 20.7 3.4 19.6

Switcher 18.1 20.1 2.0 11.2

Brachytherapy Non-self-referring 17.6 14.4 -3.2 -18.2

Self-referring 4.7 2.3 -2.5 -52.4

Switcher 20.7 9.9 -10.8 -52.2

Radical 

prostatectomy

Non-self-referring 16.6 18.0 1.4 8.5

Self-referring 13.1 15.1 2.0 15.7

Switcher 13.0 11.1 -1.9 -14.5

Hormone therapy 

only

Non-self-referring 14.3 11.6 -2.7 -18.6

Self-referring 8.6 7.9 -0.7 -8.6

Switcher 13.1 8.0 -5.1 -39.1

3D-CRT / other 

EBRT 

Non-self-referring 5.0 2.5 -2.5 -50.4

Self-referring 0.8 0.7 -0.1 -14.3

Switcher 4.0 1.3 -2.7 -68.7

Other treatments Non-self-referring a 5.7 6.3 0.6 10.8

Self-referring 1.8 2.5 0.7 38.3

Switcher 4.8 1.9 -2.8 -59.7

Source: GAO analysis of CMS data.

Appendix V: Change in Prostate Cancer 

Treatment Patterns over Time for Different 

Types of Providers
Appendix V: Change in Prostate Cancer 

Treatment Patterns over Time for Different 

Types of Providers

Page 41 GAO-13-525 Medicare Self-Referral of IMRT Services

Notes: Treatment categories for each type of provider do not sum to 100 percent because, with the 

exception of active surveillance and hormone therapy only, the categories are not mutually exclusive.

In 2007, switchers, self-referring providers, and non-self-referring providers referred 4,903, 1,776, and 

42,471 prostate cancer patients for treatment, respectively. In 2009, switchers, self-referring

providers, and non-self-referring providers referred 4,156, 1,244, and 34,107 prostate cancer patients 

for treatment, respectively. Because some treatments were relatively rare, some provider type, 

treatment group, and year categories, such as patients referred for 3D-CRT / other EBRT by selfreferring providers in 2009, have relatively few beneficiaries. However, the results of this analysis are 

consistent with the trends observed when referral patterns for self-referring and non-self-referring 

providers were studied for all beneficiaries diagnosed in 2007 and 2009.

a

“Other treatments” consists of cryoablation, stereotactic body radiotherapy / stereotactic 

radiosurgery, and proton therapy.
Appendix VI: Comments from the Department 

of Health and Human Services

Page 42 GAO-13-525 Medicare Self-Referral of IMRT Services

Appendix VI: Comments from the 

Department of Health and Human Services
Appendix VI: Comments from the Department 

of Health and Human Services

Page 43 GAO-13-525 Medicare Self-Referral of IMRT Services
Appendix VII: GAO Contact and Staff 

Acknowledgments

Page 44 GAO-13-525 Medicare Self-Referral of IMRT Services

James C. Cosgrove, (202) 512-7114 or cosgrovej@gao.gov

In addition to the contact named above, Thomas Walke, Assistant 

Director; Manuel Buentello; Krister Friday; Gregory Giusto; 

Brian O’Donnell; Daniel Ries; and Jennifer Whitworth made key 

contributions to this report.

Appendix VII: GAO Contact and Staff 

Acknowledgments 

GAO Contact

Staff 

Acknowledgments

(290972)
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