supplement to the urologists-imrt study from the new england journal of medicine

7/27/2019 Supplement to the Urologists-IMRT study from the New England Journal of Medicine

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Supplementary Appendix

This appendix has been provided by the authors to give readers additional information about their work.

Supplement to: Mitchell JM. Urologists use of intensity-modulated radiation therapy for prostate cancer. N Engl

J Med 2013;369:1629-37. DOI: 10.1056/NEJMsa1201141


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Supplementary Materials for MS# 12-01141.R6 Urologists Use of Intensity Modulated Radiation

Therapy for Prostate Cancer

Author: Jean M. Mitchell, Ph.D., Professor of Public Policy, Georgetown University

Table of Contents

1) Sample Selection Criteria Submitted to the Center for Medicare and Medicaid Services2) SAS Program Used to Extract Sample of Men with Newly Diagnosed Prostate Cancer3) SAS Program to Construct Variables Used in IMRT Analysis4) Specification of the Empirical Model5) Table S1: Linear Probability and Logistic Regression Difference-in-Differences Estimates

Predicting Receipt of IMRT Treatments among Medicare Fee-for-Service Beneficiaries with

Newly Diagnosed, Non-metastatic Prostate Cancer

6) Analysis of Time-to-Treat by Self-referral Status7) Figure S1: Frequency of Use of IMRT among Men Age 65-79 with Newly Diagnosed Prostate

Cancer-- Private Practice Self-referring Urologists versus Private Practice Non Self-referring

Urologists

8) Figure S2: Frequency of Use of IMRT among Men Age 80 Plus with Newly Diagnosed ProstateCancer--Private Practice Self-referring Urologists versus Private Practice Non Self-referring

Urologists

9) Figure S3: Frequency of Use of IMRT among Men Age 65-79 with Newly Diagnosed ProstateCancer--Private Practice Self-referring Urologists versus National Comprehensive Cancer

Network Non Self-referring Urologists

10)Figure S4: Frequency of Use of IMRT among Men Age 80 Plus with Newly Diagnosed ProstateCancer--Private Practice Self-referring Urologists versus National Comprehensive Cancer

Network Non Self-referring Urologists


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Sample Selection Criteria Submitted to the Center for Medicare and Medicaid Services

The Center for Medicare and Medicaid Services algorithm to identify beneficiaries with prostate

cancer is available on the Chronic Conditions Warehouse website

(ww.ccwdata.org/web/guest/conditions-categories). Prostate cancer is identified by at least 1 inpatient

or two carrier or hospital outpatient claims with ICD-9 diagnosis codes 185 or 233.4.

My data request to CMS stipulated using the Chronic Conditions Warehouse algorithm to extract

Medicare beneficiaries with prostate cancer who were continuously enrolled in fee-for-service during

the time period 2005-2010. Only beneficiaries who resided in 26 designated states were selected. We

attempted to identify newly diagnosed prostate cancer cases in each year by a date variable that

identifies the first occurrence of prostate cancerthe variable CANCER_PROSTATE_EVER.

The data came from 17 states where the 37 self-referring practices identified by the Wall Street

Journal were located. We also requested data for some nearby states where there were no known self-

referring practices. These states include: Connecticut, Georgia, Massachusetts, Michigan, Minnesota,

North Dakota, Tennessee, Utah and Washington. In the process of working with the CMS vendor to

revise the parameters of the original data request to include additional states, Ohio was inadvertently


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SAS Program to Extract Sample of Men with Newly Diagnosed Prostate Cancer

We used the SAS program presented below to extract men with newly diagnosed prostate

cancer from the initial data extract obtained. Men with metastatic prostate cancer were excluded.

These cases were identified by ICD-9 codes reported as secondary diagnosis codes on the claims. These

codes are: 198.5 (secondary neoplasm of bone and bone marrow) and 196 (secondary and unspecified

malignant neoplasm of lymph nodes); ICD-9 code 196 has 8 sub codes which describe location.

PROGRAM CODE

%LET GROUP=;

%LET PRED=;

%LET POSTD=;

%LET GRPTAX=;

%LET GRPUPIN=;

%LET GRPNPI=;

%MACRO PYR(YR);

*** check all claims for IDs from group of interest ***;

DATA PRERADGFL_&YR (KEEP=BENE_ID GROUP GROUP_: PRE POST);


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RUN;

*** capture all claims for bene that had claim with group of interest - do per year ***;

PROC SORT NODUPKEY DATA=PRERADGFL_&YR;

BY BENE_ID GROUP;

RUN;

DATA PRERADGFL2_&YR;

MERGE PRERADGFL_&YR (IN=A)

INSASG.CMSRAD_&YR (IN=B);

BY BENE_ID;

IF A;

RUN;

%MEND PYR;

%PYR(05);


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PRERADGFL2_06

PRERADGFL2_07

PRERADGFL2_08

PRERADGFL2_09

PRERADGFL2_10;

IF GROUP="&GROUP";

RUN;

PROC SORT DATA=PRERAD&GROUP._ALLYR OUT=INSASRAD.PRERAD&GROUP._ALLYR;

BY BENE_ID CLM_THRU_DT;

RUN;

%MEND GRP;


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SAS Program to Construct Variables Used in IMRT Analysis

DATA EPISODEBENEPRE_&GROUP (KEEP=BENE_ID BIOPWCANCDATE BIOPSYDATERENAME=(BIOPWCANCDATE=NEWYEAR));

SET INSASRAD.PRERAD&GROUP._ALLYR;


RETAIN BIOPWCANCDATE BIOPSYDATE BIOPWCANCF;

IF FIRST.BENE_ID THEN DO;

BIOPWCANCF=0;

BIOPWCANCDATE=.; BIOPSYDATE=.;

END;

*** flag claims with group ***;

IF LEFT(TRIM(TAX_NUM)) IN (&GRPTAX)

OR LEFT(TRIM(PRF_PHYSN_UPIN)) IN (&GRPUPIN)

OR LEFT(TRIM(PRF_PHYSN_NPI)) IN (&GRPNPI) THEN GROUPCLAIM=1;

*** flag claims for prostate cancer diag (including in situ) ***;

ARRAY DIAG(*) $ ICD9_DGNS_CD1-ICD9_DGNS_CD8;

DO I 1 TO DIM(DIAG)


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IF LAST.BENE_ID THEN OUTPUT;

RUN;

DATA EPISODEBENEPRE2_&GROUP (RENAME=(PRE=PREDATE POST=POSTDATE));

MERGE EPISODEBENEPRE_&GROUP (IN=A)

INSASRAD.PRERAD&GROUP._ALLYR (IN=B);

BY BENE_ID;

*** 6 month episode ***;

IF A AND B AND ((NEWYEAR-41) LE CLM_THRU_DT LE (NEWYEAR+183));

RUN;

DATA EPISODEBENE_&GROUP (DROP=I J K)

EPISODEBENE3_&GROUP (DROP=I J K)

EPISODEALL_&GROUP (DROP=I J K);

SET EPISODEBENEPRE2_&GROUP;


RETAIN &GROUP.COUNT FIRST&GROUP.DATE LAST&GROUP.DATE &GROUP.OFFVISF


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IF FIRST.BENE_ID THEN DO;

ARRAY INITZ(*) TREATAGE &GROUP.COUNT &GROUP.OFFVISF PROSTATEF BIOPWCANCF&GROUP.CANCERF CANCERONBIOPF IMRTPF IMRTDF &GROUP.IMRTPF &GROUP.IMRTDF

PROSTATECTOMYF &GROUP.PROSTATECTOMYF BRACHYF &GROUP.BRACHYF

HORMONEF &GROUP.HORMONEF CRYOF &GROUP.CRYOF RADIOF &GROUP.RADIOF TRANSF

&GROUP.TRANSF IMRTPC IMRTDC &GROUP.IMRTPC &GROUP.IMRTDC &GROUP.DAYS CANCERPROC

NOT_&GROUP.IMRTDF NOT_&GROUP.IMRTDC;

DO J=1 TO DIM(INITZ);

INITZ(J)=0;

END;

ARRAY INITM(*) FIRST&GROUP.DATE LAST&GROUP.DATE CDATE FIRST&GROUP.CDATE

BIOPWCANCDATE BIOPSYDATE CANCERONBIOPDATE &GROUP.BIOPSYDATE FIRSTIMRTPDATE

FIRSTIMRTDDATE FIRST&GROUP.IMRTDATE TREATDATE

&GROUP.DATE;

DO K=1 TO DIM(INITM);

INITM(K)=.;

END;

END;

*** fl l i if id i i h f i l fi d f l i i h f l i i h


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*** flag claims for prostate cancer diag (including in situ) ***;

ARRAY DIAG(*) $ ICD9_DGNS_CD1-ICD9_DGNS_CD8;

DO I=1 TO DIM(DIAG);

IF DIAG(I) IN ("185","2334") THEN DO;

*** flag claim as prostate cancer, retain flag for bene with prostate cancer, note date of first diagnosis

***;

PROSTATE=1; PROSTATEF=1; IF CDATE=. THEN DO; CDATE=CLM_THRU_DT; END;

*** flag bene for having a cancer diagnosis on a claim by a group dr ***;

IF &GROUP.CLAIM=1 THEN DO; &GROUP.CANCERF=1; IF FIRST&GROUP.CDATE=. THEN

FIRST&GROUP.CDATE=CLM_THRU_DT; END;

IF (CLM_THRU_DT-30) LE BIOPSYDATE THEN DO; BIOPWCANCF=1; IF BIOPWCANCDATE=.

THEN BIOPWCANCDATE=CLM_THRU_DT; END;

IF CLM_THRU_DT=BIOPWCANCDATE THEN CANCERPROC=1;

END;

END;

*** flag claim and bene for having office visit with dr in group ***;

IF SUBSTR(HCPCS_CD,1,3)='992' AND &GROUP.CLAIM=1 THEN DO;


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IF &GROUP.CLAIM=1 THEN &GROUP.BIOPSYDATE=CLM_THRU_DT;

END;

*** flag treatments - from group and from anyone ***;

IF HCPCS_CD="77301" THEN DO;

IMRTP=1; IMRTPF=1; IMRTPC+SUM(REV_CNTR_UNIT_CNT,LINE_SRVC_CNT);

IF FIRSTIMRTPDATE=. THEN FIRSTIMRTPDATE=CLM_THRU_DT;

IF &GROUP.CLAIM=1 THEN DO; IF FIRST&GROUP.IMRTDATE=. THEN

FIRST&GROUP.IMRTDATE=CLM_THRU_DT; &GROUP.IMRTP=1; &GROUP.IMRTPF=1;

&GROUP.IMRTPC+SUM(REV_CNTR_UNIT_CNT,LINE_SRVC_CNT); END;

END;

IF HCPCS_CD="77418" THEN DO;

IMRTD=1; IMRTDF=1; IMRTDC+SUM(REV_CNTR_UNIT_CNT,LINE_SRVC_CNT);

IF FIRSTIMRTDDATE=. THEN FIRSTIMRTDDATE=CLM_THRU_DT;

IF &GROUP.CLAIM=1 THEN DO; IF FIRST&GROUP.IMRTDATE=. THEN

FIRST&GROUP.IMRTDATE=CLM_THRU_DT; &GROUP.IMRTD=1; &GROUP.IMRTDF=1;

&GROUP.IMRTDC+SUM(REV_CNTR_UNIT_CNT,LINE_SRVC_CNT); END;

IF &GROUP.CLAIM NE 1 THEN DO; NOT_&GROUP.IMRTD=1; NOT_&GROUP.IMRTDF=1;

NOT_&GROUP.IMRTDC+SUM(REV_CNTR_UNIT_CNT,LINE_SRVC_CNT); END;


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IF HCPCS_CD IN ("77435","G0339","G0340") THEN DO; RADIO=1; RADIOF=1; IF &GROUP.CLAIM=1

THEN &GROUP.RADIOF=1; END;

IF HCPCS_CD IN ("53850","53852","53853", "52601") THEN DO; TRANS=1; TRANSF=1; IF

&GROUP.CLAIM=1 THEN &GROUP.TRANSF=1; END;

*** note first date of treatment ***;

IF TREATDATE=. AND (PROSTATECTOMY=1 OR BRACHY=1 OR IMRTD=1) THEN DO;

TREATDATE=CLM_THRU_DT;

TREATAGE=BENE_AGE_AT_END_REF_YR;

END;

LABEL PROSTATE="claim has malignant neoplasm/in situ of prostate"

PROSTATEF="bene has malignant neoplasm/in situ of prostate"

SECONDF="bene has a secondary treatment - prostatectomy, brachy"

TERTIARYF="bene has a tertiary treatment - cryo, radio, trans"

IMRTDF="bene had IMRT delivery (77418)"

IMRTPF="bene had IMRT planning (77301)"

BIOPWCANCF="bene has a biopsy and a cancer diagnosis w/in 30 days"

CANCERONBIOPF="bene has a cancer diagnosis on a biopsy claim"


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IF LAST&GROUP.DATEMDY(6,30,2010) THEN NEWDIAG=0;

IF &GROUP.PROSTATECTOMYF=1 OR &GROUP.BRACHYF=1 THEN &GROUP.SECONDF=1;

IF &GROUP.CRYOF=1 OR &GROUP.RADIOF=1 OR &GROUP.TRANSF=1 THEN &GROUP.TERTIARYF=1;

IF &GROUP.IMRTDF=1 AND SECONDF NE 1 THEN &GROUP.IMRTDONLY=1;


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*** 6 month requirement for pre period ***;

IF PRE=1 AND NEWDIAG=1 AND BIOPWCANCDATE>(PREDATE-183) THEN NEWDIAG=0;

IF FIRSTIMRTPDATE NE . AND FIRSTIMRTDDATE NE . THEN IMRTP2D=FIRSTIMRTDDATE-

FIRSTIMRTPDATE;

*** do not include benes with


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Specification of the Empirical Model

The dependent variable receipt of IMRT treatments equals 1 if: 1) the beneficiary was seen by a

non self-referring urologist in either the preownership or ownership periods and he received IMRT

treatments; or 2) the beneficiary was seen by a self-referring urologist in the preownership period and

he received IMRT treatments; or 3) the beneficiary was seen by a self-referring urologist in the

ownership period and he received IMRT treatments performed and billed by the self-referring urology

group. For all other observations the dependent variable equals zero. This includes beneficiaries seen by

a self-referring urologist during the ownership period that underwent IMRT treatments performed and

billed by a non self-referring provider (about 6% of the primary sample). Although these beneficiaries

received IMRT treatments, assigning a value of 1 to these cases would bias upward the coefficient on

the self-referral variable.

The unadjusted analyses only control for: 1) whether the case was treated in the preownership

or ownership period, 2) self-referral status and 3) whether the patient was treated by a self-referring

urologist after acquiring ownership. The unadjusted analyses do not control for any other confounding

factors. Each matched pair has the same preownership and ownership period.


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rapidly adopted during the time period of study, despite uncertainty regarding its relative effectiveness.2

Indicator variables identifying the 70 urology groups that comprise the primary sample were included to

control for variations in physician practices patterns that are likely to exist but are unrelated to self-

referral status.

References

1. Elixhauser, A, Steiner, C, Harris, DR and Coffey RM. Comorbidity Measures for Use with

Administrative Data. Medical Care. 1998; 36(1): 8-27.

2 . Jacobs BL, Zhong Y, Skolarus, TA, Hollenbeck, BK. Growth of High-Cost Intensity Modulated

Radiation Therapy for Prostate Cancer Raises Concerns about Overuse.

Health Affairs, 2012; 31(4): 750-759.


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Table S1. Linear Probability and Logistic Regression Difference-in-Differences Estimates

Predicting Receipt of IMRT Treatments among Fee-for-Service Medicare Beneficiaries with

Newly Diagnosed Non-metastatic Prostate Cancera

Private Practice Self-referring Private Practice Self-referring

Urologists vs. Private Practice Urologists vs. NCCN

Non Self-referring Urologistsc

Non Self-referring Urologistsd

Beneficiary Treated by Self-

referring Urologist during

Ownership Period (n= 38,765)

Beneficiary Treated by Self-

referring Urologist during

Ownership Period (n=6,773)Marginal EffectLinearProbability Model

16.4% points

(p


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Analysis of Time-to-Treat by Self-referral Status

Self-referring urologists contend that the vertically integrated urology-radiation oncology

practice reduces time-to-treat, that is, time from date of cancer diagnosis to initiation of definitive

treatment. If so then one would expect to find that men treated by self-referring urologists will

experience a reduction in time-to-treat compared to men who obtained care from non self-referring

urologists. Results reported below show this is not the case. After controlling for type of definitive

treatment received (brachytherapy, IMRT only or prostatectomy) and other confounding factors, time-

to-treat does not vary by self-referral status.

Table S2. Length of Time from Date of Prostate Cancer Diagnosis to Date of Receipt of Definitive

Treatment (Brachytherapy, Prostatectomy, IMRT)

Sample Difference-in-Differences

(Self-referral) Effect

(Unadjusted)

Difference-in-Differences

(Self-referral) Effect

(Adjusted)b

Private Practice Self-referring Urologists

Versus Private Practice Non Self-referring

Urologists

-3.0

(p


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In addition, we estimated a regression where the dependent variable was length of time in days from

date of diagnosis until receipt of definitive treatment controlling for treatment by a self-referring

urologist in the ownership period, urology group fixed effects, type of definitive treatment

(brachytherapy, IMRT only or prostatectomy), age, year of cancer diagnosis and comorbid illnesses. The

coefficient on the self-referral variable was 1.29 (p = 0.12) and was not statistically significant. Thus, the

regression-adjusted results show there was no difference in length of time from date of cancer diagnosis

to receipt of definitive treatment associated with self-referral.

Private Practice Self-referring Urologists versus National Comprehensive Cancer Network

Non Self-referring Urologists

Difference-in-difference results from time-to-treat comparisons of men treated by self-

referring urologists and their non self-referring counterparts employed by cancer centers are reported in

row 2 of Table S2. The unadjusted difference-in-differences estimator or self-referral effect was a

decline in time-to-treat of 6.4 days (p


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supplement to the urologists-imrt study from the new england journal of medicine

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