Racial differences in indications for colorectal procedures in medicare beneficiaries

calcium, aspirin) or placebo. Follow up colonoscopy to document incident adenomas was performed at one and four years after qualification in CPPS and after three years in APPS. Subjects were surveyed at baseline and every four months thereafter regarding medication usage. For this analysis, subjects were considered exposed if they reported any use of H 1RA's or H2RA's. Our main outcome was the development of any adenoma during the trials. We also evaluated the association of exposure with advanced and multiple adenomas. Risk ratios obtained by log linear models were adjusted for age, sex, clinical center, treatment category, lifetime number of adenomas and duration of the observation period. Results: 830 subjects completed the CPPS and 1084 completed the APPS. Use of H1RA's was less frequent in CPP5 (14.1%) than in the later APPS (43.6%). Use of H2RA's was more frequent in CPPS (206%) than in APPS (9.9%). Exposure to H1RA's had no protective effect on incident adenorna development in either CPPS (RR = 1.19 95% CI 0.63, 2.27) or APPS (RR = 1.08 95% CI = 0.93, 1.24). Analysis examining the effect of H1RA exposure on advanced and multiple adenomas also showed no protective benefit in either study. Exposure to H2RA's had no effect on incident adenoma development in either CPPS (RR = 0.93 95% Cl 073, 119) or APPS (RR = 1.00 95% CI 079, 1.25). In CPPS, subjects exposed to H2RA'swere somewhat less likely to develop multiple incident adenomas (RR = 0.65, 95% EI 40, 1.07).However~ this finding was not duplicated m APPS (RR = 1.10, 95% C1.74, 162). There was no trend for protection from advanced adenomas. Conclusion: Exposure to H IRA's and H2RA's did not significantly influence the development of incident adenomas. While this study has limitations (e.g. crude measure of exposure), it suggests that any protective effect ycould be small. Based on our results, randomized trials of these agents for the purpose of polyp prevention may not be warranted

patient satisfaction within the VA by increasing access to primary care at the expense of acute services. This study supports previous work that access to care is an important predictor of CRC outcomes.

629 Racial Differences in Indications for Colorecta] Procedures in Medicare Beneficiaries Gregory S. Cooper, Siran M. Koroukian Background: Colorectal cancer mortality rates have generally been higher in African American (AA) than white patients, which may he partly due to racial disparity in receipt of Screening procedures. However, the actual use of procedures in racial groups has not been well studied at a population-based level. Methods: All Medicare claims for fecal occult blood testing (FOBT), flexible sigmoidoscopy (FS), colonoscopy (CY) and barium enema (BE) from 19971999 were identifed from hospital outpatient & physician-supplier files. Patients were excluded if they were < 65 years. The diagnosis codes associated with the procedure were used to categorize the indicatmn as diagnostic (DX) (code indicating signs or symptoms), screening (SCR) (no code indicating signs or symptoms) or for CY, surveillance (SUR) (prior history of polyp, cancer, inflammatory bowel disease). Age-adjusted rates were expressed as per 100,000 fee-for-service (FFS) mouths to account for partial year eligibility and receipt of services through the FFS system. The cohort included more than 33 million individuals per year. Results: Overall rates for FOBT, FS and CY were higher in white patients than African Americans, and the overall rate of BE was higher in African American patients. Data stratified by procedural indication are shown in the Table. Almost all of the racial difference in the overall use of procedures was attributed to SCR or 8UR Considerably smaller racial differences were observed for DX indications, and rates of CY for DX were actually higher in African Americans. In addition, women were more likely than men to undergo endoscopic procedures for DX but less likely for SCR Conclusions: The racial differences in procedural indication, with a potential delay in evaluation until signs or symptoms develop, may account in part for the higher colorectal cancer mortality in African Americans.

615 Predictors of Large and Small Adenomas in a Screening Population Joseph C Anderson, ZVI A. Alpem, Bernard Lane, Patricia Ells, Peter F. Ells, Douglas L. Brand Background: Potter has proposed the following mechanism (Journal NCI vol.91 page 916, 1999"1:Small adenomas may develop in response to germline mutations (e.g.APC) and blond borne carcinogens. As the adenomas grow larger other genetic (e.g. K-ras oncogene) and environmental stimuli in the fecal stream may promote their growth. Our goal was to examine the association between genetic and environmental risk factors and small versus large adenomas. Methods:Data collected from 1900 asymptomatic screening colonoscopy patients included age, gender, family history of neoplasia, height, weight, fruit/vegetable intake, smoking habits, alcohol use, education, NSAID use, ethnicity and exercise.Results: Therewere 211 (11.1% ),small adenomas and 70(3.7%) large adenomas. Multivariate analyses are shown in the Table. Conclusions: Environmental factors such as BMI, alcohol and current smoking appear to be associated with large adenomas and thus may play a role with oncogenes (K-ras). Genetic factors such as gender and family history are associated with small adenomas. Our data confirm the development hypothesis of large adenomas.

Procedure Rate per 100,000 FF8 Months Procedure FOBT.DX FOBT.$CR FS-DX FS-SCR CY.DX CY-SUR CY.SCR BE.DX BE-$CR p<0.0001for all comparisons

Riskfactorsasso~ated with large end small sdenomae (Odds Ratio)

A0e:,,57 Familyhistoryof Cancer Gender

Smo~dng(>10packyears) BMI

AJcoho~(>6clrlnlu~vonk}

Snudl p OR=2.2(95%Ot;l.7- 0.001 2.7) OR=1.7(95%CI;1..4- 0.001 2.0)

OR:0.6(95%Cl;.4-.8)0.001 N8 NS NS

as

NS

NS

Larte NS

p NS

NS

NS

AAM 327 524 72 108 260 47 248 124 63

WF 452 1125 100 146 224 69 260 116 69

AAF 399 663 83 103 269 "43 235 142 76

630 Promoting Colorectal Cancer (CRC) Screening in First-Degree Relatives (FDRs) of Patients with CRC Stephen P. Laird, Christine Vanoin, Alfred C. Marcus, Dennis J. Ahnen

N8 NS OR=2,8(95%CJ;1.7. 0.001

CRC screening, starting by age 40, is recommended for FDRs of patients with CRC. PurposeTo determine if a telephone-based educational and counseling intervention can improve CRC screening rates in FDRs of CRC patients. Methods- 1265 consenting FDRs of CRC patients, aged 40-75, were randomized to receive a telephone interview (control group) or the interview plus a brief (12 vain), tailored educational and barriers counseling module designed to promote CRC screening (intervention group). Questions about colon cancer screening, potential mediating variables for CRC screening, and barriers to CRC screening were asked at baseline, 3 and 12 months. Odds ratios (OR) of the impact of the intervention on CRC screening after adjustment for demographics were calculated. Results- The baseline screening rate was 45% in both study groups The 12-month screening rates were significantly higher in the intervention than in the control group (70% vs 58%; OR 1.98; p<0.0001) Despite lower baseline screening rates in the 40-49 year old group than in the older groups (31% vs 51%-74%, p =0.001), the intervention was effective in increasing screening in this youngest subgroup (OR 1.74, p=0.014). Children of CRC patients had lower baseline screening rates than the siblings or parents (35% vs 56% and 63%, p<0.001 after adjustment for age) but the intervention was not effective in increasing CRC screening in th~s subgroup (OR 1.48, p=0.068). The intervention was somewhat more effective in men (OR 2.51, p=0.0005) than in women (OR 158, p=0.018)). The effect of the intervention improved endoscopic (OR 1 83, p<0.0001) but not FOBT screening rates (p = 0.25). The intervention favorably affected several mediating variables including knowledge of CRC screening recommendations (p = 0.03), efficacy of CRC screening (p = 0.0009), perceived CRC risk (p=0.004) and the barrier "unnecessary" (i.e no symptoms/other behaviors preclude need for CRC screening)(p = 0.0007). Conclusions- A brief educational and barriers counseling intervention increased knowledge about CRC screening recommendations, increased perceived efficacy of CRC screening tests, increased the FDRs understanding of their increased risk, decreased self-reported barriers to CRC screening and significantly improved endoscopic CRC screening rates in FDRs of CRC patients. Additional efforts to increase the impact of such interventions on CRC screening should be directed to women, to 40-49 year old FDRs and particularly to the adult children of patients with CRC.

4.5)

OR=1.44{95%CI;1.4- 0.01 1,50)

ORs1.4(95%Ctl,3.1,5)

WM 393 967 95 192 210 101 327 95 60

0.01

616 Colorectal Cancer: Risk Factors for Advanced Disease Deborah A Fisher, Christopher Martin, Joseph Galanko, Robert S. Sandier, Dawn Provenzale PURPOSE: Colorectal cancer (CRC) is curable if diagnosed in an early stage but has a fiveyear survival of only 14%-67% at more advanced stages. The goal of this study was to identifyprognostic fact6rs of late stage CRC, particularly those that are modifiable, including smoking, access to care and health seeking behavior. METHODS: The Colorectal Cancer RiskFactors for Advanced Disease study was conducted at 15 VA (Veterans Affairs) medical centersand included consecutive patients between the ages of 40 and 85 with a first diagnosis of histologically proven colon or rectal cancer between July 1, 1997 and January 1, 2001. Data were obtained by phone interview. A total of 683 patients were asked about income, heallh insurance, sources of health care, health status, history of cancer screening, physical acn*51y,tobacco use, family history and occupation. The primary outcome was stage at presentation: early (Dukes stage A or B) and late (Dukes stage C or metastatic). We used ~hechi square test for nominal variables and chi square test for trend for ordinal variables i0 examine the relationship between potential risk factors for early versus advanced stage disease Predictors with a p value <0.1 in univariate analysis were considered in the logistic regressionmodel. RESULTS: Five hundred fifty-two (552) respondents had stage data available and were included in this analysis. Approximately 43% of the sample presented with late stage CRC. In univariate analysis, lacking a usua[ source of health (doctor's office or clinic), lack of participation in any CRC Screening test in the last 10 years and increasing NSAIDuse over the previous five years (none, occasional, regular) was associated with late slage CRC In the logistic regression model, only lacking a usual source of healthcare was associated with late stage CRC with an odds ratio (95% confidence intervals) of 2.8 (1.647) Over 15% of the study sample lacked a usual source of care. For 77% of the patients v~ntha usual source of care, the care was received at a VA CONCLUSIONS: A considerable propomon, 43%, of veterans presented with late stage CRC The only independent predictor of late stage disease was lacking a usual source of healthcare This is a potentially modifiable osk factor, as previous research has demonstrated improvement in heaithcare quality and

A-79

AGA

Abstracts