Address correspondence to Siran M. Koroukian, Ph.D., Assistant Professor, Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4945. Fang Xu, M.S., Data Coordinator, is with the Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, OH. Avi Dor, Ph.D., Professor in Health Care Economics, is with the Department of Economics, Director of Research, Health Systems Management Center, Weatherhead School of Management, Case Western Reserve University, Cleveland OH. Gregory S. Cooper, M.D., Professor, is with the Division of Gastroenterology, University Hospitals of Cleveland, Cleveland, OH.
Colorectal Cancer Screening in the Elderly Population: Disparities by Dual Medicare–Medicaid Enrollment Status
Article first published online: 20 JUN 2006
Health Services Research
Volume 41, Issue 6, pages 2136–2154, December 2006
How to Cite
Koroukian, S. M., Xu, F., Dor, A. and Cooper, G. S. (2006), Colorectal Cancer Screening in the Elderly Population: Disparities by Dual Medicare–Medicaid Enrollment Status. Health Services Research, 41: 2136–2154. doi: 10.1111/j.1475-6773.2006.00585.x
- Issue published online: 20 JUN 2006
- Article first published online: 20 JUN 2006
- Dual eligibility;
- managed care;
- colorectal cancer screening;
- administrative claims data
Objectives. To assess the disparities in colorectal cancer (CRC) screening between elderly dual Medicare–Medicaid enrollees (or duals), the most vulnerable subgroup of the Medicare population, and nonduals.
Data Sources/Study Setting. The 1999 Medicare Denominator File, the Medicare Outpatient Standard Analytic Files, and Physician Supplier Part B files. In addition, the 1998 Area Resource File was used as a source for county-level attributes.
Data Collection/Extraction Methods. CRC screening procedures for 1999—fecal occult blood test (FOBT), flexible sigmoidoscopy (FLEX), colonoscopy with FOBT and/or FLEX (COL-WFF), and colonoscopy only (COL-ONLY)—were extracted from claim records, using diagnostic and procedure codes. Duals (n=2.5 million) and nonduals (n=20.2 million) receiving their care through the fee-for-service system were identified from the Denominator file. Hierarchical logistic regression analysis was conducted to adjust for individual- and county-level characteristics.
Principal Findings. Compared with nonduals, duals were disproportionately represented by female, older-old, and minority individuals (respectively 74.4 versus 58.5 percent; 19.3 versus 10.8 percent; 35.7 versus 8.0 percent), and CRC screening was significantly lower in duals than in nonduals (5.1 versus 12.2 percent for FOBT adjusted odds ratio [AOR]: 0.48, 95 percent confidence interval [CI]: 0.45–0.51); 0.7 versus 1.9 percent for FLEX, (AOR: 0.55, 95 percent CI: 0.49–0.61); 0.4 versus 0.8 percent for COL-WFF (AOR: 0.60, 95 percent CI: 0.54–0.67); and 1.8 versus 2.5 percent for COL-ONLY (AOR: 0.85, 95 percent CI: 0.80–0.89); p<.001 for all comparisons.
Conclusions. Duals are significantly less likely than nonduals to undergo CRC screening, even after adjusting for individual- and county-level covariates. Future studies should evaluate the contribution of comorbidity and low socioeconomic status to these disparities.