Abstract
Background and Aims: Several studies have found variations in cancer health outcomes among persons in different socioeconomic (SES) groups, but the presence and extent of such disparities in insured populations is unclear. The objective of this study was to determine whether, among persons enrolled in HMOs, there are differences in the use of services for early detection of cancer according to neighborhood SES.
Methods: This was a retrospective cohort study of men and women aged 50+ years, enrolled for at least 1 calendar year beginning in 2000 at one of 3 health plans participating in the Cancer Research Network. Follow-up was to the date of disenrollment from the health plan, or December 31, 2007, whichever was earlier. Using administrative data, we obtained dates of examinations and tests related to screening for colorectal cancer (CRC) for men and women and mammography among women. CRC tests were defined as time to the first colonoscopy or sigmoidoscopy (endoscopy) during the follow-up period; and also time to an endoscopy that was not preceded by gastrointestinal conditions in the 6 months prior to the test. SES neighborhood measure was computed using 12 US Census (2000) measures of racial and SES composition and context at the tract level.
Results: A total of 123,222 members, 54% women and average age 64 years, were followed for an average of 5.5 (SD=2.8) years. During 673,938 person-years of follow-up, about 41% had at least 1 endoscopy and 32% had an endoscopy not associated with prior GI-related diagnoses. Among women, 77% had at least 1 mammogram during the study period; 7% had mammograms during each of the first 5 years of follow-up. In Cox regression models, compared to lowest quartile of SES, persons residing in the highest quartile had a hazard ratio (HR) of 0.76: (95% confidence interval (CI): 0.75–0.78) for receipt of any endoscopy; 0.72: (CI: 0.70–0.74) for ‘screening’ endoscopy; and 0.86: (CI: 0.84–0.88) for mammography.
Conclusion: Even among patients receiving care in HMOs, those in socioeconomically deprived neighborhoods are less likely to undergo cancer early detection services. Interventions targeting enrollees residing in lower SES neighborhoods may help reduce cancer health disparities.
- Received May 27, 2010.
- Accepted May 27, 2010.
