Objective: To investigate racial differences in posttreatment bowel surveillance after colorectal cancer surgery in a large population of Medicare patients.
Data sources: We used a large population-based dataset: Surveillance, Epidemiology, and End Results (SEER) linked to Medicare data.
Study design: This is a retrospective cohort study. We analyzed data from 44,768 non-Hispanic white, 2,921 black, and 4,416 patients from other racial/ethnic groups, aged 65 and older at diagnosis, who had a diagnosis of local or regional colorectal cancer between 1986 and 1996, and were followed through December 31, 1998. Cox Proportional Hazards models were used to investigate the relation of race and receipt of posttreatment bowel surveillance.
Data collection: Sociodemographic, hospital, and clinical characteristics were collected at the time of diagnosis for all members of the cohort. Surgery and bowel surveillance with colonoscopy, sigmoidoscopy, and barium enema were obtained from Medicare claims using ICD-9-CM and CPT-4 codes.
Principal findings: The chance of surveillance within 18 months of surgery was 57 percent, 48 percent, and 45 percent for non-Hispanic whites, blacks, and others, respectively. After adjusting for sociodemographic, hospital, and clinical characteristics, blacks were 25 percent less likely than whites to receive surveillance if diagnosed between 1991 and 1996 (RR = 0.75, 95 percent CI = 0.70-0.81).
Conclusions: Elderly blacks were less likely than non-Hispanic whites to receive posttreatment bowel surveillance and this result was not explained by measured racial differences in sociodemographic, hospital, and clinical characteristics. More research is needed to explore the influences of patient- and provider-level factors on racial differences in posttreatment bowel surveillance.