Association of local capacity for endoscopy with individual use of colorectal cancer screening and stage at diagnosis.

BACKGROUND: Limited capacity for endoscopy in areas in which African Americans and Hispanics live may be a reason for persistent disparities in colorectal cancer (CRC) screening and stage at diagnosis.
METHODS: The authors linked data from the National Health Interview Survey on the use of CRC screening and data from Surveillance, Epidemiology, and End Results-Medicare on CRC stage with measures of county capacity for colonoscopy and sigmoidoscopy (endoscopy) derived from Medicare claims.
RESULTS: Hispanics lived in counties with less capacity for endoscopy than African Americans or whites (for National Health Interview Survey, an average of 1224, 1569, and 1628 procedures per 100,000 individuals aged > or = 50 years, respectively). Individual use of CRC screening increased modestly as county capacity increased. For example, as the number of endoscopies per 100,000 residents increased by 750, the odds of being screened increased by 4%. Disparities in screening were mitigated or diminished by adjustment for area endoscopy capacity, racial/ethnic composition, and socioeconomic status. Similarly, among individuals with CRC, those who lived in counties with less endoscopy capacity were marginally less likely to be diagnosed at an early stage. Adjustment for area characteristics diminished disparities in stage for Hispanics compared with whites but not African Americans.
CONCLUSIONS: Increasing the use of CRC screening may require interventions to improve capacity for endoscopy in some areas. The characteristics of the area where an individual resides may in part mediate disparities in CRC screening use for both African Americans and Hispanics, and disparities in cancer stage for Hispanics.