Regional variation in colorectal cancer testing and geographic availability of care in a publicly insured population.

Despite its demonstrated effectiveness, colorectal cancer (CRC) testing is suboptimal, particularly in vulnerable populations such as those who are publicly insured. Prior studies provide an incomplete picture of the importance of the intersection of multilevel factors affecting CRC testing across heterogeneous geographic regions where vulnerable populations live. We examined CRC testing across regions of North Carolina by using population-based Medicare and Medicaid claims data from disabled individuals who turned 50 years of age during 2003-2008. We estimated multilevel models to examine predictors of CRC testing, including distance to the nearest endoscopy facility, county-level endoscopy procedural rates, and demographic and community contextual factors. Less than 50% of eligible individuals had evidence of CRC testing; men, African-Americans, Medicaid beneficiaries, and those living furthest away from endoscopy facilities had significantly lower odds of CRC testing, with significant regional variation. These results can help prioritize intervention strategies to improve CRC testing among publicly insured, disabled populations.