Colorectal Cancer Screening in the US: The Impact of Oversurveillance, Physician Supply and Coverage Mandates

Abstract

Screening for precursor adenomatous polyps has been proven to be effective in reducing colorectal cancer mortality risk. Although most screening guidelines do not recommend any one of the several screening tests for CRC over the others, colonoscopy increasingly is being adopted as the primary test for screening. In addition, colonoscopy is recommended for post-polypectomy and post-colectomy surveillance of colorectal cancer. Despite the considerable evidence supporting the effectiveness of screening for CRC, its uptake has lagged considerably behind that of breast cancer screening. Over the past twenty years, the Department of Health and Human Services (DHHS), the Centers for Disease Control and Prevention (CDC) and many national, state and local organizations have embarked on several programs and campaigns in a bid to raise awareness about colorectal cancer and increase screening uptake. At the same time, there is a growing concern that the current physician supply is inadequate to support a broader colonoscopy-based screening and surveillance. This research examines these concerns from three fronts. First, we use a population-based state-transition Markov model of the natural history of colorectal cancer, applied to census data and prevailing screening guidelines, to forecast the demand for colonoscopy and examine the impact of premature post-polypectomy CRC surveillance on the annual volume of colonoscopies. Second, we combine the Behavioral Risk Factor Surveillance System (BRFSS) survey with physician resource data to examine the conditional effect of county-level physician supply on screening participation. Third, we use longitudinal BRFSS survey data to estimate the effect of the policy of state-mandated colorectal cancer screening benefit by health insurers on the probability of an insured individual undergoing screening.