Abstract
BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer death in US adults but can be reduced by screening. The roles of individual and contextual factors, and especially physician supply, in attaining universal CRC screening remains uncertain.
METHODS: We used data from adults 50-75 years old participating in the 2018 New York (NY) Behavioural Risk Factor Surveillance System linked to county-level covariates, including primary care physician (PCP) density and gastroenterologist (GI) density. Data were analysed in 2023-2024. Our analyses included (1) ecological and geospatial analyses of county-level CRC screening prevalence and (2) individual-level Poisson regression models of receipt of screening, adjusted for socioeconomic and county-level contextual variables.
RESULTS: Mean prevalence of up-to-date CRC screening was 71% (95% CI 70% to 73%) across NY's 62 counties. County-level CRC screening demonstrated significant spatial patterning (Global Moran's I=0.14, p=0.04), consistent with the existence of county-level contextual factors. In both county-level and individual-level analyses, lack of health insurance was associated with lower likelihood of up-to-date screening (ß=-1.09 (95% CI -2.00 to -0.19); adjusted prevalence ratio 0.68 (95% CI 0.60 to 0.77)), even accounting for age, race/ethnicity and education. In contrast, county-level densities of both PCPs and GIs were completely unassociated with screening at either the county or individual level. As expected, other determinants at the individual level included education status and age.
CONCLUSION: In this state-wide representative analysis, physician density was completely unassociated with CRC screening, although health insurance status remains strongly related. In similar screening environments, broadened insurance coverage for CRC screening is likely to improve screening far more effectively than increased physician supply.