Race, Poverty, and Mental Health Drive Colorectal Cancer Screening Disparities in the Veterans Health Administration

INTRODUCTION: Colorectal cancer (CRC) is a common but largely preventable malignancy. Screening is recommended for all adults aged 50-75 years; however, screening rates are low nationally and vary by patient factors and across health care systems. It is currently unknown whether there are inequities in CRC screening rates by patient sociodemographic and/or clinical factors in the Veterans Health Administration (VA) where the majority of patients are CRC screening-eligible age and CRC is the third most commonly diagnosed cancer. METHODS: We performed a retrospective cohort study using VA national clinical performance and quality data to determine the overall CRC screening rate, rates by patient sociodemographic and clinical factors, and predictors of screening adjusting for patient and system factors. We also determined whether disparities in screening exist in VA. RESULTS: The overall CRC screening rate in VA was 81.5%. Screening rates were lowest among American Indians/Alaska Natives 75.3%; adjusted odds ratio (aOR)=0.77, 95% confidence interval (CI)=0.65-0.90, those with serious mental illness (75.8%; aOR=0.65, 95% CI=0.61-0.69), those with substance abuse (76.9%; aOR=0.76, 95% CI=0.72-0.80), and those in the lowest socioeconomic status quintile (79.5%; aOR=1.10-1.31 for quintiles 2-5 vs. lowest quintile 1). Increasing age, Hispanic ethnicity, black race, Asian race, and high comorbidity were significant predictors of screening uptake. CONCLUSIONS: Many racial/ethnic disparities in CRC screening documented in non-VA settings do not exist in VA. Nonetheless, overall high VA CRC screening rates have not reached American Indians/Alaska Natives, low socioeconomic status groups, and those with mental illness and substance abuse. These groups might benefit from additional targeted efforts to increase screening uptake.