Colorectal Cancer Screening Among Individuals With a Substance Use Disorder: A Retrospective Cohort Study.

Introduction: There is limited evidence on colorectal cancer screening among individuals with a substance use disorder. This study aims to investigate the association between personal history of a substance use disorder and colorectal cancer colonoscopy screening completion rates. Methods: This retrospective cohort study analyzed 176,300 patients, of whom 171,973 had no substance use disorder and 4,327 had a substance use disorder diagnosis from electronic health record data (January 1, 2008-December 31, 2022) in a Midwestern healthcare system. Baseline was January 1, 2013, and a 10-year follow-up period ran through December 31, 2022. The outcome was receipt of colonoscopy in the 10-year follow-up period. Patients were aged 50-65 years at baseline, meaning that they were eligible for a colonoscopy through the entirety of the 10-year follow-up period. Covariates included demographics (age, race, and neighborhood SES), health services utilization, psychiatric and physical comorbidities, and prior colonoscopy or fecal occult blood testing. Entropy balancing was used to control for confounding in weighted log-binomial models calculating RR and 95% CIs. Results: Patients were on average aged 57.1 (±4.5) years, 58.2% were female, 81.0% were White, and 16.9% were of Black race. The most prevalent comorbidities were obesity (29.6%) and hypertension (29.4%), followed by smoking/nicotine dependence (21.0%). The most prevalent psychiatric comorbidity was depression (6.4%), followed by anxiety disorder (4.5%). During the 10-year follow-up period, 40.3% of eligible patients completed a colorectal cancer colonoscopy screening test, and individuals with a substance use disorder diagnosis were significantly less likely to receive a colorectal cancer colonoscopy screening test both prior to and after controlling for confounding (RR=0.73; 95% CI=0.70, 0.77 and RR=0.81; 95% CI=0.74, 0.89, respectively). Results were not modified by sex, race, psychiatric comorbidity, or neighborhood SES. Conclusions: Personal history of substance use disorder was independently associated with lower screening completion rates. Healthcare professionals should recognize unique barriers among individuals with substance use disorder and then address them individually as a multidisciplinary team in the outpatient setting to reduce this health disparity.