Epidemiology of Colon Cancer Screening in a Safety-Net Setting

This study was aimed to describe the epidemiology of colon cancer screening in an underserved population. This is a cohort study, conducted in a primary care clinic in a safety-net public hospital.

Patients aged 49-78 years were categorized by initial screening status and followed over 28 months. Status was categorized into the following 3 groups with 8 subgroups: screening eligible (up to date or not up to date), non-screening eligible (Personal history of colon cancer, surveillance for colon cancer, work-up in progress, poor health status, and indeterminate), and refusal. Patient egress was defined as no primary care visit for 12 months or <2 primary care visits separated by 60 days over 24 months.

Of 1,074 patients reviewed, 856 (80%) were screening eligible, 177 (16%) were non-screening eligible, and 41 (4%) refused screening. Over 28 months, most patients retained in the practice did not change category (n=949; 88%). Of 125 patients who changed, most (n=101) went from screening eligible to non-screening eligible, most commonly to surveillance and work-up in progress subgroups. Egress was common; nearly half of patients (47%) were not evaluated owing to egress.

Maintaining a colon cancer registry was complex owing to the dynamic nature of screening status and unstable primary care attendance. Regional integration of electronic health records could substantially reduce manual effort.