Completion of Colonoscopy After Positive Fecal Occult Blood Test Screening at a Community Health Center

Abstract

Introduction

Screening for colorectal cancer decreases mortality. Fecal occult blood testing (FOBT) decreases some barriers to screening, however positive results require colonoscopy. We evaluated factors associated with colonoscopy completion for community health center (CHC) patients after positive FOBT.

Methods

We identified patients of one CHC with positive FOBT from 1/1/2018-12/31/2021. We performed chart reviews for demographics, insurance status, FOBT date, colonoscopy referral date and site, and colonoscopy results.

We performed descriptive analysis. We fitted a logistic model and employed stepwise selection to evaluate effect of variables influencing likelihood of colonoscopy. We employed forward and backward model selection to identify the reduced model with the lowest Akaike Information Criterion score. Using this model, we calculated hypothesis tests for each coefficient using Wald tests with an alpha level of 0.05.

Results

Overall, 50% of participants completed colonoscopy. Mean time between positive FOBT and colonoscopy completion was 237.4 days (SD 187.9). The reduced logistic model included age and health insurance covariates. Insured patients were 221.7% more likely to complete colonoscopy than uninsured patients. A seven-year increase in age was associated with 41.2% increase in likelihood of colonoscopy. An increase of 38 miles to the colonoscopy site was associated with 17.7% decrease in likelihood of completion.

Conclusions

Only half of participants with positive FOBT completed colonoscopy. On average, nearly eight months elapsed between FOBT and colonoscopy. Having insurance was the strongest predictor of colonoscopy, despite available financial aid programs. Longer distances to colonoscopy sites decreased likelihood of completion.