Completing the colorectal cancer screening process: impact of eliminating cost-sharing for follow-up colonoscopy

Abstract

Introduction: Colorectal cancer (CRC) screening is recommended for average-risk adults, yet completion of the screening process requires follow-up colonoscopy after a positive stool-based test (SBT). Until recently, patients frequently faced out-of-pocket costs for follow-up colonoscopy, which was classified as a diagnostic procedure. In November 2022, coordinated federal policies were issued to eliminate patient cost-sharing for this procedure across commercial and Medicare insurance, effective January 2023. This study evaluated changes in follow-up colonoscopy utilization before and after implementation of these policies. Methods: We conducted a retrospective cohort study using a large, nationally representative health care claims resource linked with laboratory data from January 1, 2022, to December 1, 2023. Adults aged 45–75 years who underwent colonoscopy were included. Follow-up colonoscopy (a diagnostic colonoscopy performed within six months of a positive SBT) was the primary endpoint. An interrupted time series design with a seasonally adjusted segmented autoregressive model estimated changes before (January–December 2022) and after (January–November 2023) cost-sharing elimination. Results: Among 10,841,411 individuals undergoing colonoscopy, follow-up procedures comprised 3.59% (95% CI, 3.18–3.99) before implementation. Following policy enactment, there was an immediate 41.2% relative increase (absolute increase 1.48% [95% CI, 1.25–1.71]; p