Comparative effectiveness of initiating colorectal cancer (CRC) screening (Scr) at age 45.

Abstract

531 Background: The incidence of CRC in age group 45-50 is rising based on SEER data. We investigated the outcomes of lowering Scr age to 45 from a societal perspective. Methods: A Markov model was built to represent the natural history and incidence of CRC in US general population (GP). Individual level simulation was used to compare 14 Scr strategies (ST). Effectiveness in life years (LY) & number of prevented (Prev) CRCs, and costs in US$ ($) inclusive of CRC Scr and treatment were measured. LY and $ were discounted at 3%. Incremental cost effectiveness ratios (ICERs) were calculated. Individuals in a cohort of GP aged 45-75 were followed for up to 35 years with Scr starting at age 50 (@50) or 45 (@45). Results: Colonoscopy (CS) @50 ranked 1 with the highest LY and lowest $ & ICER followed by CS @45 (ranked 2) with an ICER of $23074. All other STs had lower LY & higher $ and were dominated by CS. By starting Scr @45, the number of Prev CRC increased favoring Scr @45. LY changes were minimal but favored Scr @45. When CS was removed from Scr options, Fecal Occult Blood Test (FOBT) @45, CT Colonography (CT) every 10 years @50 and CT every 5 years @45 dominated remaining STs with ICERs of $0, $5585, and $31058, respectively. When CT and FOBT were removed from Scr options, FOBT+FS @45 and DNA @45 dominated remaining STs with ICERs of $0 and $650790, respectively. Results remained stable in sensitivity analyses. Conclusions: LY, Prev CRC improved as a result of Scr @45. When dominating STs were sequentially removed, STs beginning @ 45 remained cost effective with ICERs of <$50,000. The advantages of @45 are the result of earlier start and longer duration of Scr. Of note, DNA was not cost effective with ICER of >$650K after CS and CT were removed from calculations. [Table: see text]