Optimizing screening with faecal immunochemical test for both sexes Cost-effectiveness analysis from Finland

A faecal immunochemical test (FIT) screening pilot was introduced in Finland in 2019 with sex-specific screening strategies. This study aims to model cost-effectiveness of sex-specific strategies for the whole population, and to assess whether the current strategies are optimal. We developed separate MISCAN-Colon models, including different FIT performances, for the Finnish men and women using the first-year data of the FIT screening pilot. We evaluated 180 FIT strategies varying in FIT cut-off, screening interval, age to start, and age to stop screening, and compared them to no-screening by sex. We used incremental cost-effectiveness ratios (ICERs) to identify the optimal strategy after combining all male and female strategies and restricting the analysis by costs and referral rate to diagnostic colonoscopies. Offering annual FIT screening with a cut-off of 25 mu g/g at 50-79 years in men and with a cut-off of 10 mu g/g at 55-69 years in women was optimal. This combined strategy prevented 28% of colorectal cancer (CRC) cases and 55% of CRC deaths with acceptable costs (ICER = 9000 epsilon/life-years gained). Screening at the current target age of 60-74 years was suboptimal for both sexes. Among strategies with the same target age and interval for both sexes, expected benefits from optimal screening were lower but still reasonable. Our results support a wider age range of screening in men, and a lower cut-off for a positive test in women when restrictions on colonoscopy capacity and costs are in place. National FIT screening program should start at younger age.

Automated summary

This study modeled the cost-effectiveness of sex-specific FIT screening strategies in Finland and evaluated the optimal strategies. The results showed that annual FIT screening with a cut-off of 25μg/g for men aged 50-79 and with a cut-off of 10μg/g for women aged 55-69 was optimal. This strategy significantly reduced the incidence and mortality of colorectal cancer.