Efficient Population-based Colorectal Cancer Screening in Shenzhen: A Microsimulation Modelling study

Abstract Background Colorectal cancer (CRC) is a global health issue with noticeable high incidence and mortality. Microsimulation models offer a time-efficient method to dynamically analyze multiply intervention strategies. The study aimed to identify the efficient population-based CRC screening strategies for Shenzhen city. Methods A microsimulation model named CMOST was used to simulate CRC screening among one million population without migration in Shenzhen, with two CRC developing pathways and participation rates in real world. Questionnaire-based risk assessment models, fecal immunochemical test (FIT), and Risk-stratification model (RS model) as initial screening were simulated, followed by diagnostic colonoscopy. Several start-ages (40, 45, 50 years), stop-ages (70, 75, 80 years), and intervals (annal, biennial, triennial) for each screening strategy were assessed. The efficiency of CRC screening was analyzed by Data Envelopment Analysis method. Results The screening strategies reduced CRC incidence by 14–27 cases (30.1–58.4%) and mortality by 11–21 deaths (33.1–63.0%), yielded 121–283 life-years gained (LYG), while required 860 to 5868 colonoscopies per 1000 individual. Among the total of 135 screening strategies, 23 were estimated efficient. Most of the efficient screening strategies were those starting at age 40 years (17 out of 23 strategies) and stopping at age 70 (also 17 out of 23 strategies). The estimated efficiency ratios of efficient screening starting at age 40 were closed to those starting at age 45 and the estimated increase in LYG from extending screening beyond age 70 years was small in comparison with the increase in colonoscopies. The efficiency ratios increased with shorter intervals. For triennial screening from age 40 to 70, the colonoscopies per LYG increased progressively for FIT (6.7), Asia Pacific Colorectal Screening score (8.3) and RS model (13.8). Conclusion This study suggests that CRC screening performs from ages 40 to 70 years for average risk population in Shenzhen, and triennial FIT is an optimal strategy.