Health Equity After a Colorectal Cancer Screening Program

Importance: Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer death globally. Early identification of precancerous lesions and early-stage cancers can substantially reduce CRC incidence and improve survival. Hong Kong launched an organized colorectal cancer screening program (CRCSP) for the population in 2016. Objective: To assess the association of the CRCSP with the health equity of cancer screening participation among different socioeconomic groups over a 9-year period. Design, Setting, and Participants: Individual-level data from adults aged 50 to 75 years were analyzed from 3 repeated territory-wide population surveys in Hong Kong, China, between December 2014 to January 2022 to track trends in fecal test and colonoscopy participation. Disparities in screening uptake by socioeconomic status and income were assessed by concentration curves and indices. Survey-weighted generalized logistic regression models were used to assess the association between screening participation and socioeconomic factors. Data were analyzed from January 2025 to March 2026. Main Outcomes and Measures: Colorectal cancer screening utilization, specifically having ever undergone (1) a fecal test without symptoms and (2) a colonoscopy without symptoms. Results: This study analyzed 14 602 adults aged 50 to 75 years (mean SD age, 60.62 7.03 years; 7716 female individuals 52.84%). Participation in fecal testing increased from 19.88% (95% CI, 18.70-21.05) from 2014 to 2015 to 27.15% (95% CI, 26.12%-28.18%) from 2020 to 2022, and colonoscopy uptake rose from 17.65% (95% CI, 16.53%-18.77%) to 27.28% (95% CI, 26.24%-28.31%). Socioeconomic disparities narrowed after the CRCSP, with the concentration indices declining (fecal test participation, 0.11 from 2014-2015 to 0.02 from 2020-2022). Similar improvements were found for colonoscopy screening and across income groups. Screening participation was significantly associated with older age, higher education level, marital status, private housing, income, and socioeconomic status. Conclusions and Relevance: In this cross-sectional study, following the implementation of an organized population screening program, colorectal cancer screening participation increased and socioeconomic disparities narrowed over time. Overall uptake in Hong Kong remains low, and some disparities persist in younger age groups (age 50-59 years), single households, individuals with a primary and secondary school education, lower-income groups, and public housing residents. Efforts to increase participation are needed in certain groups to ensure health equity.