Effects of screening and universal healthcare on long-term colorectal cancer mortality

Background: To evaluate the time trends of colorectal cancer (CRC) affected by a Nationwide Colorectal Cancer Screening (NCCS) programme with biennial faecal immunochemical testing (FIT) and Nationwide Healthcare Insurance (NHI). Methods: Data from the national registries on cancer and death in Taiwan were separated into years 1984-1993, 1994-2003 and 2004-2013 based on the implementations of NHI (starting 1995) and NCCS (starting 2004). The adult population was divided into three age groups (young, 30-49; middle-aged, 50-69; and old, 70-84 years); only the middle-aged were eligible for NCCS. Crude and adjusted effects of NCCS and NHI were quantified by percentage change and 95% confidence interval (CI) with respect to CRC mortality, according to the attributions from incidence and survival. Results: Within 335 million person-years of follow-up, 204 362 incident CRCs and 80 771 CRC-related deaths were identified. Increasing mortality trends were noted for 1994-2003 (post-NHI) vs 1984-1993 due to remarkable increasing incidence trends that could not be offset by improved survival as a result of NHI. During 2004-13 (post-NCCS), mortality continued to increase by 15% (95% CI: 10-21%) in young adults (30-49 years) and 8% (95% CI: 6-11%) in older adults (70-84 years), whereas middle-aged adults (50-69 years) had a reduction of 7% (95% CI: 5-9%) due to a remarkable stage shift and subsequent improvement in survival. In the middle-aged adults, increased incidence was less but survival improvement was more compared with other age groups. Conclusions: Whereas universal healthcare insurance led to improvement in CRC survival, FIT-based screening has made an even greater contribution to reducing CRC mortality. ? The Author(s) 2018. Published by Oxford University Press on behalf of the International Epidemiological Association.