Trends and inequities in colorectal cancer screening participation in Ontario, Canada, 2005-2011.

BACKGROUND: Participation in screening tests for colorectal cancer (CRC) is generally low in Ontario, Canada. In addition, inequities in participation exist including lower participation among low-income individuals, males and individuals living in rural areas. In April 2008, Colon Cancer Check (CCC) program, the province-wide CRC screening program, was launched in Ontario. This study describes the trends and inequities in CRC screening participation three years before and three years after the CCC, and assesses the effect of the program on CRC screening participation, overall and among certain population groups.

METHODS: We used administrative data to identify cohorts of individuals eligible for CRC screening in fiscal years 2005-2011. We calculated the age-standardized percent of Fecal Occult Blood Test (FOBT) participation, large bowel endoscopy participation, and being 'up-to-date' with CRC screening tests.

RESULTS: From 2005 to 2011, FOBT participation increased from 7.6% to 14.8%, large bowel endoscopy participation from 3.4% to 5.7%, and 'up-to-date' with CRC screening from 27.2% to 41.3%. Before the launch of the CCC program, the quarterly increase in FOBT participation was 0.07% (p=0.19), increased immediately after the launch (1.8%, p<0.01), followed by a decline (-0.08%, p=0.08), returning to its pre-program increase rate. We noted a significant decrease in FOBT participation every summer (-0.44%, p<0.01). The CCC program had minimal effect on large bowel endoscopy participation. Before the launch of the CCC program, the quarterly increase in 'up-to-date' with CRC screening was 0.9% (p<0.01), increased immediately after the launch (2.5%, p=0.05), followed by a modest decline thereafter (-0.59%, p<0.02). From 2005 to 2011, recent residents living in low-income neighborhoods were consistently and significantly less likely to have a FOBT and be 'up-to-date' with CRC screening than long-term residents living in high-income neighborhoods (2.9-4.5%; 14.7-17.3% respectively). Pre-CCC inequities in CRC participation persisted after the launch of the program.

CONCLUSION: CRC testing was increasing in Ontario from 2005. An immediate increase in CRC testing, FOBT in particular, occurred after the launch of the CCC program, followed by a return to its pre-CCC increase rate thereafter. Future efforts are needed to improve screening participation and address inequities.