Lack of follow-up colonoscopy after positive FOBT in an organized colorectal cancer screening program is associated with modifiable healthcare practices

Background — Colon Cancer Check (CCC), Ontario's organized colorectal cancer (CRC) screening program, uses guaiac fecal occult blood testing (gFOBT). To reduce CRC-related mortality, persons with a positive gFOBT must have colonoscopy. We identified factors associated with failure to have colonoscopy within 6 months of a positive gFOBT.

Methods — Population-based, retrospective cohort analysis of CCC participants with positive gFOBT (April 2008 to December 2009) using health administrative data. Patient, physician and healthcare utilization factors associated with a lack of follow-up colonoscopy were identified using descriptive and multivariate analyses.

Results — There were 21,839 participants with a positive gFOBT; 14,091 (64%) had colonoscopy within 6 months. The strongest factors associated with failure to follow-up were recent colonoscopy (in 2 years prior vs. >10 years or never, OR: 4.31, 95% C.I.: 3.82, 4.86), as well as repeat gFOBT (OR: 6.08, 95% C.I.: 5.46, 6.78) and hospital admission (OR: 4.35, 95% C.I.: 3.57, 5.26) in the follow-up period.

Conclusion — In the first 18 months of the CCC Program, 1/3 of those with a positive gFOBT did not have colonoscopy within 6 months. Identification of potentially modifiable factors associated with failure to follow up lay the groundwork for interventions to address this critical quality gap.