Summary: | Background: This thesis is composed of three studies testing the effect of the Colon Cancer Check (CCC) program, the organized screening program for colorectal cancer in Ontario, on screening participation. In the first paper, we described the trends of participation to Fecal Occult Blood Test (FOBT) and endoscopy, and the trend of ‘up-to-date’ consistent with guidelines, overall and stratified by demographic characteristics between 2005 and 2011. In the second paper, we tested the effect of physician’s recommendation on FOBT participation and disparities in participation. In the third paper, we measured the effect of the CCC program on FOBT participation using an interrupted time series.
Methods: We identified six annual cohorts of individuals eligible for CRC screening in Ontario between 2005 and 2011 by linking the Registered Persons Database to Ontario Health Insurance Plan and 2006 Census from Statistics Canada. We used descriptive statistics to describe the trends of participation. The effect of physician’s recommendation on screening participation was tested using multiple logistic regression analysis. The effect of the CCC program on FOBT participation was tested using segmented regression analysis.
Results: An increasing trend in FOBT participation and ‘up-to-date’ status was observed across all demographic characteristics. The disparity gaps persisted over time by gender, income, recent registrant and age. The rural/urban gap was removed. Physician’s recommendation tripled the likelihood of FOBT participation (prevalence rate ratio=3.23, CI= 3.22-3.24) and mitigated disparities. The CCC led to a temporary increase in level (8.2‰ person-month) in FOBT participation followed by a decline in trend and then a plateau. The increase in level was significant across all population sub-groups.
Conclusions: We found that CRC screening has increased in Ontario across all subgroups of the population but remained suboptimal. Disparities in screening participation were identified. Proposed strategies to improve performance include interventions to increase the rate of physician’s recommendation at the practice level, tailored interventions to motivate under-users and public media campaigns.
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