Background — Since the publication of two randomized controlled trials (RCT) in 1996 demonstrating the effectiveness of fecal occult blood test (FOBT) in reducing colorectal cancer (CRC) mortality, several public health initiatives have been introduced in Ontario to promote FOBT participation. The authors examined the effect of these initiatives on FOBT participation and evaluated temporal trends in participation between 1994 and 2012.
Method — Using administrative databases, the authors identified 18 annual cohorts of individuals age 50 to 74 years eligible for CRC screening and identified those who received FOBT in each quarter of a year. We used negative binomial segmented regression to examine the effect of initiatives on trends and Joinpoint regression to evaluate temporal trends in FOBT participation.
Results — Quarterly FOBT participation increased from 6.5 per 1000 in quarter 1 to 41.6 per 1000 in quarter 72 (January-March 2012). Segmented regression indicated increases following the publication of the RCTs in 1996 (Delta slope = 6%, 95% CI = 4.3-7.9), the primary care physician financial incentives announcement in 2005 (Delta slope = 2.2%, 95% CI = 0.68-3.7), the launch of the ColonCancerCheck (CCC) Program (Delta intercept = 35.4%, 95% CI = 18.3-54.9), and the CCC Program 2-year anniversary (Delta slope = 7.2%, 95% CI = 3.9-10.5). Joinpoint validated these findings and identified the specific points when changes occurred.
Conclusion — Although observed increases in FOBT participation cannot be definitively attributed to the various initiatives, the results of the two statistical approaches suggest a causal association between the observed increases in FOBT participation and most of these initiatives.
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