Patterns of colorectal cancer screening uptake in newly eligible men and women

Background: We describe patterns of colorectal cancer screening uptake in a U.S. insured population as individuals become newly eligible for screening at age 50 and assess temporal trends and patient characteristics with screening uptake.

Methods: We identified a cohort of 81,223 men and women who were members of Group Health and turned 50 years old from 1996 to 2010. We ascertained receipt of colorectal cancer screening within five years. Time to screening was estimated by year of cohort entry using cumulative incidence curves and Cox proportional hazards models-estimated patient characteristics associated with screening uptake.

Results: Stool-based screening tests were the most common, 72% of first screening tests. The proportion of individuals initiating colorectal cancer screening via colonoscopy increased from 8% in 1996 to 1998 to 33% in 2008 to 2010. Patient factors associated with increased colorectal cancer screening were: turning 50 more recently (2008-2010; Ptrend < 0.0001) or Asian race [HR, 1.14; 95% confidence interval (CI), 1.10-1.19]. Patient factors associated with decreased screening were: being a woman (HR, 0.70; 95% CI, 0.68-0.72), Native American (HR, 0.68; 95% CI, 0.60-0.78), or Pacific Islander race (HR, 0.82; 95% CI, 0.72-0.95), and having prevalent diabetes (HR, 0.78; 95% CI, 0.75-0.82) and higher body mass index (Ptrend < 0.0001).

Conclusions: Patient characteristics associated with initiation of colorectal cancer screening in a newly eligible population are similar to characteristics associated with overall screening participation in all age-eligible adults. Our results identify patient populations to target in outreach programs.

Impact: Disparities in receipt of colorectal cancer screening are evident from onset of an age-eligible cohort, identifying key groups for future interventions for screening.