Prevalence of colonoscopy before age 50

• In 2010 more than 7.9% of insured individuals had colonoscopy between the ages of 40 and 49.
• Colonoscopy between the ages of 40 and 49 increased significantly from 1999 to 2010.
• Colonoscopy between the ages of 40 and 49 was more likely for women than men.
• Colonoscopy between the ages of 40 and 49 was most common in the Northeastern U.S.

ObjectiveDescribe the prevalence of colonoscopy before age 50, when guidelines recommend initiation of colorectal cancer screening for average risk individuals.MethodWe assembled administrative health records that captured receipt of colonoscopy between 40 and 49-years of age for a cohort of 204,758 50-year-old members of four US health plans and used backward recurrence time models to estimate trends in receipt of colonoscopy before age 50 and variation in early colonoscopy by age and sex. We also used self-reported receipt of colonoscopy from 27,157 40- to 49-year-old respondents to the 2010 National Health Interview Survey (NHIS) to estimate the association between early colonoscopy and sex, race/ethnicity, and geographic location based on logistic regression models that accounted for the complex NHIS sampling design.ResultsAbout 5% of the health plan cohort had a record of colonoscopy before age 50. Receipt of early colonoscopy increased significantly from 1999 to 2010 (test for linear trend, p < 0.0001), was more likely among women than men (RR = 1.9, 95% CI 1.14–1.24) and in the east coast health plan compared to west coast and Hawaii plans. The NHIS analysis found that early colonoscopy was more likely in Northeastern residents compared to residents in the West (odds ratio = 1.75, 95% CI 1.28–2.39).ConclusionColonoscopy before age 50 is increasingly common.