Age-based and sex-based disparities in screening colonoscopy use among medicare beneficiaries

The use of screening colonoscopy among older persons is controversial due to variability in life expectancy and sex-based differences in colorectal cancer incidence. We assessed the relation between sex, age, and receipt of screening colonoscopy overall and within strata of life expectancy.

We used Medicare data to identify beneficiaries during the years 2001 to 2005 who had not undergone a colonoscopy in the prior 3 years. Medicare claims were used to identify screening colonoscopy use; life expectancy was estimated using a life table approach. We used Poisson regression to examine sex and age differences in screening colonoscopy, adjusted for patient demographic characteristics.

Our sample consisted of 161,229 patients (61.9% female; mean age 76.9 y). The screening colonoscopy rates for females and males were 16.9 and 24.4 screening colonoscopies per 1000 person-years, respectively (P<0.001). The screening colonoscopy rate was highest for patients with the longest life expectancy (10 to 15 y: 27.2 screening colonoscopies per 1000 person-years) compared with 3.4 per 1000 person-years in the life expectancy <5-year group. Within specific life expectancy categories, older patients had significantly lower screening rates; in the 10- to 15-year life expectancy category, patients 75 to 79 years old had a lower rate (21.9 screening colonoscopies per 1000 person-years) than patients 68 to 69 years old (34.1 screening colonoscopies per 1000 person-years; P<0.001).

In a large cohort of Medicare beneficiaries, there was evidence of screening colonoscopy use even among patients with a short life expectancy. After accounting for life expectancy, females and older persons were less likely to undergo screening colonoscopy.