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

BACKGROUND:: 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. METHODS:: 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. RESULTS:: 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). CONCLUSIONS:: 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.