Influence of Age and Comorbidity on Colorectal Cancer Screening in the Elderly

INTRODUCTION: Expert recommendations differ for colorectal cancer screening in the elderly. Recent studies suggest that healthy adults aged >75 years may benefit from screening. This study examined screening use and follow-up, and how they varied by health status within age strata, among a large cohort of elderly individuals in community settings. METHODS: A population-based, longitudinal cohort study was conducted among health plan members aged 65-89 years enrolled during 2011-2012 in three integrated healthcare systems participating in the Population-Based Research Optimizing Screening through Personalized Regimens consortium. Comorbidity measurements used the Charlson index. Analyses, conducted in 2015, comprised descriptive statistics and multivariable modeling that estimated age by comorbidity-specific percentages of patients for two outcomes: colorectal cancer screening uptake and follow-up of abnormal fecal blood tests. RESULTS: Among 846,267 patients, 72% were up-to-date with colorectal cancer screening. Of patients with a positive fecal blood test, 65% received follow-up colonoscopy within 3 months. Likelihood of being up-to-date and receiving timely follow-up was significantly lower for patients aged ≥76 years than their younger counterparts (p<0.001). Comorbidity was less influential than age and more strongly related to timely follow-up than being up-to-date. In all age groups, considerable numbers of patients with no/low comorbidity were not up-to-date or did not receive timely follow-up. CONCLUSIONS: In three integrated healthcare systems, many older, relatively healthy patients were not screening up-to-date, and some relatively young, healthy patients did not receive timely follow-up. Findings suggest a need for re-evaluating age-based screening guidelines and improving screening completion among the elderly.