Colorectal Cancer Screening

Abstract

To the Editor To inform the recently updated guidelines from the US Preventive Services Task Force (USPSTF) on colorectal cancer (CRC) screening,¹ Dr Lin and colleagues conducted a meta-analysis of randomized trials of different screening interventions, including flexible sigmoidoscopy.² Unfortunately, the authors pooled different age groups in the Norwegian Colorectal Cancer Prevention Trial (NORCCAP)³ to calculate the summary mortality estimate for flexible sigmoidoscopy screening. Methodologically, we do not think this approach is correct because pooling the age groups introduced confounding by age.