Demographic and comorbidity predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program: a nationwide cross-sectional study

Mette Kielsholm Thomsen,1 Morten Rasmussen,2 Sisse Helle Njor,1,3 Ellen Margrethe Mikkelsen1 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Digestive Diseases K, Bispebjerg Hospital, Copenhagen, Denmark; 3Department of Public Health Programs, Randers Regional Hospital, Randers, Denmark Background: Predictors of participation in colorectal cancer screening with a stool sample screening modality have been widely studied, but adherence to subsequent diagnostic colonoscopy after a positive screening test has received less attention. We aimed to determine predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program.Methods: We conducted a cross-sectional study using data from National Health Service registries. We included 8,112 individuals invited to screening between March 3, 2014, and August 31, 2014, who had a positive immunochemical fecal occult blood test. Potential predictors were gender, age, region of residence, Charlson Comorbidity Index (CCI) score, specific diseases (cardiovascular disease, chronic pulmonary disease, diabetes, and cancer), and number of prior hospital stays. We estimated prevalence proportion differences (PPDs) for the associations between potential predictors and adherence.Results: Overall, adherence to diagnostic colonoscopy was 88.6%. Adherence was lower in individuals aged 75 years compared with those aged