Non-compliance with the initial screening exam visit in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial

Abstract

ObjectiveIdentify predictors of non-compliance with first round screening exams in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. MethodThe PLCO was conducted from 1993 to 2011 at 10 US institutions. A total of 154,897 healthy men and women ages 55–74years were randomized. Intervention arm participants were invited to receive gender-appropriate screening exams for prostate, lung, colorectal and ovarian cancer. Using intervention-arm data (73,036 participants), non-compliance percentages for 13 covariates were calculated, as were unadjusted and adjusted odds ratios (ORs), and 95% confidence intervals. Covariates included demographic factors as well as factors specific to PLCO (e.g., method of consent, distance from screening center). ResultsThe rate of non-compliance was 11% overall but varied by screening center. Significant associations were observed for most covariates but indicated modest increases or decreases in odds. An exception was the use of a two-step consent process (consented intervention arm participants for exams after randomization) relative to a one-step process (consented all participants prior to randomization) (OR: 2.2, 95% CI: 2.0–2.5). Non-compliance percentages increased with further distance from screening centers, but ORs were not significantly different from 1. ConclusionsMany factors modestly influenced compliance. Consent process was the strongest predictor of compliance.