Subject-reported compliance in a chemoprevention trial for familial adenomatous polyposis.

A high level of compliance with an assigned treatment regimen is fundamental to accurate assessment of treatment effectiveness in any clinical trial. If compliance is poor, an effective treatment may be confounded by inadequate delivery of the regimen. Although much research has focused on broad aspects of compliance dealing with clinical therapeutic situations, there was a need for further research dealing specifically with adherence issues in a long-term chemoprevention trial since subject motivation in the latter is likely to differ from that of the former. Examining subject-reported compliance over the first 2-year treatment periods of a long-term chemoprevention trial for familial adenomatous polyposis, it was found that (1) compliance decreased over time, (2) fiber compliance was lower than vitamin compliance, and (3) four explanatory variables which may be amenable to individualized study-team interventions emerged as useful prognosticators of fiber compliance.