UC Irvine

This study identified participants' reasons for good, marginal or poor adherence, or withdrawing from community-based clinical studies using a dietary and/or drug intervention. Adults aged 48-75 years participated in one of three studies related to decreasing colon polyp recurrence. Qualitative data from progress notes (N = 675) and end-of-study evaluations (N = 87) were coded using constant comparative analysis with 100% content validity panel agreement. Most common reasons for non-adherence were barriers such as side-effects, interference with vacation plans, unrelated illness, forgetting and competing outside stressors. Participation motivators were benefits such as altruism, medical benefits, free service and staff rapport. Findings supported the Health Behavior in Cancer Prevention model-based approach to adherence interventions and provided directions for adherence promotion in future community-based clinical studies.