BACKGROUND: Randomized trials have been criticized for being more protocol than participant-centered, with concerns raised about higher subject attrition and limited generalizability under controlled conditions. Informal caregivers are similar to other participants in community-based trials: many are unlikely to remain in a trial without procedural adaptations to meet some of their needs. PURPOSE: This article discusses design and statistical strategies for tracking potential confounds associated with 3 participant-centered adaptations that may be made in community-based caregiver trials: tailoring multi-component interventions, using interpersonal contacts for participant maintenance, and non-blinding of trial participants. The intent of the article is to initiate dialogue on the seldom-discussed issue of participant-centered adaptations in community-based trials. CONCLUSIONS: Participant-centered adaptations may reduce subject attrition and enhance generalizability, but protocol adaptation can compromise trial integrity. The challenge for investigators is to develop scientifically sound methods for tracking / controlling potential confounds associated with each adaptation.