Maintaining adherence and retention in dementia prevention trials.

Incidence and prevalence of Alzheimer Disease (AD) will rise in a accelerating fashion through the middle of the 21st century. Increased understanding of the pathological cascades in AD, and the knowledge that the initial brain changes begin years prior to clinical manifestations, have led to initiation of trials to prevent AD. With many of the designs being used or contemplated, prevention trials will involve repeated cognitive and functional assessments over years, require cooperation and collaboration of both the subject and a partner or proxy, and represent a substantial time and resource investment by the research team. Compliance with the study regimen and adherence to the protocol are thus major foci for study efficiency and success. In this section methods by which compliance and adherence can be optimized are discussed. Research on the effectiveness of these and other evolving methods will be of help in assuring success of such large scale studies in the future.