Recruitment and retention rates in behavioral trials involving patients and a support person: a systematic review.

Background: Recruitment and retention challenges impede the study of behavioral interventions among patient-support person dyads.

Purpose: The aim of the study was to characterize recruitment and retention rates of behavioral interventions involving dyads.

Methods: Using PRISMA guidelines and with the guidance of a medical librarian, we searched Medline, EMBASE, Cochrane Controlled Trials, PsycInfo, and CINAHL from inception until July 2011.