Purpose-guided trial design in health-related behavioral intervention research.

Purpose-guided trial design (PGTD) is a novel heuristic framework for planning randomized controlled trials of health-related behavioral interventions. Its use helps to ensure that the study design and the control or comparison group are compatible with the primary purpose of the trial. When used in conjunction with the recently developed pragmatic model for comparator selection in health-related behavioral trials (Freedland et al., 2019), the PGTD framework can help to resolve uncertainties, disagreements, and controversies about the comparators that are used in behavioral randomized controlled trials. For example, PGTD can help to answer questions about whether, when, and how to control for attention in behavioral trials. The PGTD framework can be used to evaluate published trials, but it is primarily intended for use as a behavioral trial planning tool. (PsycInfo Database Record (c) 2020 APA, all rights reserved).