Informing the dosing of interventions in randomized trials

Dosing is potentially the most important decision that must be made when building or refining behavioral interventions. In this paper, we propose standardized terminology and reporting of dosing information, which would inform intervention development, refinement for dissemination, and systematic reviews of dose-response relationships. Dosing of interventions may be characterized by duration, frequency, and amount. To illustrate the value of operationalizing these three parameters to evaluate dose-response relationships, 31 published reports of behavioral interventions to increase adherence to antiretroviral therapy (ART) were reviewed. The ART literature was characterized by under-reporting of dosing parameters, heterogeneity in dosing schedules, and heterogeneity in type of control group, which complicate analysis of dose-response relationships in systematic review and determination of the optimal dose for intervention dissemination. Improved reporting of the three dosing parameters and comparison of intended to actual delivery can inform the identification of the most effective intervention doses and the efficient implementation of efficacious interventions in clinical practice.