Dose–response research in digital health interventions: Concepts, considerations, and challenges.

, prescriptions to engage in behaviors outside the intervention, such as changing food intake or meditating. Each type of prescription has both an intended dose (i.e., what the intervention actually prescribes) and an enacted dose (i.e., what portion of the intended dose is actually completed by the participant). Dose parameters of duration, frequency, and amount can be applied to each prescription type. We consider adaptive interventions and interventions with ad libitum prescriptions as examples of tailored doses. Researchers can experimentally manipulate the intended dose to determine the dose-response relationship. The enacted dose cannot be directly manipulated; however, we consider the applicability of "controlled concentration" research design to the study of enacted dose. We consider challenges in dose-response research in digital health interventions, including characterizing amount with self-paced activities and combining doses across modality. The presented concepts and considerations may help contribute to the optimization of digital health interventions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).