An international, Delphi consensus study to identify priorities for methodological research in behavioral trials in health research

Background Non-communicable chronic diseases are linked to behavioral risk factors (including smoking, poor diet and physical inactivity), so effective behavior change interventions are needed to improve population health. However, uptake and impact of these interventions is limited by methodological challenges. We aimed to identify and achieve consensus on priorities for methodological research in behavioral trials in health research among an international behavioral science community. Methods An international, Delphi consensus study was conducted. Fifteen core members of the International Behavioral Trials Network (IBTN) were invited to generate methodological items that they consider important. From these, the research team agreed a "long-list" of unique items. Two online surveys were administered to IBTN members (N = 306). Respondents rated the importance of items on a 9-point scale, and ranked their "top-five" priorities. In the second survey, respondents received feedback on others' responses, before rerating items and re-selecting their top five. Results Nine experts generated 144 items, which were condensed to a long-list of 33 items. The four most highly endorsed items, in both surveys 1 (n = 77) and 2 (n = 57), came from two thematic categories:"Intervention development" ("Specifying intervention components" and "Tailoring interventions to specific populations and contexts") and "Implementation" ("How to disseminate behavioral trial research findings to increase implementation" and "Methods for ensuring that behavioral interventions are implementable into practice and policy"). "Development of novel research designs to test behavioral interventions" also emerged as a highly ranked research priority. Conclusions From a wide array of identified methodological issues, intervention development, implementation and novel research designs are key themes to drive the future behavioral trials' research agenda. Funding bodies should prioritize these issues in resource allocation.