Hybrid type 1 effectiveness-implementation studies: why and how to do them

Effectiveness-implementation hybrid type 1 studies primarily investigate the effectiveness of an intervention and have a secondary focus on exploring implementation-related factors. Integrating implementation aims into intervention effectiveness studies can improve the speed, quantity, and quality of intervention implementation, sustainment, and scale in routine practice, and thereby maximize the impact on population health. This article provides guidance for designing and conducting the implementation aims of effectiveness-implementation hybrid type 1 studies, summarizing past thinking and advancing new considerations for these approaches. The authors argue that hybrid type 1 approaches are suitable for most types of intervention effectiveness research (e.g., efficacy trials, comparative-effectiveness research, observational studies), for different kinds of interventions (e.g., treatment, screening, prevention), and in a broad range of settings (e.g., healthcare, public health, community, schools). The article offers methodological guidance for designing the implementation aims of hybrid type 1 studies, structured around three goals: (1) explain intervention implementation in the effectiveness trial, (2) explore stakeholder perceptions to inform future implementation research, and (3) examine stakeholder perceptions to inform the effectiveness trial. Each of these goals offers a distinct set of research questions and design considerations (e.g., timing, sampling, data collection). Finally, the authors provide some tools and resources for planning and designing hybrid type 1 studies.