Effectiveness-implementation hybrid designs: implications for quality improvement science

Abstract

Presentation This article summarizes the three types of hybrid effec-tiveness-implementation designs and associated evalua-tion methods. It includes a discussion of how hybrid designs have the potential to enhance knowledge devel-opment and application of clinical interventions and implementation strategies in " real world " settings. The authors propose implications of hybrid designs for qual-ity improvement research. Traditionally, researchers think of knowledge develop-ment and application as a uni-directional, step-wise, pro-gression, in which different questions are addressed in isolation. First, a randomized clinical trial (RCT) is deployed to determine if an intervention implemented under controlled conditions has efficacy in specific popula-tions. Next, " effectiveness research " methods determine if the effect remains when implemented in less controlled conditions with broader populations. Finally, " implementa-tion research " methods, such as cluster randomized con-trolled trials, are deployed to understand the best methods to introduce the intervention into practice. While systema-tic, this unidirectional approach can take a great deal of time from the original efficacy study design to the final conclusions about implementation, and conditions may change so that original clinical and policy questions become less relevant [1]. Additionally, the unidirectional approach does not help us understand interaction effects between the intervention and the implementation strategy. Hybrid designs simultaneously evaluate the impact of interventions introduced in real world settings (e.g. " effec-tiveness "), and the implementation strategy. Such designs enhance the ability to identify important intervention-implementation interactions, which inform decisions about optimal deployment and generalized impact, and may accel-erate the introduction of valuable innovations into practice. This has implications for quality improvement researchers, who are often guiding the deployment and evaluating the impact of interventions in healthcare settings. Types of hybrid designs Hybrid designs form a continuum between pure effective-ness research and pure implementation research, as defined above. Hybrid designs are best suited for the study of minimal risk interventions with at least indirect evi-dence of effectiveness, and strong face validity to support applicability to the new setting, population or delivery method in question. Each type describes two a priori aims: one for testing intervention effectiveness, and one for eval-uating the implementation strategy. The types differ according to the emphasis placed on testing the interven-tion or the implementation. These designs incorporate evaluation methods—process, formative and summative evaluation—which distinguish hybrid designs from tradi-tional effectiveness research but are typical of implementa-tion research. For more detailed examples of hybrid design in published research, please refer to Curran et al. [2]. Type 1 hybrid designs rigorously test the clinical inter-vention and secondarily gather data to inform subsequent implementation research trials. These studies measure patient functioning or symptoms in response to a clinical intervention, while simultaneously evaluating feasibility and acceptability of implementation through qualitative, process-oriented, or mixed methods. Type 2 hybrid designs simultaneously test the clinical intervention, while rigorously testing the implementation strategy. Ideal targets include populations or settings that are reasonably close to those studied in prior effectiveness trials. The use of fractional factorial designs can inform allo-cation of study groups in hybrid Type 2 studies. This design strategy allows for multiple " doses " of implementation