The Design of Hybrid Type 2 Studies

Oregon Convention Center 

Hybrid type 2 designs enable the concurrent examination of both effectiveness and implementation outcomes, emphasizing equal importance of these two outcomes. However, these designs pose statistical challenges, especially in cluster randomized trials (CRTs). Standard methods for powering studies can be inadequate in this context. This work explores methodologies for validly powering hybrid type 2 studies in a CRT setting. A literature search revealed 18 relevant publications, identifying five methods, two of which are extended here to address clustering—the combined outcomes approach and single 1-degree of freedom combined test. We describe and illustrate procedures for powering studies using these methods, drawing inspiration from a Chicago Implementation Research Center (CIRCL) study on blood pressure control and reach. The conjunctive test's hypothesis setup aligns with the research goals, yielding lower sample size requirements compared to popular p-value adjustment methods.