Background: Implementation science has focused mainly on the initial uptake and use of evidence-based practices (EBPs), with less attention to sustainment-i.e., continuous use of these practices, as intended, over time in ongoing operations, often involving adaptation to dynamic contexts. Declining EBP use following implementation is well-documented yet poorly understood. Using theories, models, and frameworks (TMFs) to conceptualize sustainment could advance understanding. We consolidated knowledge from published reviews of sustainment studies to identify TMFs with the potential to conceptualize sustainment, evaluate past uses of TMFs in sustainment studies, and assess the TMFs' potential contribution to developing sustainment strategies.
Methods: We drew upon reviews of sustainment studies published within the past 10 years, evaluated the frequency with which included articles used a TMF for conceptualizing sustainment, and evaluated the relevance of TMFs to sustainment research using the Theory, Model, and Framework Comparison and Selection Tool (T-CaST). Specifically, we examined whether the TMFs were familiar to researchers, hypothesized relationships among constructs, provided a face-valid explanation of relationships, and included sustainment as an outcome.
Findings: Nine sustainment reviews referenced 648 studies; these studies cited 76 unique TMFs. Only 28 TMFs were used in more than one study. Of the 19 TMFs that met the criteria for T-CaST analysis, six TMFs explicitly included sustainment as the outcome of interest, 12 offered face-valid explanations of proposed conceptual relationships, and six identified mechanisms underlying relationships between included constructs and sustainment. Only 11 TMFs performed adequately with respect to all these criteria.
Conclusions: We identified 76 TMFs that have been used in sustainment studies. Of these, most were only used once, contributing to a fractured understanding of sustainment. Improved reporting and use of TMFs may improve understanding of this critical topic. Of the more consistently used TMFs, few proposed face-valid relationships between included constructs and sustainment, limiting their ability to advance our understanding and identify potential sustainment strategies. Future research is needed to explore the TMFs that we identified as potentially relevant, as well as TMFs not identified in our study that nonetheless have the potential to advance our understanding of sustainment and identification of strategies for sustaining EBP use.
Keywords: Sustainability; Sustainment; Systematic reviews; Theories, models, and frameworks.