Abstract
BACKGROUND: Sustainment, an outcome indicating an intervention continues to be implemented over time, has been comparatively less studied than other phases of the implementation process. This may be because of methodological difficulties, funding cycles, and minimal attention to theories and measurement of sustainment. This review synthesizes the literature on sustainment measures, evaluates the qualities of each measure, and highlights the strengths and gaps in existing sustainment measures. Results of the review will inform recommendations for the development of a pragmatic, valid, and reliable measure of sustainment. METHODS: A narrative review of published sustainment outcome and sustainability measures (i.e., factors that influence sustainment) was conducted, including appraising measures in the Society of Implementation Research Collaboration (SIRC) instrument review project (IRP) and the Dissemination and Implementation Grid-Enabled Measures database initiative (GEM-D&I). The narrative review used a snowballing strategy by searching the reference sections of literature reviews and definitions of sustainability and sustainment. Measures used frequently and judged to be comprehensive and/or validated by a team of implementation scientists were extracted for analysis. RESULTS: Eleven measures were evaluated. Three of the included measures were found in the SIRC-IRP, three in the GEM-D&I database, (one measure was in both databases) and six were identified in our additional searches. Thirteen constructs relating to sustainment were coded from selected measures. Measures covered a range of determinants for sustainment (i.e., construct of sustainability) as well as constructs of sustainment as an outcome. Strengths of the measures included, development by expert panels knowledgeable about particular interventions, fields or contexts, and utility in specific scenarios. A number of limitations were found in the measures analyzed including inadequate assessment of psychometric characteristics, being overly intervention or context specific, being lengthy and/or complex, and focusing on outer context factors. CONCLUSION: There is a lack of pragmatic and psychometrically sound measures of sustainment that can be completed by implementation stakeholders within inner context settings (e.g., frontline providers, supervisors).