Implementation pathways of the Diabetes Prevention Program in healthcare settings: a systematic review of barriers and facilitators

Type 2 diabetes (T2D) represents a major global health challenge due to rising prevalence and the associated healthcare costs. The Diabetes Prevention Program (DPP) has strong evidence of effectiveness in reducing T2D incidence; however, its implementation in healthcare settings remains suboptimal. Understanding barriers and facilitators to DPP implementation can contribute to successful integration and sustained delivery in real-world settings. This systematic review aimed to synthesize evidence on the barriers and facilitators (i.e., determinants) of DPP implementation in healthcare settings. We also examined how these determinants act along an implementation pathway, shaping implementation outcomes. We conducted a systematic review, reported in accordance with PRISMA 2020 guidelines and pre-registered in PROSPERO (CRD42024595128). Six databases (MEDLINE, CINAHL, PsycINFO, Embase, Web of Science, and Scopus) were searched from inception to December 2025. Eligible studies used qualitative, quantitative, and mixed method designs and reported determinants of DPP implementation in healthcare settings. Determinants were classified using the constructs of the Consolidated Framework for Implementation Research (CFIR) and the Integrated Behavior Model (IBM), while implementation outcomes were analyzed and organized according to the RE-AIM framework (reach, adoption, implementation, maintenance) and Proctor’s taxonomy (feasibility, acceptability, appropriateness). Study quality was assessed using the Mixed-Methods Appraisal Tool (MMAT). Twenty-one studies from the United States were included, employing qualitative, quantitative or mixed-methods and capturing perspectives of both individuals involved in implementation and innovation recipients. We mapped identified determinants to CFIR and IBM constructs and organized them along an implementation pathway showing how intermediate outcomes (feasibility, acceptability, and appropriateness) were linked to subsequent RE-AIM outcomes at both the setting and individual level. At the setting level, inner setting capacity constructs, including staffing, relative priority given to DPP, infrastructure, and referral systems were most consistently associated with feasibility, which was in turn related to adoption, implementation, and maintenance. Acceptability and appropriateness perceptions of individuals involved in implementation were associated with knowledge, perceived complexity, and trust in the evidence supporting the DPP, with implications for adoption and fidelity. At the individual level, reach was primarily associated with access barriers (costs, transport, scheduling, childcare) and cultural mismatches among recipients, with implications for equity. Understanding DPP implementation pathways may clarify how determinants operate through dynamic intermediate outcomes (feasibility, acceptability and appropriateness) and how these, in turn, are linked to adoption, implementation, reach and maintenance. Integrating these perspectives enables a coherent linkage between contextual determinants, intermediate outcomes, and implementation outcomes. This approach helps identify and tailor implementation strategies to support the equitable scale-up and sustainment of the DPP in routine healthcare settings.