Beyond Translation: a Systems Congruence Framework for Implementing Type 2 Diabetes Guidelines in Primary Healthcare Across Sub-Saharan Africa and Southeast Asia: a Systematic Review

Despite the availability of evidence-based clinical guidelines for type 2 diabetes mellitus (T2DM), their implementation in primary healthcare remains inconsistent across low- and middle-income countries (LMICs), particularly in Sub-Saharan Africa (SSA) and Southeast Asia (SEA). Implementation efforts frequently fail to account for the structural realities of health systems, resulting in limited sustainability and suboptimal patient outcomes. To develop an empirically grounded taxonomy of implementation strategies for T2DM care in the SSA and SEA countries represented in this review, and to propose a design-oriented conceptual framework, Systems Congruence complementing existing diagnostic frameworks (CFIR, PARIHS) by specifying structural alignment principles for resource-constrained healthcare settings. Following PRISMA 2020 guidelines, we systematically searched PubMed, Embase, CINAHL, Scopus, and Google Scholar for studies published between 2000 and 2024. Eligible studies reported implementation strategies for T2DM guidelines in primary healthcare settings in SSA or SEA. Data were extracted and study quality was appraised using Cochrane RoB 2, ROBINS-I, and MMAT tools. An inductive thematic synthesis was conducted to construct an implementation strategy taxonomy and derived an explanatory conceptual framework. Twenty-one studies from SSA and SEA (n = 14,281 participants) met the inclusion criteria. Nine distinct categories of implementation strategies were identified, including educational interventions, task-shifting, digital health, and culturally integrated approaches. Strategies demonstrating Systems Congruence, defined as intentional alignment with workforce capacity, the resource ecosystem, and patient context, were associated with substantial retention and adherence, reaching up to 94–100