This scoping review mapped and synthesised published evidence on the quality of care for adults with type 2 diabetes mellitus (T2DM) in Malaysian primary health care (PHC) settings. The review concentrated on three key clinical quality indicators—glycated haemoglobin (HbA1c), blood pressure (BP), and low-density lipoprotein cholesterol (LDL-C)—collectively referred to as ABC control. Two guiding questions framed the review: the characteristics of studies reporting ABC estimates in Malaysian PHC, and the reported measures and estimates of ABC control among adults with T2DM treated in PHC.
The review adhered to Joanna Briggs Institute (JBI) scoping review methodology and followed PRISMA-ScR reporting standards. A comprehensive search covered PubMed, Embase, Scopus and the Malaysian Medical Repository (MyMedR), supplemented by backward citation tracking and searches for relevant Ministry of Health (MOH) grey literature. Searches included records from database inception through 31 December 2024. EndNote was used for deduplication and Rayyan for screening.
Using the Population–Concept–Context (PCC) framework, the review included studies of adult patients (≥18 years) with T2DM reporting at least one ABC indicator in Malaysian PHC settings. Included evidence sources comprised peer-reviewed quantitative, qualitative, and mixed-methods studies, plus MOH technical reports. Exclusions were guidelines, reviews, editorials, conference abstracts, and studies restricted to narrow subpopulations only (e.g., older adults only, women only) to preserve system-level comparability.
Two reviewers independently screened titles/abstracts and full texts, with discrepancies resolved by discussion or third-reviewer adjudication. A piloted, standardised data extraction form captured study characteristics and ABC outcomes; extraction was performed independently by two reviewers. Extracted data were synthesised narratively. Because of heterogeneity in designs and outcome definitions, no formal meta-analysis was performed; visual displays (heatmaps, scatterplots, tables) were produced to summarise distributions and reported estimates.
The search retrieved 1,888 records; after deduplication and screening, 109 publications met inclusion criteria. The included literature spanned 1999–2024, with a substantial increase in publications after 2010, suggesting rising research and policy attention to T2DM care quality in Malaysia. Across the body of evidence, HbA1c was the most commonly reported indicator.
The geographic distribution of included studies was unequal, with a concentration in urban states. The available evidence maps detail state-level counts and indicate clustering of study sites rather than even national coverage, which may limit generalisability to less-represented regions. The authors highlighted Selangor as a notably represented state among publications.
Large-scale studies frequently relied on routine datasets, particularly the National Diabetes Registry (NDR), as well as other registry or administrative data. This dependence facilitated population-level estimates but also concentrated evidence around settings and populations captured by those registries.
Across included publications reporting HbA1c, achievement of a common target—HbA1c <7.0%—was suboptimal and showed no clear improvement over about two decades. Reported achievement rates clustered approximately between 30% and 45% across studies. Heterogeneity existed in reported thresholds and metrics (proportions meeting targets, means/medians), which was addressed by aggregating subgroup data when necessary for narrative presentation.
Reported BP control was likewise static and suboptimal over the review period. For combined BP targets commonly reported as <130/80 mmHg, achievement rates varied widely across studies but generally ranged from about 20% to 50%. As with HbA1c, differing target definitions and reporting formats contributed to heterogeneity in estimates.
In contrast to HbA1c and BP, LDL-C control (frequently reported against a threshold of ≤2.6 mmol/L) demonstrated modest improvement over time. Achievement rates increased from roughly 30% to about 50% across approximately one decade, indicating that measurable progress in at least one ABC domain is possible within the Malaysian PHC context.
The evidence base showed substantial heterogeneity in study designs, outcome definitions, and geographic coverage. Many studies reported multiple thresholds and site-level data, so counts across evidence maps could exceed the number of publications. Reliance on registry and routine data may bias findings toward settings with better data capture. By design, the scoping review excluded studies limited to specific subpopulations, which preserves system-level assessment but may underestimate inequities facing underserved groups. The authors did not conduct a meta-analysis because of these variations.
The review highlights a persistent gap between guideline-based targets and real-world ABC outcomes in Malaysian PHC, with HbA1c and BP control remaining largely unchanged and suboptimal, while LDL-C has shown modest gains. The authors recommend a balanced policy focus across all three ABC indicators, strategies to address systemic barriers within PHC, and continued investment in the National Diabetes Registry and other data systems to support evidence-based improvement. The findings identify clear priorities for research and service improvement, including more geographically representative studies, standardised outcome definitions, and investigations into the systemic drivers of poor glycaemic and BP control.