Efficacy of Community-based Interventions in Reducing HbA1c Levels Among Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Recent Studies Conducted in Developing Countries

Abstract

Background: Type 2 Diabetes Mellitus (T2DM) presents a significant public health challenge, particularly in developing countries, where healthcare resources are limited. Community-Based Interventions (CBIs) have been explored as a strategy to improve glycemic control, yet evidence regarding their efficacy in reducing HbA1c levels in these settings remains limited.

Aim: This study aimed to evaluate the efficacy of community-based interventions in improving HbA1c levels among patients with T2DM in developing countries.

Methods: A systematic review and meta-analysis were performed following PRISMA guidelines. A comprehensive literature search was conducted in PubMed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Ovid-Medline, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases for full-text randomized controlled trials (RCTs) published between 2015 and 2024. Studies conducted in developing countries focusing on community-based interventions targeting HbA1c outcomes were included. Quality appraisal was conducted using the Joanna Briggs Institute (JBI) critical appraisal tools. Statistical analysis employed a random-effects model to calculate the pooled mean difference (MD) with 95% confidence intervals (CI). Heterogeneity was assessed using the I² statistic. Potential publication bias was assessed using Egger's test, the Trim-and-Fill method, and a funnel plot.

Results: Twenty RCTs involving 4914 participants across developing countries were included. CBIs significantly reduced HbA1c levels compared to usual care, with a pooled MD of -0.54 (95% CI = -0.71, -0.36; P < .00001; I² = 92%). Subgroup analysis showed that education-focused interventions (MD = -0.67; 95% CI = -1.02, -0.31) and physical activity-focused interventions (MD = -0.67; 95% CI = -1.14, -0.20) were the most effective. Analysis by income level revealed no significant differences in efficacy between lower-middle-income and upper-middle-income countries (P = .29). The greatest HbA1c reduction was observed during the 0- to 3-month measurement period (MD = -0.56; 95% CI = -0.90, -0.23).

Conclusion: CBIs are an effective strategy for reducing HbA1c levels among patients with T2DM in developing countries, with significant benefits across diverse economic contexts and intervention models. These findings highlight the adaptability and scalability of CBIs, underscoring their potential to enhance diabetes management in resource-limited settings.

Keywords: HbA1c; community-based interventions; developing countries; glycemic control; type 2 diabetes mellitus.

Figure 1.

PRISMA flow diagram of study selection process.

Figure 2.

Efficacy of CBIs versus usual care.

Figure 3.

Sensitivity analysis of the efficacy of CBIs versus usual care.

Figure 4.

Funnel plot with trim-and-fill adjustments.

Figure 5.

Risk of bias assessment visualization.