Health system interventions for adults with type 2 diabetes in low- and middle-income countries: A systematic review and meta-analysis

Author summary Why was this study done? Approximately 80% of the 463 million adults with type 2 diabetes worldwide live in low- and middle-income countries (LMICs). Evidence-based treatments for diabetes exist, but health systems in LMICs have difficulty meeting diabetes patients' needs. Health system interventions can help address this gap by improving the delivery of diabetes care within health systems. What did the researchers do and find? We conducted a systematic review and meta-analysis of 39 health system interventions aiming to improve outcomes of glycemic (i.e., blood glucose) control, mortality, quality of life, or cost-effectiveness for people with type 2 diabetes in LMICs. We found that health system interventions for type 2 diabetes may be effective in improving glycemic control in LMICs, but few studies were available from rural areas or low- or lower-middle-income countries. Among intervention types, multicomponent clinic-based interventions had the strongest evidence for improving glycemic control. What do these findings mean? Our findings support the scaling up of diabetes health system interventions to improve patients' glycemic control in LMICs. Further research is needed to assess other outcomes beyond glycemic control, especially in rural areas and in low- or lower-middle-income countries. Background Effective health system interventions may help address the disproportionate burden of diabetes in low- and middle-income countries (LMICs). We assessed the impact of health system interventions to improve outcomes for adults with type 2 diabetes in LMICs. Methods and findings We searched Ovid MEDLINE, Cochrane Library, EMBASE, African Index Medicus, LILACS, and Global Index Medicus from inception of each database through February 24, 2020. We included randomized controlled trials (RCTs) of health system interventions targeting adults with type 2 diabetes in LMICs. Eligible studies reported at least 1 of the following outcomes: glycemic change, mortality, quality of life, or cost-effectiveness. We conducted a meta-analysis for the glycemic outcome of hemoglobin A1c (HbA1c). GRADE and Cochrane Effective Practice and Organisation of Care methods were used to assess risk of bias for the glycemic outcome and to prepare a summary of findings table. Of the 12,921 references identified in searches, we included 39 studies in the narrative review of which 19 were cluster RCTs and 20 were individual RCTs. The greatest number of studies were conducted in the East Asia and Pacific region (n = 20) followed by South Asia (n = 7). There were 21,080 total participants enrolled across included studies and 10,060 total participants in the meta-analysis of HbA1c when accounting for the design effect of cluster RCTs. Non-glycemic outcomes of mortality, health-related quality of life, and cost-effectiveness had sparse data availability that precluded quantitative pooling. In the meta-analysis of HbA1c from 35 of the included studies, the mean difference was -0.46% (95% CI -0.60% to -0.31%, I-2 87.8%, p < 0.001) overall, -0.37% (95% CI -0.64% to -0.10%, I-2 60.0%, n = 7, p = 0.020) in multicomponent clinic-based interventions, -0.87% (-1.20% to -0.53%, I-2 91.0%, n = 13, p < 0.001) in pharmacist task-sharing studies, and -0.27% (-0.50% to -0.04%, I-2 64.1%, n = 7, p = 0.010) in trials of diabetes education or support alone. Other types of interventions had few included studies. Eight studies were at low risk of bias for the summary assessment of glycemic control, 15 studies were at unclear risk, and 16 studies were at high risk. The certainty of evidence for glycemic control by subgroup was moderate for multicomponent clinic-based interventions but was low or very low for other intervention types. Limitations include the lack of consensus definitions for health system interventions, differences in the quality of underlying studies, and sparse data availability for non-glycemic outcomes. Conclusions In this meta-analysis, we found that health system interventions for type 2 diabetes may be effective in improving glycemic control in LMICs, but few studies are available from rural areas or low- or lower-middle-income countries. Multicomponent clinic-based interventions had the strongest evidence for glycemic benefit among intervention types. Further research is needed to assess non-glycemic outcomes and to study implementation in rural and low-income settings.