Purpose Our objective was to estimate the change in community-based education interventions throughout the world that may effectuate in risk parameters of type II diabetes (T2D), including the diabetes incidence rate, fasting blood glucose, hemoglobin A1C, body mass index, waist circumference, and systolic and diastolic blood pressure. Methods A comprehensive search for globally eligible studies was conducted on PubMed, Embase, ProQuest, CINAHL nursing & allied health source, Cochrane Library, Google Scholar, conference proceedings, and reference lists. Data were extracted using JBI standardized data extraction tool. The primary outcome variables were diabetes incidence rate, fasting blood sugar (FBS), hemoglobin A1c (HbAlc), body mass index (BMI), waist circumference (WC), systolic/diastolic blood pressure (s/d BP). Random-effects meta-analysis and sub-group analyses were conducted. Results Nineteen interventional studies were included in the review, and ten studies were pooled in the meta-analysis (n = 16,106, mean age = 41.5 years). The incidence rate of T2D was reported in three trials, within which the risk of developing T2D was reduced by 54.0% in favor of community-based educational interventions, (RR = 0.54, 95% CI = 0.38–0.75; p < 0.001). In eleven (n = 11,587) and six (n = 6416) studies, the pooled mean differences were − 0.33 (95% CI: − 0.45 to − 0.20, p < 0.0001) and − 0.15 (95% CI: − 0.28 to − 0.03, p < 0.0001) for FBS and HbA1c levels, respectively. Positive significant effects were observed on reducing BMI [pooled mean difference = − 0.47 (95% CI: − 0.66 to − 0.28), I2 = 95.7%, p < 0.0001] and WC [pooled mean difference = − 0.66 (95% CI: − 0.89 to − 0.43), I2 = 97.3%, p < 0.0001]. The use of theoretical frameworks was found to provide a 48.0% change in fasting blood sugar. Conclusions Based on a comprehensive data collection of about 16,106 participants and reasonable analyses, we conclude that educational interventions may reduce diabetes incidence by 54.0%, particularly through reductions in fasting blood glucose, body mass index, and waist circumference. The diabetes risk parameters may favorably improve irrespective of the duration of intervention, at as low as 6 months. The application of theoretical frameworks while designing educational interventions is also encouraged. Systematic review registration PROSPERO CRD42018115877

Background We assessed community-based educational interventions towards primary prevention of type-II diabetes (T2D), but with a focus on theoretical framework and community factors. Methods A comprehensive search for eligible studies was carried out on PubMed, EMBASE, ProQuest, CINAHL nursing & allied health source, Cochrane Library, Google scholar, conference proceedings, and reference lists. Eligibility criteria were 1) quantitative interventional studies with all designs implemented on general populations and/or the participants at-risk for T2DM within communities (community-based interventions), 2) had no pharmacological treatments within the intervention; 3) had any theoretical frameworks based on health education theories/models; 4) published 2000 onwards and in English language. Data was extracted by using JBI standardized data extraction tool. The primary outcome variables were incidence rate of T2DM, fasting blood glucose (FBG), haemoglobin A1c (HbAlc), mean body weight, mean body mass index (BMI), waist circumference (WC), systolic/diastolic blood pressure (s/d BP). Random effects meta-analysis was conducted to pool the results. Sub-group analyses based on age-group, gender, theoretical framework, and duration of follow-up were also performed.Results Nineteen studies were included in the review and ten studies were pooled in the meta-analysis (n = 16106, mean age = 41.52 years). The incidence rate of T2D was reported in 3 trials, within which the risk of developing T2D was reduced by 54% in favour of the community-based educational interventions, (RR =0.54, 95% CI = 0.38- 0.75; p < 0.001). In eleven (n = 11587) and six (n = 6416) studies the pooled mean difference was -0.33 (95% CI -0.45 to -0.20, p<0.0001) and -0.15 (95% CI -0.28 to -0.03, p<0.0001) for FBG and HbA1c levels, respectively. Positive significant effects were observed on reducing BMI [pooled mean difference = -0.47 (95% CI -0.66 to -0.28, I2= 95.7%, p<0.0001] and WC [pooled mean difference =-0.66 (95% CI -0.89 to -0.43, I2=97.3%, p<0.0001]. There was no favourable effect on reducing s/d BP. Also decline in FBG was seen for both genders but particularly men, for both adults and children but particularly children, and irrespective of having or not having a theoretical framework but particularly for those studies with a theoretical framework. Conclusion In the community-based educational interventions with high quality indices, the risk of developing type 2 diabetes may be reduced by half in favour of all other community-based educational interventions. Given the gross lack of reliable community-based educational interventions, there is no doubt on why we lag behind on T2D prevention; especially in low-middle income populations. Nevertheless, the effected interventions are helpful to bring a favourable change in outcome variables, but, with conditions. Interventions with theoretical framework are likely to be more effective towards diabetes prevention.