The relative risk of developing type 2 diabetes among individuals with prediabetes compared with individuals with normoglycaemia: Meta‐analysis and meta‐regression

Aims To assess the overall relative risk of diabetes in individuals with prediabetes based on updated diagnostic criteria, as compared with individuals with normoglycaemia; and to identify the study characteristics associated with the heterogeneity between studies. Design Meta‐analysis, meta‐regression. Data sources PubMed, CINAHL, British Nursing Index. Search time frame: December 1998–December 2018. Review Methods The pooled relative risk of developing diabetes among individuals with prediabetes compared with those with normoglycaemia was calculated under a random effects model. Studies reported the natural progression from prediabetes to diabetes were included in this review. Sources of study heterogeneity were examined by a meta‐regression. Results Fifty‐nine eligible studies were systematically identified. The pooled relative risk for diabetes among individuals with prediabetes as compared with normoglycaemia was 5.88 (95% CI: 5.02‐6.89). The annualized incidence rate (per 1,000 person‐year) for diabetes among individuals with prediabetes defined by different criteria varied from 2.20–212.15, with high heterogeneity between studies (I2 = 96.64%, Q test: p