Evaluation of Diabetes Risk Models Applied to the Prediction of Incident Dysglycaemia in African and European Populations.

AIMS: We evaluated overall and sex-specific performance of established diabetes risk models for predicting incident dysglycaemia in African and European populations. MATERIALS AND METHODS: We externally evaluated the African Diabetes Risk model, Finnish Diabetes Risk model, Epidemiological Study on the Insulin Resistance Syndrome model and the personal and clinical Framingham models. Evaluation was performed in three prospective cohorts: the Research on Obesity and Diabetes among African Migrants (RODAM-Pros; migrant and non-migrant Ghanaians; n = 1607), the Middle-aged Soweto cohort (MASC; urban Black South Africans; n = 515) and the Västerbotten Intervention Programme (VIP; Sweden; n = 3044). Dysglycaemia was defined according to American Diabetes Association criteria. Discrimination (c-statistic) and calibration were assessed before and after recalibration. RESULTS: Dysglycaemia developed in 17.7% of RODAM-Pros participants, 35.0% of MASC participants and 27.5% of VIP participants, with median follow-up of 6.7, 6.7 and 9.9 years, respectively. All models demonstrated poor-to-modest discrimination (c-statistic < 0.7). Most models substantially underestimated risk. Recalibration eliminated systematic miscalibration and reduced calibration error to ≤ 2.3% in RODAM-Pros and VIP and ≤ 3.4% in MASC. Performance varied by sex and cohort. CONCLUSIONS: Existing diabetes risk prediction models can be applied to predict incident dysglycaemia in both Sub-Saharan African and European populations, but only after recalibration to local risk levels.