External national validation of the Leicester Self‐Assessment score for Type 2 diabetes using data from the English Longitudinal Study of Ageing

Aims To validate the Leicester Self‐Assessment score using a representative English dataset for detecting prevalent non‐diabetic hyperglycaemia or undiagnosed Type 2 diabetes (defined as HbA1c ≥6.0%) and for identifying those who may go on to develop Type 2 diabetes within 10 years. Methods Data were taken from the English Longitudinal Study of Ageing, a nationally representative dataset of people aged ≥50 years. The area under the receiver–operator curve and performance metrics for the score at the recommended score threshold (≥16), were calculated for the outcomes of HbA1c ≥42 mmol/mol (6.0%) at baseline and self‐reported Type 2 diabetes within 10 years in those aged 50–75 years at baseline. Results A total of 3203 individuals had a baseline HbA1c measurement, of whom 247 (7.7%) had an HbA1c concentration ≥42 mmol/mol (6.0%). The area under the receiver–operator curve was 69.4% (95% CI 66.0–72.9) for baseline HbA1c ≥42 mmol/mol. A total of 3550 individuals had diabetes status recorded at 10 years, of whom 324 (9.1%) were diagnosed with Type 2 diabetes within this time; the area under the receiver–operator curve for this outcome was 74.9% (95% CI 72.4–77.5). The score threshold of ≥16 had a sensitivity of 89.2% (95% CI 85.3–92.4) and a specificity of 42.3% (95% CI 40.5–44.0) for Type 2 diabetes within 10 years. Conclusions The Leicester Self‐Assessment score is validated for use across England to identify people with non‐diabetic hyperglycaemia or undiagnosed Type 2 diabetes. Those with a high score are at high risk of developing diabetes in the future. What's new? We have externally validated the Leicester Self‐Assessment score for use across England to detect those at high risk of undiagnosed Type 2 diabetes and non‐diabetic hyperglycaemia. Of those found to be at high risk using the Leicester Self‐Assessment score, 89% will go on to have Type 2 diabetes diagnosed within the next 10 years. The Leicester Self‐Assessment score can be reliably used across England either to detect risk of current undiagnosed disease or to identify those at risk of developing diabetes in the future.