Primary care screening for individuals with impaired glucose metabolism with focus on impaired glucose tolerance

•Three questions about heredity, BMI and hypertension are predictive for IGT.•These questions used in an advertisement recruits individuals prone to perform lifestyle changes.•Using HbA1c with a cut-off of ≥42 mmol/mol for screening leaves most individuals with prediabetes undetected.

AimTo evaluate the utility of three short questions (the Skövde Form) combined with a random plasma glucose, and HbA1c as alternative tools for detection of individuals with impaired glucose metabolism (IGM), and particularly impaired glucose tolerance (IGT).MethodsThree questions concerning BMI ≥ 25 kg/m2, heredity for type 2 diabetes, and known hypertension were asked in a random population of 573 individuals. All with two positive answers or one positive answer and a random plasma glucose >7.2 mmol/l were invited for an oral glucose tolerance test and an HbA1c examination. FINDRISC was completed for comparison.ResultsThe positive predictive value (PPV) for IGM, using the Skövde Form, was 31% while sensitivity and specificity were 59% and 73%, respectively. Corresponding values for IGT were 11%, 50% and 69%. Using HbA1c ≥ 42 mmol/mol, the PPV for IGM was 64% while sensitivity and specificity were 28% and 97%, respectively. The corresponding values for IGT were 15%, 16% and 94%.ConclusionThe Skövde Form combined with a random plasma glucose may be used as an alternative tool for detection of individuals with IGM and IGT in particular. HbA1c may be used to identify individuals with type 2 diabetes but fails to detect most individuals with prediabetes.