Comparing the Diagnostic Accuracy of HbA1c for Pre-Diabetes and Diabetes Between Foreign-Born and Swedish-Born Primary Healthcare Patients
BackgroundThe aim of this study was to compare the diagnostic accuracy of HbA1c in detecting individuals with abnormally elevated blood glucose levels between foreign-born and Swedish-born primary healthcare patients. The secondary aim was to approximate appropriate HbA1c cut off values for the different populations to yield better sensitivity and specificity.MethodsData analysed in this study was collected in the Programme 4D (Four Diagnoses). Patients aged 18-74 years visiting Flemingsberg
... ing Flemingsberg and Jakobsberg healthcare centres between years 2013-2015 were inquired about inclusion in the study. Exclusion criteria included having a diagnosis of diabetes. Screening included HbA1c, OGTT (including fasting plasma glucose) and questionnaires regarding country of birth as well as prediabetes/diabetes risk assessment questionnaires. In order to calculate diagnostic accuracy of HbA1c-testing, subjects with either both OGTT and HbA1c results and both fP-glucose and HbA1c results were included in the calculation. This totalled in 757 out of the 830 patients.ResultsOnly 22 of 623 patients had elevated results on all three tests. For Swedish-born patients an HbA1c cut off of 42 mmol/mol yielded 12.7% sensitivity and the ROC (Receiver Operating Curve) analysis gave an AUC (Area Under Curve) of 0.756 (0.702-0.810 [95% CI]). For foreign-born patients, an HbA1c cut off value of 42 mmol/mol yielded 19.7% sensitivity and the ROC analysis gave an AUC of 0.6975 (0.646-0.749 [95% CI]).ConclusionsThe diagnostic accuracy for HbA1c in detecting prediabetes and diabetes might be better for the Swedish-born than the foreign-born group. For both groups, an HbA1c cut off value of 34 mmol/mol would yield a sensitivity of >70% which can be considered for further investigation. Comparing the AUC for the two groups might indicate greater diagnostic accuracy for the test in the Swedish-born population than the foreign-born population.