Validity of Self-reported Diabetes Among Kurdish Population; a Large Population-based Study From Iran

Background: The aim was to assess the validity of diabetes self-reporting based on oral anti-diabetic drugs, insulin injection, or high fasting blood sugar (FBS) in a large Kurdish population of Iran. Methods: : We performed a cross-sectional analytical study on 4400 subjects aged 35-70 years of the Dehgolan Prospective Cohort Study (DehPCS). The reference for having diabetes was oral hypoglycemic drug consumption, insulin injection, or high FBS representing diabetes. Self-reported diabetes status was investigated by well-trained interviewers before the identification of diabetes status based on reference criteria. The accuracy and agreement of self-reported diabetes with reference were assessed in the overall population as well as in different sociodemographic and habitual conditions. Results: : Out of 4400 adults, 3996 agreed to participate in this study (participation=90.8%). The diabetes prevalence among the study population was 13.1% based on self-report and 9.7% based on reference. Of the 523 people who reported diabetes, 213 (41.28%) did not have diabetes. We found a good agreement of 92.3% concordance with a kappa value of 65.1% between self-reported diabetes and reference . Self-reported diabetes also guaranteed sensitivity of 78.5%, specificity of 93.9%, positive predictive value of 58.7%, and negative predictive value of 98.0% to identify diabetic participants. Conclusion: Self-reported diabetes is identified as a valid tool that could accurately determine the diabetes prevalence in epidemiological studies on the Kurdish population of Iran.