Socio-demographic Correlates of Diabetes Self-reporting Validity: An Adult’s Kurdish Population-based Study

Background: The aim was to assess the validity of self-reported according to the demographic and socio-economic feature in a the Dehgolan Prospective Cohort Study (DehPCS)Methods: We performed a cross-sectional analytical study on 4400 subjects aged 35-70 years of 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 validity criteria of self-reported diabetes were assessed using sensitivity, specificity, positive and negative predictive values. Socio-demographic correlates of self-reported agreement were examined by multinomial logistic regression. Results: 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% with an acceptable 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 and negative predictive value of 58.7% and of 98.0% respectively. Female, higher economic class, higher BMI, and family history of diabetes were increased the chance of false positive. Being male and aging and moderate economic class increased the chance of false positive. Conclusion: Self-reported diabetes is identified as a relatively valid tool that could fairly determine the diabetes prevalence in epidemiological studies. It should be noted that its validity is influenced by some socio-demographic characteristics.