Validity of Self-Reported Diabetes in a Mashhad Population

  Researchers and health specialists are increasingly using self-reports to obtain information on chronic illnesses. This study was conducted to assess the validity of self-reports of diabetes based on a recent field survey in Mashhad.

In this cross-sectional study, we used the results of 2015 census in Mashhad, a population based survey of people over the age of 30 (n =307103), to determine the proportion of self-reported diabetes. The patient records of Sina Electronic Health Record system (SinaEHR®) coded as E11 and E12 approved by doctors were used as a reference. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated with 95% confidence intervals.

The sensitivity, specificity, PLR, NLR, PPV, and NPV of self-reported diabetes was 24.59% (95% CI: 23.97-25.21), 98.04% (95% CI: 97.99-98.09), 12.56% (95% CI: 12.11-13.02), 0.77% (95% CI: 0.76-0.78), 44.77% (95% CI: 43.89-45.67), and 95.27% (95% CI: 95.23-95.31), respectively. The sensitivity of self-reported diabetes was higher in men, Iranian individuals, single subjects, people aged 60 and over, individuals with a BMI of 18.5-25, and those with university education.

Although the sensitivity of self-reported diabetes was poor in this study, its specificity and positive and negative predictive values were good. Furthermore, the sensitivity of self-reported diabetes was higher in men, Iranian individuals, single subjects, people aged 60 and over, individuals with a BMI of 18.5-25, and those with university education. It seems that caution should be exercised in using self-reported data in epidemiological studies.