ABSTRACT
This study aimed to investigate the validity of self-reported hypertension and related factors in the Dehgolan Prospective Cohort Study (DehPCS). Data were obtained from 3996 participants aged 35-70 years in the enrolment phase of DehPCS. Self-reported hypertension and sociodemographic factors were collected by well-trained interviewers before hypertension diagnosis based on the reference criteria. The history of anti-hypertensive medication use and/or systolic blood pressure ≥140 (mmHg), or diastolic blood pressure ≥90 (mmHg) were considered as hypertension. Disagreement between self-reported and reference measures was assessed using sensitivity, specificity, positive, and negative predictive values (PPV and NPV), and kappa values. Binary and multinomial logistic regressions were used to investigate the correlates of validity of self-reported hypertension. The hypertension prevalence based on self-reports and the reference criteria was 19.49% and 21.60%, respectively. An acceptable percentage of kappa agreement value of 68.7% and relatively good overall agreement of 89.8% were found. Self-reported hypertension was guaranteed moderate sensitivity of 72.0% and high specificity of 94.5%, as well as the NPV and PPV of 92/7% and 77/9%, respectively. The chances of false-positive and false-negative reporting increased with older age, higher BMI, and a family history of hypertension. Being female, older age, higher BMI, concurrent diabetes, and stronger family ties to hypertension patients significantly increased the chance of reporting true positives relative to true negatives. Although, self-reported hypertension has an acceptable validity and can be used as a valid tool for screening epidemiological studies, it needs to be investigated because its validity is affected by age, gender, family history of hypertension, and other socio-demographic characteristics.
