Comparison of self-reports and biomedical measurements on hypertension and diabetes among older adults in China

Background: Researchers interested in the effects of health on various life outcomes often use self-reported health and disease as an indicator of true, underlying health status. However, the validity of reporting is questionable as it relies on the awareness, recall bias and social desirability. Accordingly, biomedical test is generally regarded as a more precise indication of the disease.Methods: Using data from the third wave of China Health and Retirement Longitudinal Study (CHARLS), we selected individuals aged 40-85 years old who participated in both health interview survey and biomedical test. Sensitivity, specificity, false negative reporting and false positive reporting were used as measurements of (dis)agreement or (in)validity, and binary and multinomial logistic regression were used to estimate under-report or over-report of hypertension and diabetes. Results: Self-reported hypertension and diabetes showed low sensitivity (73.24% and 49.21%, respectively) but high specificity (93.61% and 98.05%, respectively). False positive reporting of hypertension and diabetes were 3.97% and 1.67%, while false negative reports were extremely high at 10.14% and 7.38%. Educational attainment, hukou, age and gender affected both group-specific error and overall error with some differences in their magnitude and directions.Conclusion: Self-reported conditions underestimate the disease burden of hypertension and diabetes in China. Adding objective measurements into social survey could improve data accuracy and allow better understanding of socioeconomic inequalities in health. Furthermore, there is an urgent need to provide basic health education and physical examination to citizens, and promote the use of healthcare to lower the incidence and unawareness of disease in China.