Interview to study the determinants of hypertension in older adults in Taiwan: a population based cross-sectional survey.

The aim of the study was to assess the association of socioeconomic, anthropometric and lifestyle factors with self-reported hypertension in older adults in Taiwan. The data were part of the "1999 Survey of Health and Living Status of the Elderly in Taiwan". The survey was conducted in-home, face-to-face, by interviews of 4440 men and women, 53 years or older, in a population-based cross-sectional study. The prevalence of self-reported hypertension was 31.1% for men and 38.0% for women. A logistic regression model showed a higher probability of self-reported hypertension for female gender, older age, and greater BMI, and lower probability for increased consumption of leguminous foods. No association was observed with cigarette smoking, alcohol consumption or physical activity. Current cigarette smokers and alcohol-drinkers underreported their hypertension status. Compared to the medically measured hypertension of a sub-sample study of the same cohort, only about 60% of medically-substantiated hypertensive patients self-reported their hypertensive status, indicating that the interview survey underestimated the prevalence of hypertension in this Taiwanese elderly population. The interview survey appears to identify associations of hypertension with age, gender, BMI and some food patterns, but does not recognize the likely associations with the candidate risk factors of physical inactivity, cigarette smoking, alcohol consumption and limited education, at least in this Taiwanese population. Thus caution must be applied where interview alone categorises individual older Taiwanese as hypertensive or not. A survey which has validation or cross-checking questions about the medical diagnosis of hypertension and the likelihood of its memory and appreciation by the patient (such as method, definition, communication with patient, recall and follow-up, lifestyle advice or pharmaco-therapy, presence of cognitive impairment) may clarify the significance of the discrepancy between self-reporting and medical record. In turn, this would allow a more robust evaluation of blood pressure determinants in such populations. Nevertheless, there is a role for community-based surveys that utilise self-reporting in the identification, prioritization and surveillance of putative contributors to hypertension; this is the case where, as in the Taiwanese elderly, it assumes major importance in the burden of disease and premature mortality.