A Quantitative Evaluation of the Effects of Sex and Age on the Positivity of Family History of Hypertension

Abstract

The purpose of this study was to call attention to a potential bias or misclassification resulting from disregarding sex and age of family members in assessing family history of hypertension. Family history of hypertension was obtained among 23, 803 family members through a questionnaire survey of 2, 316 high school students. From the obtained data sex- and age-specific proportion of a positive history of hypertension was calculated. The effects of sex and age on a positive history was assessed by the logistic regression analysis of the family history. Below age 70 the odds ratios for sex difference were at least 1.24 (p<0.05) and odds ratios for age difference were at least 1.05 (p<0.05). This indicated that below age 70 male members had a positive history at least 1.24 times more frequently than females of the same age, and that a positive history increased by at least (1.05)Y, where y was age difference by year. Above age 70 the odds ratios for sex and age differences were small. A potential bias or misclassification resulting from sex and age difference can be substantial below age 70. Some measures to control for sex and age of family members are required in assessing the family history. J Epidemiol, 1998 ; 8 : 99-105.