摘要：Age is a major variable to be considered in epidemiology. But age of family members is not considered at all or its consideration seems inadequate in studies on assessing the family history of coronary heart disease as a risk factor. In this report the effects resulting from disregarding age of a family member in such studies were estimated. Age-specific prevalence of the past history of coronary heart disease among 17, 926 family members was obtained from the results of a questionnaire survey of 1, 716 high school students. From the analysis of the age-specific prevalence by the logistic regression model, an odds ratio was estimated which indicated a risk ratio resulting from a difference in age. The odds ratio obtained was 1.065 (95% confidence interval: 1.0601.071). This meant that the odds created by age difference depended on (1.065)n, where n was age difference in years. Thus, the effects of disregarding age of family members in assessing the family history of coronary heart disease can be substantial. If the age difference is greater than 5, its effect expressed by odds becomes larger than 1.370. Some measures to control age of family members need to be taken, especially if the age difference of compared families is not small. J Epidemiol. 1995; 5 : 109-112.
