EPIDEMIOLOGIC FEATURES OF FIRST-VISIT OUTPATIENTS IN JAPAN - COMPARISON WITH GENERAL-POPULATION AND VARIATION BY SEX, AGE, AND SEASON

To evaluate the methodological issues in using first-visit outpatients as controls in epidemiological studies, the features of general lifes tyles of non cancer outpatients at Aichi Cancer Center Hospital (ACCH) were compared with those of the general population, and their variati on by sex, age, and season was determined by using a self-administered questionnaire. The study included 1231 subjects randomly selected fro m the Nagoya electoral roll (CRG), and three groups of non-cancer ACCH outpatients living in Nagoya; 800 from the period September to Decemb er 1992 (OPG1), 2326 from January to December 1992 (OPG2), and 12,243 from January 1991 to December 1992 (OPG3). In the younger age group, t he proportion of current smokers was higher in the CRG than in the OPG s. In the older age groups, the proportion of those who consumed fresh vegetables and fruit everyday was higher in the OPGs than in the CRG. For other items, the features of the OPGs were not significantly diff erent from those of the CRG. Among the OPG3, there were differences in the features of general lifestyles between sexes and consumption of s everal food items varied with age. Seasonal variation, however, was on ly observed in the specific food items where supply varied seasonally. It was concluded that, with due consideration of age, sex, and season in the analysis, it is feasible to use non-cancer outpatients as cont rols in epidemiological studies. Copyright (C) 1997 Elsevier Science I nc.