A BRIEF ORIGINAL CONTRIBUTION Adult Female Twins ' Recall of Childhood Social Class and Father's Education: A Validation Study for Public Health Research

To assess recall of childhood socioeconomic position for public health research, the authors conducted a cross-sectional study of 352 adult women twin pairs enrolled in Examination II of the Kaiser Permanente Women Twins Study carried out in 1989-1990 in Oakland, California. Among twin pairs, 91 % (95 % confidence interval (Cl) 89-94%) agreed on their father's educational level and 81 % (95 % Cl 77-85%) on their childhood social class. Recall did not differ by adult socioeconomic position, zygosity, race/ethnicity, or age. Thus, epidemiologic studies can validly use retrospective data on childhood socioeconomic position to study its relation to adult health status. Am J Epidemiol 1998;147:704-8. bias (epidemiology); educational status; health status; life cycle; recall; social class; socioeconomic factors; twin studies Epidemiologists and others are increasingly document-ing that cumulative disadvantage—and privilege— across the lifespan, from childhood to adulthood, may be important determinants of adult health status ( 1-20). Much of this research, except for a few longitu-dinal studies (14, 17) and ecologic analyses (16, 20), has relied on adults ' recall of childhood socioeco-nomic conditions. To our knowledge, however, no studies have examined accuracy of recall of childhood socioeconomic position and whether it differs by adult socioeconomic position. Accordingly, the purpose of our study was to assess recall of childhood social class and father's education for public health studies, using data from a cohort of US adult women twins. MATERIALS AND METHODS Study population Our cross-sectional study was based on a cohort of 704 women twins (352 twin pairs) who participated i