The interpretability of family history reports of alcoholism in general community samples: findings in a midwestern U.S. twin birth cohort.

BACKGROUND Although there is a long tradition in alcoholism research of using family history ratings, the interpretability of family history reports of alcoholism from general community samples has yet to be established. METHODS Telephone interview data obtained from a large cohort of female like-sex twins (N = 3,787, median age 22) and their biological parents (N = 2,928, assessed at twins' median age 15) were analyzed to determine agreement between parent self-report, parent ratings of coparent, and twin narrow (alcohol problems) and broad (problem or excessive drinking) ratings of each parent. RESULTS In European ancestry (EA) families, high tetrachoric correlations were observed between twin and cotwin ratings of parental alcohol problems, between twin and parent ratings of coparent alcohol problems using symptom-based and single-item assessments, as well as moderately high correlations between twin and both mother and father self-reports. In African American (AA) families, inter-rater agreement was substantially lower than for EA families, with no cases where father ratings of maternal alcohol problems agreed with either twin ratings or mother self-report, and both cotwin agreement and mother-twin agreement were reduced. Differences between EA and AA families were not explained by differences in years of cohabitation with father or mother's education; however, underreporting of problems by AA parents may have contributed. CONCLUSIONS Results support the use of family history ratings of parental alcoholism in general community surveys for EA families, but suggest that family history assessment in AA families requires improved methods.