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.