Evaluating measures of family history of alcoholism: density versus dichotomy

AIMS: Studies have used myriad measures of family history of alcoholism (FH) making it difficult to compare them directly. Commonly used FH measures partition samples into the well known positive (FH+) and negative (FH-) dichotomy, although quantitative measures of density potentially provide more information. A standard FH measure would facilitate between-study comparisons. The purpose of this study is to evaluate a quantitative FH measure, called Family History Density (FHD), that has theoretical and practical advantages over currently used measures. DESIGN: Logistic regression equations were estimated for FHD and six commonly used FH measures on alcohol dependence diagnosis, and two measures of alcoholism severity (i.e. withdrawal and tolerance). PARTICIPANTS: Subjects recruited for studies (254 men and 97 women) completed a structured clinical assessment. MEASUREMENTS: Alcoholism diagnosis and endorsement of tolerance or withdrawal symptoms were obtained using the alcohol module from the NIMH Diagnostic Interview Schedule III-R (DIS III-R). Family history of alcoholism was coded using the criteria from the Family Informant Schedule and Criteria (FISC). FINDINGS: All FH measures were associated with alcohol dependence diagnosis, development of tolerance and experiencing withdrawal symptoms in men. In women, only FHD and Parent were significantly associated with all three outcomes. CONCLUSIONS: FHD is a good candidate to be a standard FH measure because it is quantitative, based on familial relatedness and capable of accounting for significant variation in alcoholism diagnosis and two indices of alcoholism severity in men and in women.