Because of the limitations of the genetic statistical analysis program, we were unable to simultaneously analyze both continuous and ordinal variables; thus, we collapsed the drinking measures into 4 categories (once individuals who had indicated that they do not use alcohol were removed). An alcoholic drink was defined as “1 bottle of beer, 1 glass of wine, or 1 shot of liquor” across all questions. For drinking frequency, frequency of heavy drinking, and frequency of intoxication, these categories were (1) About 1 to 4 times a year, (2) About once in 2 months, (3) About 1 to 2 times a month, (4) About 1 to 2 times a week. Max Drinks, the Mm-MAST, and RAPI scores were each collapsed into 5 levels using the SAS System’s univariate quintiles procedure, where the first level contains those individuals lowest on problem drinking and the fifth level contains those highest on problem drinking (SAS, 2000–2004).
