Two approaches were taken with the goal of estimating self-reported volume of consumption from BAC among these 1,953 patients. The first approach was to estimate self-reported number of drinks empirically from the bivariate relationship between BAC and self reported volume using fractional polynomials in Stata (Stata Corp, 2007). The second approach was to use Widmark’s equation (Brick, 2006), defined as: BAC= [(0.01882816× VSR ×C)/(W×G)] − L·H where the constant .01882816 is the concentration of alcohol in blood (g/L), VSR is the self-reported volume of consumption in number of 12 gram drinks, C is the alcohol concentration by volume of the specific beverage type (40% was used for spirits, 12.5% for wine, and 5% for beer), W is the weight of the patient in kg, G is the percentage of water in the body (assumed to be 58% for men and 49% for women), L is the liver clearance rate (assumed to be .017/hour for those reporting a usual quantity of less than 2 drinks/day and .020/hour for reporting 2 or more drinks/day) and H is the number of hours from
