The relationship between the resulting categorical volume levels, defined as 1, 2, 3–4, 5–6, 7–9, and 10+ drinks for each of self-reported consumption, the empirical regression, and the Widmark approaches can be seen in Table 3 and Table 4. A weighted Cohen’s κ with weights defined as 1, .8, .6, .4, .2 and 0 was used to estimate agreement between self-reported consumption (VSR) and volume from both the empirical (V^E) and Widmark (V^W) approaches. The self-reported and empirical volume relationship is shown in Table 3 and produces κ = .16 (.02) with a correlation of the two quantities of ρ = .26. The relationship between self-reported and Widmark volume is shown in Table 4 and produces κ = .15 (.02) with ρ = .25. When the sample is restricted to only those who arrive to the ER within 3 hours of the last drink, yielding 822 cases with complete data for which all 3 volume variables could be calculated, the corresponding values were κ = .18 (.02) and κ = .19 (.02).
