These respondents were excluded from the analysis; however, it remains unclear whether this pattern reflects reporting error or indicates that some youth omit reporting AmEDs as alcohol consumption.
Alcohol mixed with energy drink (AmED) use in the past year was assessed using an item consistent with the YSS that asks, "In the last 12 months, have you had alcohol mixed or pre-mixed with an energy drink such as Red Bull, Monster, Rock Star, or another brand?" with responses "I have never done this", "I did not do this in the last 12 months", "Yes" and "I do not know", recoded as 0 = Never/Not in last 12 months/Don't know; 1 = Yes.
Spending money, associated with AmED use in a previous Canadian study, (22) presumably because the higher cost of these drinks may serve as a barrier to some youth, was assessed using the question, "About how much money do you usually get each week to spend on yourself or to save?" with responses recoded as 0 = $0,1 = $1-$20, 2 = $21-$100, 3 = >$100, and 4 = Not stated (Missing/Don't know).
Separate generalized linear mixed-effects models (GLMMs) were fit to examine correlates of each of three outcomes: 1) any weekly energy drink use, 2) weekly frequency of energy drink use and 3) AmED use in past year, specifically, PROC GLIMMIX using Adaptive Gaussian Quadrature was used to estimate a logistic GLMM for outcomes 1 and 3, and a Poisson GLMM for outcome 2.
Of the 55.7% of students (n = 12,843) who reported using alcohol in the previous 12 months, 28.9% reported having used AmED. An additional 262 students (2.6%) who reported not having had more than a sip of alcohol in the previous 12 months also reported having used AmED.
In the GLMM for any energy drink use mixed with alcohol among past 12-month drinkers, of the covariates age, sex, race, money, BMI, weight-related efforts and binge drinking, only race ([F.sub.(5, 12,587)] = 5.1, p = 0.0001), spending money ([F.sub.(4, 12,587)] = 4.0, p = 0.003), and binge drinking ([F.sub.(3, 12,587)] = 436.0, p < 0.0001) were significantly associated with using AmED.