Use of caffeinated energy drinks among secondary school students in Ontario: prevalence and correlates of using energy drinks and mixing with alcohol.
Reid, Jessica L. ; Hammond, David ; McCrory, Cassondra 等
Caffeinated energy drinks (CEDs) are one of the fastest-growing
segments of the beverage industry. Energy drinks typically contain
caffeine levels ranging from 70 to 180 mg, as well as other ingredients,
including vitamins, herbs, and stimulants such as taurine, ginseng,
guarana, green tea, L-carnitine and yerba mate. (1-3) Sales and
consumption of CEDs have increased dramatically in recent years,
particularly among young people. (3-5) Evidence from a European study
conducted in 2012 and including 16 countries found that 68% of
adolescents had consumed energy drinks in the previous year, as compared
with 30% of adults and 18% of children. (6) Few published studies exist
on energy drink consumption among Canadian youth. However, a 2012 survey
in the Atlantic provinces found that 62% of students in grades 7 to 12
reported CED use at least once in the previous year, (7) and in New
Brunswick 8% of students aged 11 to 19 had used CEDs more than twice a
month. (8) Findings from the 2013 Ontario Student Drug Use and Health
Survey indicated that among students in grade 7 to 12, 40% reported past
year use of CEDs, and prevalence increased with grade, to 50% in grade
12. (9)
The increasing popularity of energy drinks has raised concerns
about the potential health effects of elevated caffeine consumption
among children and youth. (10) Health Canada currently suggests that
adolescents limit caffeine consumption to 2.5 mg/kg per day. (11)
Excessive caffeine consumption among youth can lead to side effects such
as irritability, nervousness, anxiety, dizziness, dehydration,
gastrointestinal disturbances, insomnia and sleep disorders. (2,4,12,13)
High caffeine consumption may also lead to more serious side effects,
such as detrimental effects on bone mineralization, arrhythmia,
tachycardia, seizures, haemorrhage, hallucinations and even death in
rare cases. (2, 12) In the US, an estimated 11% of emergency room visits
linked with energy drink consumption involved youth aged 12 to 17, and
75% of those visits involved only energy drinks. (14)
The use of alcohol mixed with energy drinks (AmEDs) is an
increasingly common practice among youth and young adults. (15, 16)
AmEDs can be found in different forms, including premixed alcoholic
energy drinks or drinks mixed by consumers or bartenders. Reasons for
consuming AmEDs include "partying longer", consistent with
themes portrayed in marketing for CEDs and pre-mixed AmEDs. (17) Alcohol
consumption tends to be greater when combined with energy drinks, (18)
which can produce feelings of increased alertness and energy. (15, 19,
20) Consumption of AmEDs has been associated with binge drinking and a
range of risk behaviours, including driving while intoxicated, alcohol
dependence, increased risk of physical injury and personal harms (such
as being taken advantage of sexually). (16, 21, 22)
A high prevalence of drinking AmEDs among college-age and
post-secondary students has been reported, with some studies indicating
rates above 50%. (13, 20, 21, 23, 24) Recent studies of Canadian
university students have found that 76% had ever consumed AmEDs (24) and
one quarter of past-month alcohol drinkers had consumed AmEDs in that
time. (20) Few studies have assessed AmED use in younger age groups. A
national survey conducted in 2010 found that 5% of youth aged 15 to 17
who had reported using alcohol in the previous 30 days also reported
using AmEDs. (25) Findings from the 2012-13 Youth Smoking Survey (YSS),
another nationally representative survey of students in grades 7 to 12,
indicated that close to a quarter of students reported AmED use in the
preceding year. (26)
The current study sought to examine the prevalence of energy drink
consumption and use of energy drinks with alcohol among a large sample
of secondary students in Ontario, as well as differences in use by
socio-demographic and behavioural characteristics. Existing Canadian
studies on CED use have primarily examined "past year" or
"past month" use, whereas the current study assessed both
"any usual weekly" and weekly frequency of use. The current
study also examined use of AmEDs, which has been associated with
increased risk behaviour and negative outcomes from CED use in studies
conducted outside of Canada, (27) as well as the association of AmEDs
with binge drinking, for which there is limited Canadian evidence. (22)
METHODS
COMPASS is a prospective cohort study designed to collect
longitudinal data from a sample of grade 9-12 secondary school students
in Ontario and Alberta. (28) The current paper reports findings from the
Year 1 data collection that was conducted in 43 Ontario secondary
schools during the 2012/2013 school year. A full description of the
design and methods of the COMPASS study is available elsewhere (28) and
online at www.compass.uwaterloo.ca.
Participants and recruitment
Ontario school boards and schools were purposefully selected. All
English-speaking school boards that had secondary schools operating in a
standard school/classroom setting with grades 9 through 12 and at least
100 students per grade, and that permitted the use of active-information
passive-consent parental permission protocols, were determined eligible
and were approached for participation (n = 40;17 were recruited). A
total of 88 eligible schools in those boards, plus an additional 23
private schools, were approached. Of these, 49 schools (44%) were
recruited for the study, although 6 did not complete data collection.
Parents/guardians of eligible students were mailed information
letters and asked to contact the COMPASS coordinator using the toll-free
phone number or e-mail address provided in the letter if they did not
want their child to participate; all other students were deemed eligible
and could decline to participate at any time. The COMPASS study was
reviewed by and received ethics clearance from the University of
Waterloo Office of Research Ethics and appropriate school board review
panels.
A final sample of 43 Ontario secondary schools, with a total of
30,147 students enrolled, participated in the Year 1 survey. Overall,
80.2% of eligible students (n = 24,173) completed the student
questionnaire. Non-response resulted from absenteeism on the survey date
(18.8%), student refusal (0.1%) and parental refusal (0.9%). An
additional 563 students were deleted from the sample because of missing
data for grade, age, sex, or energy drink use, resulting in a final
sample of 23,610 respondents.
Measures
The student-level questionnaire for COMPASS, designed for
self-completion during class time, assesses multiple behavioural domains
(e.g., alcohol use, tobacco use, obesity, physical activity, eating
behaviour), as well as correlates and demographic characteristics. The
measures were based on existing national standards or surveillance tools
where possible; questionnaire details and psychometric properties for
some measures are available elsewhere. (28-30)
Energy Drink Use
Students were asked, "In a usual school week (Monday to
Friday), on how many days do you do the following? ... Drink high-energy
drinks (Red Bull, Monster, Rock Star, etc.) (none, 1 day, 2 days, 3
days, 4 days, 5 days)." The same question was repeated for a
"usual weekend (Saturday and Sunday)". Responses to the usual
week and weekend questions were added to get weekly frequency of energy
drink use (range: 0-7 days) and recoded into any weekly energy drink use
(0 = no days; 1 = 1-7 days). 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.
Alcohol Use
Current alcohol use was assessed as it is in the national YSS
survey by asking, "In the last 12 months, how often did you have a
drink of alcohol that was more than just a sip?" Participants were
defined as non-users if they reported "I have never drunk
alcohol", "I did not drink alcohol in the last 12 months"
or "I have only had a sip of alcohol". Alcohol users were
defined as those who reported any frequency of drinking more than a sip
in the previous 12 months. Binge drinking was assessed by asking:
"In the last 12 months, how often did you have 5 drinks of alcohol
or more on one occasion?" Responses were coded as 0 = none ("I
have never done this", "I did not have 5 or more drinks on one
occasion in the last 12 months"); 1 = occasional binge drinker
("Less than once a month"); 2 = monthly ("Once a
month", "2 or 3 times a month"); or 3 = weekly or more
("Once a week", "2 to 5 times a week", "Daily
or almost daily"). The two alcohol measures were combined to form
intensity of alcohol use. 0 = no drinking; 1 = alcohol use, no binge
drinking; 2 = alcohol use, occasional binge drinking; 3 = alcohol use,
monthly binge drinking; or 4 = alcohol use, weekly binge drinking.
Socio-demographic Variables
Individual-level socio-demographic variables were age ("13
years or younger" to "18 years or older"), sex and race
(recoded into 1 = White only, non-Aboriginal, 2 = Black only,
non-Aboriginal, 3 = Asian only, non-Aboriginal, 4 = Off-reserve
Aboriginal, 5 = Hispanic only, non-Aboriginal, 6 = Mixed/other,
non-Aboriginal/Not stated). Previous research suggests racial
inequalities in a number of health behaviours, including a higher
prevalence of risk behaviours associated with energy drink use among
visible minorities. (7, 31) Energy drink consumption has also been shown
to vary by age and sex. (7, 9) Grade was not included in the analysis
because of a high correlation (0.91) with age.
Previous evidence suggests that energy drink consumption can
account for a significant proportion of caloric intake: a national
survey of US students in grades 9 to 12 found that energy drinks
represented almost 9% of sugar-sweetened beverage consumption. (32) Body
mass index (BMI) was calculated from self-reported height and weight,
and coded into four categories (underweight, healthy weight, overweight,
obese) using age- and sex-specific cut-offs based on World Health
Organization reference values. (33) Further, anecdotal evidence suggests
that energy drinks may be used to increase or maintain energy levels
while dieting, so weight-related efforts were explored. Weight-related
efforts were assessed with the question, "Which of the following
are you trying to do about your weight? Lose weight, Gain weight, Stay
the same weight, I am not trying to do anything about my weight".
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).
Statistical analyses
Analyses were conducted in 2013 and 2014 using SAS version 9.3.
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. Covariates were age, sex, race, spending money, BMI,
weight-related efforts and intensity of alcohol use. The analysis of
AmED use in past year included only respondents who had used alcohol in
the previous 12 months, and intensity of alcohol use was replaced with
binge drinking. Models accounted for students clustered within schools
by including a random intercept at the school level. For covariates
significantly associated with the outcome, all pair-wise comparisons
between levels were estimated using Bonferroni correction for multiple
comparisons. To test for variation by sex, two-way interactions between
sex and the other covariates were tested by adding the interaction terms
one at a time to the models. Students were excluded from models on a
case-wise basis if data were missing for the outcome or covariates.
Statistical significance was set at a = 0.01 due to the large sample
size.
RESULTS
Sample
Table 1 shows the socio-demographic and behavioural characteristics
of the 23,610 respondents in the current study.
Use of energy drinks
Overall, 18.2% of the sample reported "usually" consuming
energy drinks at least one day a week: 6.5% one day, 4.8% two days, 2.4%
three days, 1.5% four days, 1.2% five days, 0.7% six days, and 1.1%
seven days. Table 2 shows the proportion of students reporting any usual
use of energy drinks by socio-demographic and behavioural
characteristics.
Any Energy Drink Use
In the GLMM for any energy drink use, all covariates were
significantly associated with the outcome: age ([F.sub.(1, 22, 779)] =
102.6, p < 0.0001), sex ([F.sub.(1, 22,779)] = 298.0, p < 0.0001),
race ([F.sub.(5, 22,779)] = 14.8, p < 0.0001), money ([F.sub.(4, 22,
779)] = 12.6, p < 0.0001), BMI ([F.sub.(4, 22, 779)] = 31.0, p <
0.0001), weight-related efforts ([F.sub.(3, 22, 779)] = 4.5, p = 0.004)
and intensity of alcohol use ([F.sub.(4, 22, 779)] = 237.7, p <
0.0001). Table 3 presents all pairwise comparisons between levels of the
covariates. The odds of using energy drinks were significantly greater
in the following socio-demographic groups: males (vs. females);
off-reserve Aboriginal students (vs. "White, non-Aboriginal",
'Asian" or "Mixed/other, non-Aboriginal/Not
stated");students reporting some spending money ($1-20, $21-100,
>$100) compared with reporting $0, and reporting >$100 compared
with $21-100 or not stated. In addition, students with a
"healthy" BMI were less likely to use energy drinks than those
who were underweight, obese or not stated; overweight students were less
likely to use than underweight or not stated. Students who reported
trying to lose weight were more likely to use than those not trying to
do anything about their weight. Intensity of alcohol use was strongly
associated with energy drink use: students reporting any level of
alcohol use were more likely to use than those who did not drink at all,
and the odds increased with increasing intensity of alcohol use.
When two-way interactions between sex and the other covariates were
tested (individually) in the model for any use of energy drinks, several
interactions were significant: sex with age ([F.sub.(1, 22,778)] = 14.4,
p = 0.0001), spending money ([F.sub.(4, 22,775)] = 4.2, p = 0.002) and
weight efforts ([F.sub.(3, 22,776)] = 9.3, p < 0.0001), and the
interaction of sex and race was of borderline significance ([F.sub.(5,
22,774)] = 2.9, p = 0.012). While any use of CEDs increased consistently
with age among males, a contrasting pattern was observed among females:
use was highest among the youngest students and decreased with age up
until age 17; those aged 18 and older also had high use. Although the
same general pattern of increasing CED use by amount of spending money
was observed for both males and females, differences were more
pronounced and significant only among males. There was little difference
in CED use by weight-related efforts among males, but a difference was
observed among females, with particularly high use among those trying to
gain weight. Rates of CED use among males were around twice those of
females in most racial/ethnic groups, except among Aboriginal and Black
students, among whom females' use was higher (closer to
males'). For all estimates of CED use by sex and other covariates,
see Supplementary Table.
Frequency of Energy Drink Use
In the GLMM for usual weekly frequency of energy drink use, all
covariates were significantly associated with the outcome: age
([F.sub.(1, 22, 779)] = 245.1, p < 0.0001), sex ([F.sub.(1, 22, 779)]
= 693.2, p < 0.0001), race ([F.sub.(5, 22, 779)] = 49.0, p <
0.0001), money ([F.sub.(4, 22, 779)] = 43.2, p < 0.0001), BMI
([F.sub.(4, 22, 779)] = 110.6, p < 0.0001), weight-related efforts
([F.sub.(3, 22, 779)] = 10.6, p < 0.0001) and intensity of alcohol
use ([F.sub.(4, 22, 779)] = 706.9, p < 0.0001). The socio-demographic
patterns for pairwise comparisons (Table 3) were similar to those for
any energy drink use, with few exceptions. In general, the differences
were that estimates of similar magnitude were significant when the more
nuanced frequency variable was used, rather than the dichotomous
"any use" outcome. In particular, a number of race comparisons
were significant when the frequency outcome was used: Black and
Aboriginal students used more energy drinks than other racial/ethnic
groups. The two-way interactions of sex with age ([F.sub.(1, 22, 778)] =
10.0, p = 0.002), race ([F.sub.(5, 22, 774)] = 8.0, p [less than or
equal to] 0.0001), spending money (F(4, 22,775) = 3.8, p = 0.005),
weight efforts ([F.sub.(3, 22, 776)] = 37.5, p [less than or equal to]
0.0001) and intensity of alcohol use ([F.sub.(4, 22,775)] = 29.6, p
[less than or equal to] 0.0001) were significant, with patterns similar
to those discussed above for the "any use" outcome. The
interaction of sex with intensity of alcohol use indicated that males
used CEDs more frequently than females at all levels of alcohol use,
although the magnitude of this sex difference narrowed from around
double for occasional or non-drinkers to more comparable levels for
students who reported binge drinking at least weekly.
Use of Alcohol Mixed With Energy Drinks
Overall, 17.3% of the sample (n = 4,016) reported using alcohol
mixed with energy drinks in the previous 12 months; 71.6% (n = 16,892)
reported "never" doing this, 6.4% (n = 1,502) reported that
they "did not do this in the last 12 months", and 3.7% (n =
871) said "I do not know" (a further 329 had no response and
were excluded from further analysis). 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. Table 2 shows the proportion of
past-year alcohol users who reported any use of AmEDs in the previous
year, by socio-demographic and behavioural characteristics.
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.
White students were less likely to use AmED than those who
identified as "Black, non-Aboriginal" (odds ratio [OR] = 0.72,
99% confidence interval [CI]: 0.53-0.98), 'Asian,
non-Aboriginal" (OR = 0.69, 99% CI: 0.51-0.93) or
"Mixed/other, non-Aboriginal/Not stated" (OR = 0.81, 99% CI:
0.67-0.98), but these differences were not significant once all 15
possible pairwise comparisons had been adjusted for. Students reporting
having more than $100 per week in spending money were more likely to use
AmED than those reporting $1-20 (adjusted OR = 1.26, 99% CI: 1.02-1.57).
Binge drinking had the strongest association with using AmED: students
reporting less than monthly (adjusted OR = 2.63, 99% CI: 2.11-3.27),
monthly (adjusted OR = 5.90, 99% CI: 4.78-7.29) or weekly (adjusted OR =
14.73, 99% CI 11.40-19.05) binge drinking were more likely to use AmED
than those who did not binge drink. In addition, monthly (adjusted OR =
2.25, 99% CI: 1.91-2.64) and weekly (adjusted OR = 5.61, 99% CI:
4.51-6.97) binge drinkers were more likely to use AmED than less than
monthly binge drinkers, and weekly binge drinkers were more likely to
use AmED than monthly binge drinkers (adjusted OR = 2.50, 99% CI:
2.04-3.06).
Two-way interactions between sex and the other covariates were
tested, but none were significant, indicating that the relationships
between AmED use and the covariates were consistent across sexes.
DISCUSSION
The current study indicates that nearly one in five Ontario
secondary school students participating in COMPASS reported consuming
energy drinks at least once a week. Of those reporting use, the majority
consumed energy drinks on one or two days a week, although 1 in 10
reported use on 6 or 7 days a week. Relatively little historical data
exist in Canada with which to compare the current estimates. A recent
survey of Ontario students in grades 7 to 12 reported past-year use of
energy drinks at 40%. (9) Although the weekly use rates reported in the
current study are difficult to compare with past year estimates, these
studies are consistent in demonstrating a very high prevalence of use
among young people in Ontario.
Weekly use of energy drinks in the current study was much higher
among males, with nearly twice the proportion of male students reporting
use in the previous week compared with females. This is consistent with
previous research (4, 7, 9) and fits with popular approaches to
marketing energy drinks, which prominently feature themes of masculinity
and risk-taking. (31) Among males, energy drink use increased with age,
while the opposite pattern was observed among females. Other Canadian
and US studies have also found higher use among younger adolescents. (7,
27)
Energy drink use was particularly high among off-reserve Aboriginal
respondents, consistent with previous research indicating markedly
higher prevalence of alcohol and energy drink consumption (22) and risky
health behaviour among off-reserve Aboriginal peoples in Canada. (34,
35) The findings also suggest intriguing associations between energy
drink consumption and diet. Students who were underweight, obese or
overweight were more likely to report consuming energy drinks than
students with healthy weights, as determined by BMI. Similarly, students
who reported trying to lose weight were more likely to use than those
not trying to do anything about their weight.
The current study adds to evidence demonstrating a strong
association between alcohol and energy drink use among youth. Students
reporting any level of alcohol use were more likely to consume energy
drinks, and the odds of consumption increased with greater intensity of
alcohol use. This is consistent with previous research involving young
people in other countries, which has identified strong relationships
between alcohol consumption and/or binge drinking and energy drink
consumption. (6, 36-38)
In addition, binge drinking was the strongest predictor of using
alcohol mixed with energy drinks: more than 60% of youth who reported
binge drinking in the previous week also reported consuming AmEDs. The
current study is among the first in Canada to examine binge drinking and
AmEDs, and extends previous Canadian data indicating an increase in AmED
consumption among youth who have ever tried alcohol. (22) The current
study did not assess the potential negative consequences associated with
alcohol use or AmEDs; however, previous studies have identified a range
of health risks associated with consuming AmEDs among young adults.
(20-22) The consequences of alcohol and energy drink use among youth
should be a priority for future research.
Limitations
The current study has several limitations common to survey
research. First, the study relies on self-reports of energy drink and
alcohol use. Although the survey included concrete examples of energy
drinks ("Red Bull, Monster, Rock Star, etc."), it is
nevertheless possible that some respondents may have over-reported as a
result of confusion with other beverage categories, such as sports
drinks. Although respondents were reassured that survey responses would
be anonymous, the self-reported nature of the data may have
underestimated actual levels of energy drink and alcohol consumption. In
some cases, survey responses yielded conflicting data. For example,
preliminary analyses identified 262 students who reported not having had
more than a sip of alcohol in the previous 12 months but also reported
having used alcohol mixed with an energy drink. 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. In addition, the current survey
did not include a probability-based sample of Ontario schools. However,
it included a large number of schools and students, and had a robust
response rate within participating schools. Finally, the data reported
here are cross-sectional in nature, which limits any causal inferences.
Given that COMPASS data are collected longitudinally, future research
may examine the temporal nature of the associations identified.
CONCLUSIONS
The current study highlights the increasing use of energy drinks
among youth. Given the potential health effects of excessive caffeine
consumption among youth, future studies should assess the quantity of
energy drink consumption in addition to frequency of use. There is also
a need to examine the contexts in which energy drinks are used. Most
importantly, the findings underscore the strong association between
energy drinks and binge drinking among under-age youth. Collectively,
these findings highlight the importance of evaluating existing energy
drink policies with respect to consumption among youth.
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Received: July 14, 2014
Accepted: January 11, 2015
Jessica L. Reid, MSc [1], David Hammond, PhD [2], Cassondra
McCrory, BSc [2], Joel A. Dubin, PhD [3], Scott T. Leatherdale, PhD [2]
Author Affiliations
[1.] Propel Centre for Population Health Impact, University of
Waterloo, Waterloo, ON
[2.] School of Public Health & Health Systems, University of
Waterloo, Waterloo, ON
[3.] Department of Statistics & Actuarial Science, University
of Waterloo, Waterloo, ON
Correspondence: David Hammond, School of Public Health & Health
Systems, University of Waterloo, 200 University Ave West, Waterloo, ON
N2L 3G1, Tel: [telephone] 519-888-4567, ext. 36462, E-mail:
dhammond@uwaterloo.ca
Acknowledgements: The COMPASS study was supported by a bridge grant
from the Canadian Institutes of Health Research (CIHR) Institute of
Nutrition, Metabolism and Diabetes through the
"Obesity--Interventions to Prevent or Treat" priority funding
awards (OOP-110788; grant awarded to Scott Leatherdale) and an operating
grant from the CIHR Institute of Population and Public Health
(MOP-114875; grant awarded to Scott Leatherdale). Additional support was
provided to David Hammond by a CIHR New Investigator Award and a
Canadian Cancer Society Research Institute Junior Investigator Award.
Conflict of Interest: None to declare.
Table 1. Characteristics of the sample of grade 9-12 students
in Year 1 of COMPASS (Ontario), 2012/13
(n = 23,610)
Characteristic % (n)
Mean age (SD) 15.66 (1.25)
Grade
Grade 9 26.2% (6196)
Grade 10 25.7% (6073)
Grade 11 24.5% (5780)
Grade 12 23.6% (5561)
Sex
Female 49.8% (11,769)
Male 50.2% (11,841)
Race
White only, non-Aboriginal 71.4% (16,849)
Black only, non-Aboriginal 4.4% (1040)
Asian only, non-Aboriginal 5.9% (1381)
Off-reserve Aboriginal 5.3% (1257)
Hispanic only, non-Aboriginal 2.3% (536)
Mixed/other, non-Aboriginal/Not stated 10.8% (2547)
Spending money (weekly)
$0 15.7% (3699)
$1-20 30.5% (7203)
$21-100 27.0% (6371)
>$100 14.1% (3321)
Not stated 12.9% (3037)
Body mass index category
Underweight 1.4% (338)
Healthy weight 57.1% (13,498)
Overweight 13.9% (3277)
Obese 6.3% (1478)
Not stated 21.3% (5040)
Weight-related efforts
Lose weight 42.1% (9860)
Gain weight 18.6% (4350)
Stay the same weight 18.4% (4305)
Not trying to do anything 20.9% (4905)
Alcohol use (past 12-month frequency)
None 44.3% (10,237)
Occasional (<once/month) 19.7% (4545)
Monthly (1-3 times/month) 24.6% (5688)
Weekly or more ([greater than 11.4% (2620)
or equal to] once/week)
Binge drinking (past 12-month frequency)
None/Not applicable 60.6% (14,247)
Occasional (<once/month) 16.0% (3750)
Monthly (1-3 times/month) 17.3% (4070)
Weekly or more ([greater than 6.2% (1446)
or equal to] once/week)
Intensity of alcohol use
No alcohol use 44.6% (10,270)
Alcohol use, no binge drinking 15.2% (3513)
Alcohol use with occasional 16.3% (3750)
binge drinking
Alcohol use with monthly 17.7% (4070)
binge drinking
Alcohol use with weekly 6.3% (1446)
binge drinking
Table 2. Use of energy drinks among grade 9-12 students
(n = 23,610) and use of alcohol mixed with
energy drinks among current alcohol users
(n = 12,794), by socio-demographic and behavioural
variables, in the Year 1 COMPASS cohort (Ontario),
2012/13
Any CED use Frequency of CED Any AmED
(usual use (days/week), use (past
weekly), % mean (SD) year), %
Age (years)
[less than or 18.1 0.70 (1.82) 10.2
equal to] 13
14 18.3 0.48 (1.25) 9.1
15 17.6 0.43 (1.18) 12.7
16 18.1 0.47 (1.25) 20.5
17 17.5 0.46 (1.25) 24.1
[greater than or 22.1 0.63 (1.50) 26.8
equal to] 18
Sex
Female 12.9 0.32 (1.02) 26.7
Male 23.4 0.63 (1.44) 31.3
Race
White only, 17.4 0.44 (1.19) 27.7
non-Aboriginal
Black only, non- 21.6 0.66 (1.59) 37.0
Aboriginal
Asian only, non- 12.2 0.33 (1.10) 30.7
Aboriginal
Off-reserve 30.5 0.87 (1.70) 34.3
Aboriginal
Hispanic only, 19.8 0.51 (1.32) 31.8
non-Aboriginal
Mixed/other, 18.3 0.50 (1.33) 31.9
non-Aboriginal/
Not stated
Body mass index category
Underweight 24.3 0.55 (1.23) 27.7
Healthy weight 15.9 0.40 (1.14) 28.7
Overweight 19.0 0.48 (1.23) 29.7
Obese 24.4 0.64 (1.46) 28.4
Not stated 21.4 0.61 (1.48) 29.5
Weight-related efforts
Trying to lose 17.4 0.44 (1.20) 28.7
weight
Trying to gain 23.5 0.65 (1.51) 33.3
weight
Trying to maintain 16.9 0.43 (1.18) 25.7
weight
Not doing 15.9 0.41 (1.17) 27.7
anything
Spending money (weekly)
$0 13.2 0.33 (1.08) 23.6
$1-20 17.1 0.42 (1.17) 24.3
$21-100 19.5 0.49 (1.25) 30.1
> $100 25.3 0.75 (1.61) 35.9
Not stated 16.0 0.43 (1.23) 29.3
Intensity of alcohol use
No alcohol use 11.4 0.28 (0.99) --
Alcohol use, no 15.2 0.36 (1.07) 10.0
binge drinking
Alcohol use with 17.0 0.39 (1.09) 22.5
occasional
binge drinking
Alcohol use with 28.3 0.72 (1.47) 39.3
monthly binge
drinking
Alcohol use with 42.5 1.41 (2.15) 62.7
weekly binge
drinking
CED, caffeinated energy drink; AmED, alcohol mixed with energy
drink.
Table 3. Estimates for all pair/wise comparisons from the models
* for any energy drink use and frequency of energy drink use
among grade 9/12 students in Year 1 of COMPASS (Ontario), 2012/
13 (n = 22,844)
Any energy drink use
Variable Odds 99% CI Adjusted
ratio ([dagger]) p value
Age ([dagger])
Sex 0.85# (0.81-0.88)# < 0.0001#
([double
dagger])
Male vs. female 2.10# (1.88-2.35)# < 0.0001#
Race
Black, non-Aboriginal 1.33 (0.97-1.81) 0.03
(NA) vs. White, NA
Asian, NA vs. White, NA 0.92 (0.67-1.27) 1.00
Aboriginal vs. White, NA 1.80# (1.40-2.31)# < 0.0001#
Hispanic, NA vs. 1.17 (0.77-1.76) 1.00
White, NA
Mixed/other, NA/Not 1.13 (0.92-1.40) 0.60
stated vs. White, NA
Black, NA vs. Asian, NA 1.43 (0.94-2.18) 0.05
Black, NA vs. Aboriginal 0.74 (0.50-1.09) 0.12
Black, NA vs. Hispanic, NA 1.14 (0.69-1.87) 1.00
Black, NA vs. Mixed/ 1.17 (0.82-1.66) 1.00
other, NA/Not stated
Aboriginal vs. Asian, NA 1.95# (1.31-2.88)# < 0.0001#
Aboriginal vs. 1.54 (0.96-2.47) 0.03
Hispanic, NA
Aboriginal vs. Mixed/ 1.58# (1.16-2.16)# < 0.0001#
other, NA/Not stated
Asian, NA vs. Hispanic, NA 0.79 (0.48-1.31) 1.00
Asian, NA vs. Mixed/ 0.81 (0.57-1.16) 0.75
other, NA/Not stated
Hispanic, NA vs. Mixed/ 1.03 (0.66-1.60) 1.00
other, NA/Not stated
Spending money
$1-20 vs. $0 1.34# (1.09-1.64)# < 0.0001#
21-100 vs. $0 1.35# (1.09-1.66)# < 0.0001#
> $100 vs. $0 1.62# (1.29-2.05)# < 0.0001#
Not stated vs. $0 1.20 (0.93-1.53) 0.17
$21-100 vs. $1-20 1.00 (0.85-1. 18) 1.00
> $100 vs. $1-20 1.21 (1.00-1.47) 0.01
$1 -20 vs. Not stated 1.12 (0.91-1.38) 0.72
> $100 vs. $21-100 1.21# (1.00-1.45)# 0.009#
$21-100 vs. Not stated 1.13 (0.91-1.39) 0.64
> $100 vs. Not stated 1.36# (1.08-1.71)# 0.0001#
Body mass index category
Underweight vs. Healthy 2.06# (1.30-3.26)# < 0.0001#
Overweight vs. Healthy 1.07 (0.89-1.29) 1.00
Obese vs. Healthy 1.32# (1.03-1.69)# 0.002#
Not stated vs. Healthy 1.60# (1.37-1.87)# < 0.0001#
Underweight vs. 1.93# (1.19-3.12)# < 0.0001#
Overweight
Obese vs. Overweight 1.23 (0.94-1.62) 0.10
Not stated vs. 1.50# (1.22-1.84)# < 0.0001#
Overweight
Not stated vs. Obese 1.22 (0.94-1.57) 0.13
Underweight vs. Not 1.28 (0.80-2.06) 0.80
stated
Underweight vs. Obese 1.56 (0.94-2.60) 0.04
Weight-related efforts
Trying to lose weight 1.21# (1.01-1.43)# 0.007#
vs. Nothing
Trying to gain weight 1.17 (0.97-1.41) 0.04
vs. Nothing
Trying to maintain 1.12 (0.93-1.35) 0.52
weight vs. Nothing
Trying to gain vs. 1.05 (0.87-1.26) 1.00
Maintain weight
Trying to gain vs. 0.97 (0.81-1.16) 1.00
Lose weight
Trying to lose vs. 1.08 (0.91-1.28) 1.00
Maintain weight
Intensity of alcohol use
Alcohol use, no binge 1.60# (1.32-1.94)# < 0.0001#
drinking vs. No alcohol
Occasional binge 1.90# (1.57-2.30)# < 0.0001#
drinking vs. No
alcohol use
Monthly binge drinking 3.55# (2.99-4.23)# < 0.0001#
vs. No alcohol use
Weekly binge drinking 6.45# (5.14-8.09)# < 0.0001#
vs. No alcohol use
Occasional vs. Alcohol 1.19 (0.96-1.48) 0.08
use, no binge drinking
Monthly vs. Alcohol use, 2.22# (1.82-2.72)# < 0.0001#
no binge drinking
Weekly vs. Alcohol use, 4.03# (3.15-5.17)# < 0.0001#
no binge drinking
Monthly vs. Occasional 1.87# (1.54-2.26)# < 0.0001#
binge drinking
Weekly vs. Occasional 3.39# (2.67-4.29)# < 0.0001#
binge drinking
Weekly vs. Monthly 1.81# (1.46-2.26)# < 0.0001#
binge drinking
Frequency of use (days/week)
Variable exp 99% CI Adjusted
(estimate) ([dagger]) p value
Age ([double ([dagger])
dagger])
Sex 0.87# (0.85-0.89)# < 0.0001#
Male vs. female 1.86# (1.75-1.98)# < 0.0001#
Race
Black, non-Aboriginal 1.42# (1.22-1.65)# < 0.0001#
(NA) vs. White, NA
Asian, NA vs. White, NA 1.03 (0.87-1.23) 1.00
Aboriginal vs. White, NA 1.65# (1.46-1.86)# < 0.0001#
Hispanic, NA vs. 1.14 (0.92-1.42) 0.61
White, NA
Mixed/other, NA/Not 1.17# (1.05-1.31)# < 0.0001#
stated vs. White, NA
Black, NA vs. Asian, NA 1.38# (1.11-1.71)# < 0.0001#
Black, NA vs. Aboriginal 0.86 (0.72-1.04) 0.10
Black, NA vs. Hispanic, NA 1.25 (0.96-1.61) 0.05
Black, NA vs. Mixed/ 1.21# (1.02-1.44)# 0.002#
other, NA/Not stated
Aboriginal vs. Asian, NA 1.60# (1.30-1.96)# < 0.0001#
Aboriginal vs. 1.45# (1.13-1.85)# < 0.0001#
Hispanic, NA
Aboriginal vs. Mixed/ 1.41# (1.21-1.64)# < 0.0001#
other, NA/Not stated
Asian, NA vs. Hispanic, NA 0.91 (0.69-1.19) 1.00
Asian, NA vs. Mixed/ 0.88 (0.73-1.07) 0.41
other, NA/Not stated
Hispanic, NA vs. Mixed/ 0.97 (0.77-1.23) 1.00
other, NA/Not stated
Spending money
$1-20 vs. $0 1.23# (1.09-1.38)# < 0.0001#
21-100 vs. $0 1.25# (1.11-1.40)# < 0.0001#
> $100 vs. $0 1.60# (1.41-1.81)# < 0.0001#
Not stated vs. $0 1.22# (1.06-1.39)# < 0.0001#
$21-100 vs. $1-20 1.01 (0.93-1.11) 0.63
> $100 vs. $1-20 1.30# (1.18-1.44)# < 0.0001#
$1 -20 vs. Not stated 1.01 (0.90-1.13) 0.76
> $100 vs. $21-100 1.29# (1.17-1.41)# < 0.0001#
$21-100 vs. Not stated 1.02 (0.91-1.15) 0.50
> $100 vs. Not stated 1.32# (1.18-1.48)# < 0.0001#
Body mass index category
Underweight vs. Healthy 1.54# (1.20-1.97)# < 0.0001#
Overweight vs. Healthy 1.05 (0.95-1.17) 0.85
Obese vs. Healthy 1.29# (1.14-1.47)# < 0.0001#
Not stated vs. Healthy 1.633 (1.51-1.77)# < 0.0001#
Underweight vs. 1.46# (1.12-1.90)# < 0.0001#
Overweight
Obese vs. Overweight 1.22# (1.06-1.41)# < 0.0001#
Not stated vs. 1.55# (1.39-1.73)# < 0.0001#
Overweight
Not stated vs. Obese 1.273 (1.11-1.44)# < 0.0001#
Underweight vs. Not 0.94 (0.73-1.22) 1.00
stated
Underweight vs. Obese 1.19 (0.90-1.57) 0.37
Weight-related efforts
Trying to lose weight 1.13# (1.03-1.24)# 0.003#
vs. Nothing
Trying to gain weight 1.18# (1.07-1.30)# < 0.0001#
vs. Nothing
Trying to maintain 1.08 (0.98-1.20) 0.10
weight vs. Nothing
Trying to gain vs. 1.09 (0.99-1.20) 0.04
Maintain weight
Trying to gain vs. 1.05 (0.96-1.15) 0.68
Lose weight
Trying to lose vs. 1.04 (0.95-1.14) 1.00
Maintain weight
Intensity of alcohol use
Alcohol use, no binge 1.43# (1.27-1.60)# < 0.0001#
drinking vs. No alcohol
Occasional binge 1.58# (1.42-1.77)# < 0.0001#
drinking vs. No
alcohol use
Monthly binge drinking 2.74# (2.50-3.02)# < 0.0001#
vs. No alcohol use
Weekly binge drinking 4.94# (4.45-5.49)# < 0.0001#
vs. No alcohol use
Occasional vs. Alcohol 1.11 (0.98-1.26) 0.07
use, no binge drinking
Monthly vs. Alcohol use, 1.92# (1.72-2.15)# < 0.0001#
no binge drinking
Weekly vs. Alcohol use, 3.46# (3.06-3.92)# < 0.0001#
no binge drinking
Monthly vs. Occasional 1.73# (1.56-1.93)# < 0.0001#
binge drinking
Weekly vs. Occasional 3.12# (2.78-3.50)# < 0.0001#
binge drinking
Weekly vs. Monthly 1.80# (1.63-1.98)# < 0.0001#
binge drinking
Figures in bold indicate statistically significant associations.
* Separate generalized linear mixed-effects models for each
outcome, with covariates grade, sex, race, spending money, body
mass index, weight-related efforts, and intensity of alcohol use;
school included as a random intercept.
([dagger]) Adjusted for multiple comparisons (Bonferroni),
[alpha] = 0.01.
([double dagger]) (exp)estimate represents the difference between
the two groups in the expected count of the number of days per week
of usual energy drink use, controlling for all other variables in
model (e.g., an exp(estimate) of 1.19 for group A vs. group B
would correspond to an expected 19% greater number of days per
week for group A over group B, controlling for all other variables
in the model).
Note: Statistically significant associations are indicated with #.
