Drinking Plans and Drinking Outcomes: Examining Young Adults' Weekend Drinking Behavior
Transcript of Drinking Plans and Drinking Outcomes: Examining Young Adults' Weekend Drinking Behavior
J. DRUG EDUCATION, Vol. 41(3) 253-270, 2011
DRINKING PLANS AND DRINKING OUTCOMES:
EXAMINING YOUNG ADULTS’ WEEKEND
DRINKING BEHAVIOR*
RYAN S. TRIM, PH.D.
University of California San Diego
JOHN D. CLAPP, PH.D.
MARK B. REED, PH.D.
AUDREY SHILLINGTON, PH.D.
San Diego State University, California
DENNIS THOMBS, PH.D.
University of North Texas, Fort Worth
ABSTRACT
This study examined relationships among drinking intentions, environments,
and outcomes in a random sample of 566 undergraduate college students.
Telephone interviews were conducted with respondents before and after a
single weekend assessing drinking intentions for the coming weekend related
to subsequent drinking behaviors. Latent class analyses found evidence for
four distinct drinking environments distinguished by private/public setting
and presence of few/many intoxicated people. There was evidence that the
drinking environment mediated the relationship between drinking intentions
and heavy episodic drinking in this young adult sample. Future research might
focus on examining person/environment interactions as they relate to heavy
episodic drinking.
*Funding for this study was provided in part by a grant the National Institute on Alcohol
Abuse and Alcoholism to Dr. Clapp (R01 AA01368).
253
� 2011, Baywood Publishing Co., Inc.
doi: 10.2190/DE.41.3.b
http://baywood.com
INTRODUCTION
Despite decades of research and prevention efforts, alcohol misuse among college
students and its attendant problems remains a serious public health concern.
The most recent Monitoring the Future report indicates 85% of all college students
have consumed alcohol at least once in their lifetime, with 40% of college age
drinkers reporting at least one occasion of heavy drinking (five or more drinks in a
single sitting) in the past 2 weeks (Johnston, O’Malley, Bachman, & Schulenberg,
2009). Among the 80,000 alcohol attributable deaths that occur in the United
States each year, about 10,000 occur among people under 25 years of age
(Centers for Disease Control and Prevention [CDC], 2009) and an estimated
1,700 college students die from an alcohol-related cause each year (Hingson,
Zha, & Weitzman, 2009).
The etiology of alcohol misuse among young adults has been conceptual-
ized many ways. Consistent with public health models (e.g., agent-person-
environment) and ecological models, many etiological models include both
psychological factors such as motivations or drinking intentions (Clapp, Lange,
Min, Johnson, Shillington, & Voas, 2003; Lange & Voas, 2001), and environ-
mental factors (Clapp, Min, Shillington, Reed, & Croff, 2008; Clapp, Reed,
Min, Shillington, Croff, Holmes, et al., 2009; O’Mara, Thombs, Wagenaar,
Rossheim, Merves, Wei, et al., 2009). Understanding such person/environment
interactions is necessary to inform prevention planning and policies designed
to regulate harmful drinking and alcohol-related problems. At the drinking
event level, understanding the relationships among person level factors and
environmental characteristics as they relate to heavy drinking represent potential
“leverage points” for prevention efforts (Stokols, 2000).
Recent studies have made advances in what we know about drinking environ-
ments frequented by young adults and how they interact with person-level
variables. Thombs et al. (2009) recently published a field study illustrating that
drinking history, past year alcohol consumption, and age of onset of alcohol
use were related to bar-going behavior, which in turn was related to post-bar
blood alcohol content. Similarly, Clapp and colleagues reported on a series of
field studies that examined both private and public drinking settings (Clapp
et al., 2009; Clapp, Min, et al., 2008) and found that both individual (e.g., intention
to get drunk) and environmental characteristics (e.g., themed drinking events,
temporary bars) contributed to high levels of blood alcohol.
In both the Theory of Reasoned Action (Ajzen & Fishbein, 1980) and the
Theory of Planned Behavior (Ajzen, 1991), behavioral intentions play a sig-
nificant role in the prediction of actual behavior. In the area of college student
drinking, several studies have established an association between intentions to
drink alcohol and alcohol consumption (Collins & Carey, 2007; Hutching, Lac,
& LaBrie, 2008). A similar relationship has also been shown utilizing a sample
of young adult bar patrons (Clapp et al., 2009). An earlier paper by Clapp et al.
254 / TRIM ET AL.
(2003) modeled the relationships among intentions to get drunk, drinking environ-
ment, and drinking outcomes and found that environmental factors such as
the presence of illicit drugs, the playing of drinking games, and perceiving
many people at an event were intoxicated mediated intentions and behaviors.
Additionally, the results of a recent study examining drinking behavior in a sample
of college women showed factors such as injunctive and descriptive norms,
peers approve of drinking and peers drink more heavily, as well as pressures
to drink mediated the relationship between pre-college drinking intentions and
heavy episodic drinking (HED) in college (Testa, Kearns-Bodkin, & Livingston,
2009). The authors concluded intentions to drink among these students might
have influenced the selection of social environments that support and facilitate
heavy drinking (i.e., peers who condone heavy drinking and who drink heavily
themselves).
Despite these advances, relatively little is understood concerning how drinking
intentions relate to the selection of drinking environments, and ultimately drinking
behavior given the limitations of the studies cited above. For example, the study
conducted by Clapp et al. (2003) was limited in that it relied on cross-sectional
data and relatively simplistic indicators of environment and drinking intentions.
These simplistic indicators included dichotomous responses on environmental
characteristics including the presence of food, whether illicit drugs such as
marijuana were available, and the availability of beer or hard alcohol. Moreover,
the generalizability of the results of Testa et al. (2009) is limited given their
sample only included female college students. This study addresses these gaps by
employing pre- and post-drinking measures of specific drinking events, a more
comprehensive measure of drinking intentions, and the inclusion of both male and
female participants. For the initial analyses, classification of a priori groups
that vary on intent to get drunk and self-reported HED provides insight into
the impact of consistency (or lack thereof) of planned behaviors on individual
and environmental characteristics. Specifically, the study examines the following
research questions:
1. Do drinking intentions predict drinking environment characteristics and
does this vary as a function of self-reported drinking?
2. How do demographics, intentions, and heavy drinking relate to different
classes of drinking environments?
3. Do drinking environments mediate the relation between drinking inten-
tions and heavy drinking?
METHODS
Design and Sample
To answer the above research questions we conducted an event-level study
in which drinking intentions were measured prior to specific drinking episodes,
with drinking outcomes being measured a day or two after the same drinking
DRINKING PLANS AND DRINKING OUTCOMES / 255
event. This approach was designed to overcome problems associated with
retrospective surveys (Clapp et al., 2009), including inaccurate attribution of
drinking intentions for a past drinking event (i.e., post-hoc attributions of drinking
intentions to drinking outcomes) and faulty recall due to a long period of time
between drinking event and follow-up assessment. This study was approved by
the San Diego State University Institutional Review Board.
In the spring of 2005, we collected survey data from a random sample of
30 individuals enrolled at a 4-year undergraduate institution each week for a
total of 19 weeks. The sample was generated from university records. Demo-
graphically, the sample was representative of the campus population from which
it was drawn (95% CI, ± 3%); however, the sample did contain more heavy
drinkers than previous studies from this same population (Clapp, Shillington,
& Segars, 2000). Compared to the demographic make-up of the host university,
the sample was very similar with respect to gender (53% female), and the majority
were white, non-Hispanic (62.6%). The mean age of the respondents was 21.0
years (SD = 1.71), and 63% of the sample reported at least one instance of
heavy episodic drinking (5 or more drinks) in the past 2 weeks. The mean age of
undergraduates at the university the year the data were collected was 22.5 years
and males represented 40.1% of the student population that year.
Each week, 25 respondents were interviewed by telephone two times within
a 5-day period. Data were collected on Wednesdays (pre-weekend survey) and
Mondays (post-weekend survey). Respondents were assigned a unique identifica-
tion number and all contact information for the respondents was destroyed after
data collection. To test for the possibility that respondents might alter their
behavior due to the pre-event interview (i.e., reactivity), five respondents were
interviewed on Mondays only and asked about their past weekend drinking. We
compared drinking patterns of these two samples and found no testing effect
related to the pre-weekend survey. A total of 566 matched pre/post interviews
and 146 post-weekend only interviews were completed. The study had a refusal
rate of 20.6%; 79.4% of qualified students contacted agreed to participate.
Only students who provided complete data on drinking intentions, environ-
ments, and drinking outcomes were included in the current study (n = 375; 66% of
total sample). Regarding the targeted weekend of interest, 26% reported drinking
on both Friday and Saturday nights, 48% only drank on Friday night, and 26%
only drank on Saturday night. To avoid confounds due to non-independence of
observations, only data from Friday were used for subjects who reported drinking
on both nights (since Saturday drinking would likely be biased by the level of
Friday drinking for these individuals).
Measures
An original interview schedule was developed for this study. Given the intent of
the study was to further examine the relationships among drinking intentions,
256 / TRIM ET AL.
drinking environments, and drinking behavior, we included a series of questions
measuring contexts of student drinking. Several of these context items originated
from the College Alcohol Risk Assessment Guide (Ryan, Colthurst, & Segars,
1997) and have been refined in our prior work (Clapp et al., 2000, 2003; Clapp,
Min, Shillington, Reed, Lange, & Holmes, 2006; Clapp, Voas, & Segars, 2001).
Clapp et al. (2003) established the predictive validity of several of these original
items in an earlier study.
The pre-drinking event survey included demographic items and drinking
plan items (intentions on level of intoxication, place of planned drinking, social
purpose, and planned transportation) for the coming Friday and Saturday nights.
Finally, we included the Johnston et al. (2009) measure of heavy episodic drinking
(“In the past two weeks on how many occasions did you consume five or more
drinks at a single sitting?”). This variable was recoded into a yes/no variable
for our final analyses.
Our primary drinking intention item (included in the pre-event survey and
used in the Clapp et al., 2003, study) was: If you decide to drink (asked separately
for Friday and Saturday nights), do you think you will:
1. drink without feeling any effects from alcohol;
2. drink only enough to feel relaxed;
3. drink enough to feel a little buzzed;
4. drink enough to feel a little drunk; or
5. drink enough to feel very drunk?
(Those reporting either of the latter two choices were coded as positive for
intention to get drunk).
The variables measuring place of planned (pre-event interview) and actual
drinking (post-event drinking) included the following options:
1. in a bar;
2. in a restaurant;
3. in a fraternity or sorority house;
4. in an apartment or residence hall;
5. in a private apartment or house; or
6. some other place (specify).
For analytic purposes these categories were recoded into public (bar, restaurant,
other public places such as beach) and private (apartment, fraternity/sorority,
house, residence hall room) settings for the actual place of drinking.
The post-drinking event measure included items assessing (separate items
for each night) whether the respondent drank alcohol, and if so the total number
of drinks consumed (a drink was defined as 1.5 ounces of spirits, a 12-ounce
beer or malt beverage, a mixed drink containing one shot of spirits, or a 6-ounce
glass of wine). In addition, we asked a series of yes/no items related to the
DRINKING PLANS AND DRINKING OUTCOMES / 257
environmental characteristics of the event. Specifically we used the following
items in our analyses:
1. Was the event open to the public?
2. Was the event advertised?
3. Were most people standing?
4. Were most people at the event the same gender?
5. Were many people intoxicated?
6. Were people getting rowdy or out of hand?
7. Were illegal drugs available?
8. Were people playing drinking games?
9. Was food available?
In addition, we collected information concerning the availability of alcohol at
each event. Overall, beer was available at 85.4% of the events, wine or wine
coolers at 75% of the events, mixed drinks at 74.5% of the events, and shot
of spirits at 84.8% of the events.
The demographic variables included continuous measures of age and GPA,
as well as dichotomous measures of gender (male/female), ethnicity (Caucasian/
other), Greek affiliation (yes/no), being in a committed relationship (including
married; yes/no), and any heavy episodic drinking (HED) in the past 2 weeks
(yes/no). The predictor variable of most interest was self-report of intended
effects of drinking (drunk/not drunk) obtained prior to the event and HED
(5+ drinks) at the location of interest.
Data Analytic Plan
A series of analyses were conducted to answer the three primary research
questions of the study. In order to evaluate whether drinking intentions predicted
drinking environment characteristics as a function of self-reported drinking, four
a priori groups were created based on whether the respondent endorsed an
intention to get drunk that night and whether he/she consumed five or more
drinks (considered heavy episodic drinking). Thus we had groups reflecting:
1. no intent to get drunk/drank less than five drinks;
2. no intent to get drunk/drank more than five drinks;
3. intent to get drunk/drank fewer than five drinks; and
4. intent to get drunk/drank five or more drinks.
Group differences on both background demographics and drinking environ-
ment characteristics for the four intention-drinking groups were assessed using
a conservative Welch ANOVA F-test to account for unequal group variances.
For those outcomes with a significant omnibus Welch F-Test, the Games-Howell
post-hoc comparison procedure was used to account for unequal group sizes
and variances.
258 / TRIM ET AL.
To address the second research question, latent classes of college drinking
environments were identified using latent class analysis (LCA) on the nine binary
indicators used in the previous analyses, and several model fit statistics were
examined to assess the optimal number of extracted classes. Data simulations
have found that the bootstrapped parametric likelihood ratio test (BLRT) typically
outperformed other useful indexes such as Bayesian Information Criterion (BIC)
and Lo-Mendell-Rubin (LMR) adjusted LRT when identifying the correct number
of classes across mixture modeling approaches (Nylund, Asparouhov, & Muthen,
2007). These measures of relative model fit, and other informative indices such
as classification precision (entropy), were used to help determine the best-fitting
class solution for college drinking environments. The characteristics of each class
in the best-fitting solution were used to create a descriptive label for each drinking
environment subgroup. Finally, differences in demographics, intention to get
drunk, and heavy episodic drinking were estimated for individuals who reported
being in each of the drinking environment classes identified in the LCA.
The third aim of this article was to replicate and extend the Clapp et al. (2003)
study which found that drinking environment mediated the effect of drinking
motivations on college student drinking through traditional mediation testing
(Baron & Kenny, 1986) within an SEM framework. The current study seeks to
evaluate a similar mediation pathway from intention to get drunk to drinking
environment to heavy episodic drinking in college students using a product-of-
coefficients test known as the distribution of the product (MacKinnon, Warsi, &
Dwyer, 1995) in Mplus 5.1 (Muthen & Muthen, 1998-2006). Since the asym-
metric distribution of the product is not normally distributed, the bias-corrected
bootstrap test (with 1000 re-samples) was used to provide a more accurate estimate
of the range of potential values for the mediated effects; simulation studies
have recommended the use of this approach based on increased power to detect
“true” mediation effects (Fritz & MacKinnon, 2007). The values in the bootstrap
sample at the 2.5th and 97.5th percentile reflect the lower and upper limits of
the 95% confidence interval; mediation can be said to occur if this confidence
interval does not contain zero.
RESULTS
Examining Individual and Environmental Differences
across Subgroups Defined by Drinking Intentions
and Subsequent Heavy Episodic Drinking
For the first research question, 378 respondents were classified into one of
four groups based on:
1. their intention to get drunk that night; and
2. whether they engaged in heavy episodic drinking, i.e., consumed five or
more drinks that same night.
DRINKING PLANS AND DRINKING OUTCOMES / 259
The largest group consisted of 169 (44.7%) respondents who reported no intent
to get drunk and drank less than five drinks (Group 1), followed by 89 (23.5%)
respondents who reported no intent to get drunk, but consumed five or more
drinks (Group 2); 35 (9.3%) who intended to get drunk, but had less than five
drinks (Group 3); and 82 (22.5%) who intended to get drunk and had five or
more drinks (Group 4).
Table 1 illustrates the demographic differences across these groups. There was
a significant effect of group on gender (Welch F(3, 122.8) = 14.05, p < .001), age
(Welch F(3, 122.6) = 2.72, p < .05), relationship status (Welch F(3, 124.9) = 5.59,
p < .01), and recent heavy drinking (i.e., 5+ drinks at least on occasion in past
2 weeks; F(3, 124.9) = 19.41, p < .001). The Games-Howell post-hoc procedure
was used for the three variables with a significant omnibus test to account for
unequal group sizes and variances: Group 1 had a lower proportion of males than
both Groups 2 and 4 (31% vs. 58% and 68%); Group 1 was older than Group 3
(21.1 vs. 20.2 years); Group 1 had a higher proportion of subjects in a com-
mitted relationship compared to Group 4 (49% vs. 25%); and Group 1 had less
students with recent heavy drinking than Groups 2/3/4 (51% vs. 76%/82%/91%);
and Group 4 had a higher rate of recent heavy drinking compared to Group 2
(91% vs. 76%).
Table 2 shows the drinking location characteristics endorsed by each intention/
drinking group. There was a significant effect of group on the following qualities:
“most people standing” (F(3, 125.1) = 7.87, p < .001), “many people intoxicated”
(F(3, 125.2) = 30.80, p < .001), “rowdy or people getting a little out of hand”
(F(3, 116.7) = 9.68, p < .001), “illegal drugs available” (F(3, 108.7) = 7.37,
p < .001), “drinking games being played” (F(3, 119.3) = 9.72, p < .01), and “food
available” (F(3, 123.5) = 2.93, p < .05). In general, Groups 1 and 3 (no recent
heavy drinking) reported being in an environment with lower rates of “most
people standing,” “many people intoxicated,” “rowdy people,” and “drinking
games played” compared to those who consumed five or more drinks. Respon-
dents reporting “illegal drugs available” were highest in Groups 3 and 4 (those
groups intending to get drunk). Group 1 had a significantly higher rate of being
in a place with “food available” compared to Group 4.
Identifying Group Differences Across
Drinking Environment Subgroups
The second approach focused on first identifying latent classes of college
drinking environments based on nine binary indicators used in the previous
analyses. Results from a range of 2- to 5-class solutions were examined to
determine the best-fitting class solution. The bootstrapped parametric likelihood
ratio test (BLRT), when comparing a model with 4 classes to a model with
3 classes, had a p-value of < .001 and the Lo-Mendell-Rubin LRT had p = .01.
When comparing a model with 5 classes to a model with 4 classes, the BLRT was
260 / TRIM ET AL.
Tab
le1
.D
rin
kin
gIn
ten
tio
ns
an
dO
utc
om
es
by
Dem
og
rap
hic
Ch
ara
cte
ristics
(n=
37
5;
pro
po
rtio
ns)
GR
OU
P1
No
inte
nt
tog
et
dru
nk
an
d<
5d
rin
ks
(n=
16
9)
GR
OU
P2
No
inte
nt
tog
et
dru
nk
an
d5
+d
rin
ks
(n=
89
)
GR
OU
P3
Inte
nt
tog
et
dru
nk
an
d<
5d
rin
ks
(n=
35
)
GR
OU
P4
Inte
nt
tog
et
dru
nk
an
d5
+d
rin
ks
(n=
82
)
%m
ale
*
Ag
e*
%C
au
casia
n
GP
Ala
st
sem
este
r
%in
frat/
so
rori
ty
%in
co
mm
itte
dre
latio
nsh
ip*
%w
ith
HE
Din
past
2w
eeks
.31
a,b
21.1
a
.63
3.4 .1
4
.49
a
.51
a,b
,c
.58
b
21.0 .5
6
3.2 .1
1
.34
.76
a,d
.43
20.2
a
.54
3.2 .1
4
.43
.82
b
.68
a
21.1 .7
3
3.2 .2
1
.25
a
.91
c,d
*In
dic
ate
sa
sig
nific
an
t(p
<.0
5)
om
nib
us
gro
up
diffe
ren
ce
usin
gth
eW
elc
hte
st
toacco
un
tfo
ru
neq
ual
gro
up
vari
an
ces.
With
inth
ese
row
s,
gro
up
ssh
ari
ng
aco
effic
ien
tw
ere
sig
nific
an
tly
diffe
ren
t(p
<.0
5)
usin
gG
am
es-H
ow
ell
po
st-
ho
cp
roced
ure
toacco
un
tfo
ru
neq
ual
gro
up
siz
es
an
dvari
an
ces.
DRINKING PLANS AND DRINKING OUTCOMES / 261
Tab
le2
.D
rin
kin
gIn
ten
tio
ns
an
dD
rin
kin
gO
utc
om
es
by
En
vir
on
men
talC
hara
cte
ristics
(pro
po
rtio
ns)
GR
OU
P1
No
inte
nt
tog
et
dru
nk
an
d<
5d
rin
ks
(n=
16
9)
GR
OU
P2
No
inte
nt
tog
et
dru
nk
an
d5
+d
rin
ks
(n=
89
)
GR
OU
P3
Inte
nt
tog
et
dru
nk
an
d<
5d
rin
ks
(n=
35
)
GR
OU
P4
Inte
nt
tog
et
dru
nk
an
d5
+d
rin
ks
(n=
82
)
Fri
day/S
atu
rday
Pu
blic
even
t
Ad
vert
ised
Mo
st
peo
ple
sta
nd
ing
*
Mo
st
peo
ple
sam
eg
en
der
Man
yp
eo
ple
into
xic
ate
d*
Peo
ple
row
dy*
Ille
gald
rug
savaila
ble
*
Dri
nkin
gg
am
es
pla
yed
*
Fo
od
availa
ble
*
.63
.38
.12
.45
a,b
.18
.44
a,b
.05
a
.05
a,b
.10
a,b
.66
a
.64
.35
.12
.63
a
.19
.74
a,c
,d
.13
b
.17
a
.29
a
.53
.71
.29
.11
.40
c
.26
.43
c,e
.06
c
.23
.11
c
.63
.65
.39
.13
.72
b,c
.16
.90
b,d
,e
.33
a,b
,c
.24
b
.37
b.c
.49
a
*In
dic
ate
sa
sig
nific
an
t(p
<.0
5)
om
nib
us
gro
up
diffe
ren
ce
usin
gth
eW
elc
hte
st
toacco
un
tfo
ru
neq
ual
gro
up
vari
an
ces.
With
inth
ese
row
s,
gro
up
ssh
ari
ng
aco
effic
ien
tw
ere
sig
nific
an
tly
diffe
ren
t(p
<.0
5)
usin
gG
am
es-H
ow
ell
po
st-
ho
cp
roced
ure
toacco
un
tfo
ru
neq
ual
gro
up
siz
es
an
dvari
an
ces.
262 / TRIM ET AL.
not replicated and the Lo-Mendell-Rubin LRT had p = 0.38. Compared to the
5-class model, the BIC was lower for the 4-class model (4692 vs. 4723), and
both entropy (a measure of classification uncertainty where higher values are
preferred; 0.81 vs. 0.79) and the posterior probabilities for each class (84-96%
vs. 80-93%) were higher in the 4-class model. Taken together, these indices
suggest that four classes were sufficient in identifying unobserved heterogeneity
of drinking locations and five classes were not needed.
Results from the 4-class model are shown in Table 3. Through examination
of the class characteristics, these groups are best classified based on the public/
private status of the venue and presence of many intoxicated people. For naming
purposes, latent classes with a high proportion of respondents reporting “many
people were intoxicated” are labeled as “heavy.” Thus, we had the following
four classes:
1. Private/Light;
2. Public/Light;
3. Private/Heavy;
4. Public/Heavy.
The majority of respondents in the two “heavy” drinking classes (94%) charac-
terized the location as having “many people intoxicated” compared to 21-22% of
respondents endorsing this quality in “lighter” classes. Almost all respondents
agreed with the description of “most people standing” for Private/Heavy locations
compared to ~20% for the Private/Light and Public/Light classes. Respondents
in the Private/Light class endorsed the highest rates of “most people same gender”
at 30% compared to Private/Heavy class where this was rarely endorsed (8%).
The location with the highest probability of illegal drugs (19%) and drinking
games (50%) was Private/Heavy. Food was available at most locations with
few intoxicated people (79-91%) compared to rates of 35-44% at locations
with many intoxicated people (heavy locations).
Table 4 illustrates the demographic differences of respondents who reported
drinking in each type of environment. There was a significant effect of drinking
environment on gender (F(3, 160.8) = 2.65, p < .05), age (F(3, 168.4) = 5.77,
p < .01), ethnicity (F(3, 158.5) = 2.99, p < .05), relationship status (F(3, 157.5) =
11.68, p < .001), intent to get drunk (F(3, 163.4) = 7.84, p < .001), and heavy
drinking at the location (F(3, 161.2) = 27.16, p < .001).
Respondents who reported going to heavy locations were less likely to be in
a committed relationship compared to those in lighter locations (28/25% vs.
57/52%). Respondents in Public/Heavy venues were less likely to be Caucasian
(49%), compared to those who were in other types of drinking environments
(63-68%). Those who were in Public/Light were, on average, slightly older
(21.7 years) compared to individuals who were in private venues. Private/Heavy
venues had the highest proportion of males (57%), but this was not significantly
higher than the rates of males at public venues. Compared to locations with fewer
DRINKING PLANS AND DRINKING OUTCOMES / 263
Tab
le3
.Late
nt
Cla
sses
ofD
rin
kin
gE
nvir
on
men
tsb
yP
resen
ce
ofS
pecific
En
vir
on
men
talC
hara
cte
ristics
(pro
po
rtio
ns)
Cla
ss
1
(n=
12
1)
Pri
vate
/Lig
ht
Cla
ss
2
(n=
46
)
Pu
blic
/Lig
ht
Cla
ss
3
(n=
93
)
Pu
blic
/H
eavy
Cla
ss
4
(n=
11
5)
Pri
vate
/H
eavy
Ad
vert
ised
Mo
st
peo
ple
sta
nd
ing
Mo
st
peo
ple
sam
eg
en
der
Man
yp
eo
ple
into
xic
ate
d
Peo
ple
row
dy
Ille
gald
rug
savaila
ble
Dri
nkin
gg
am
es
pla
yed
Fo
od
availa
ble
.00
.19
.30
.21
.02
.12
.05
.79
.24
.22
.13
.22
.09
.07
.04
.91
.37
.99
.08
.94
.25
.13
.13
.35
.00
.70
.17
.94
.17
.19
.50
.44
264 / TRIM ET AL.
Tab
le4
.Late
nt
Cla
sses
ofD
rin
kin
gE
nvir
on
men
tsb
yD
em
og
rap
hic
Ch
ara
cte
ristics
(pro
po
rtio
ns)
Cla
ss
1
(n=
12
1)
Pri
vate
/Lig
ht
Cla
ss
2
(n=
46
)
Pu
blic
/Lig
ht
Cla
ss
3
(n=
93
)
Pu
blic
/H
eavy
Cla
ss
4
(n=
11
5)
Pri
vate
/H
eavy
%m
ale
*
Ag
e*
%C
au
casia
n
GP
Ala
st
sem
este
r
%in
frat/
so
rori
ty
%in
co
mm
itte
dre
latio
nsh
ip*
%w
ith
HE
Din
past
2w
eeks
Inte
nt
tog
et
dru
nk*
5+
dri
nks
at
locatio
n*
.45
21.0
a
.68
a
3.2 .1
5
.57
a,b
.71
.20
a,b
.23
a,b
.35
21.7
a,b
.63
3.1 .0
9
.52
c,d
.57
.17
c
.22
c,d
.43
21.2 .4
9a,b
3.5 .1
6
.28
a,c
.67
.37
a
.58
a,c
.57
20.6
b
.68
b
3.4 .1
6
.25
b,d
.78
.44
b,c
.69
b,d
*In
dic
ate
sa
sig
nific
an
t(p
<.0
5)
om
nib
us
gro
up
diffe
ren
ce
usin
gth
eW
elc
hte
st
toacco
un
tfo
ru
neq
ual
gro
up
vari
an
ces.
With
inth
ese
row
s,
gro
up
ssh
ari
ng
aco
effic
ien
tw
ere
sig
nific
an
tly
diffe
ren
t(p
<.0
5)
usin
gG
am
es-H
ow
ell
po
st-
ho
cp
roced
ure
toacco
un
tfo
ru
neq
ual
gro
up
siz
es
an
dvari
an
ces.
DRINKING PLANS AND DRINKING OUTCOMES / 265
intoxicated people, respondents at locations with many intoxicated people
reported higher rates of both intending to get drunk (44/37% vs. 20/17%) and
heavy episodic drinking (23/22% vs. 58/69%) while in that environment.
Testing for Mediating Effects of Drinking Environment
on the Relation Between Drinking Intentions
and Heavy Episodic Drinking
Mplus 5.1 software was used to evaluate the indirect effect of intention to
get drunk (dichotomous) on heavy episodic drinking (dichotomous) through
its impact on drinking environment (ordinal). Based on previous analyses, the
4-level latent class solution of drinking environment was retained as an ordinal
mediator variable reflecting an increase in contextual drinking risk ranging from
Private/Light to Private/Heavy. Note that similar results were found when this
4-level variable was collapsed into a dichotomous variable based on few versus
many people intoxicated. For a model with no additional predictors, the indirect
effect was significant (b = .258, se = .064, p < .001) and the 95% confidence
interval obtained from the bias-corrected bootstrap test did not include zero
(0.147, 0.396). When the set of seven covariates from the prior analyses were
controlled for, the indirect effect remained significant (b = .225, se = .077, p < .01;
95% CI = 0.078-0.390); note also that the direct paths from intention to get drunk
to drinking environment (b = .548, se = .124, p < .001), drinking environment
to recent heavy drinking (b = .470, se = .063, p < .001), and intention to get drunk
to recent heavy drinking (b = .668, se = .139, p < .001) were all significant even
after controlling for the effects of the covariates. These results suggest that
the effect of drinking intentions on recent heavy drinking is mediated through
qualities of the drinking environment.
DISCUSSION
This study builds on the extant research literature on person and environment
relationships related to drinking behavior. In summary, we found:
1. drinking intentions were inconsistent with drinking outcomes for about
one-third of this college sample;
2. drinking environments can be statistically classified on pubic/private and
light/heavy dimensions; and
3. drinking intentions are mediated by drinking environments.
Interestingly, as noted above, our results suggest drinking intentions do not
necessarily lead to the initially planned drinking outcomes. That is, it is fairly
common for college students to drink more (23.5%) or less than they intended
(9.3%). Young women were predictably over-represented among those who
intended to consume less than five drinks and subsequently reported drinking less
266 / TRIM ET AL.
than five drinks at the assessed event. Numerous other studies have found women
are less likely to engage in heavy episodic drinking (e.g., Johnston et al., 2009;
Wechsler, Lee, Kuo, Seibring, Nelson, & Lee, 2002). These gender patterns held
across the latent classes, with the exception of women being over-represented in
Public/Heavy settings. In previous studies (Clapp, Ketchie, Reed, Shillington,
Lange, & Holmes, 2008a, Clapp, Min, et al., 2008) we found that themed drinking
events (e.g., toga parties, etc.) resulted in heavy drinking among women, and
future research is needed to examine aspects of environments that may have
gender-specific effects. Also consistent with the literature on drinking events,
those with a history of heavy episodic drinking were more likely to drink five
or more drinks when they intended not to do so (Thombs et al., 2009).
The environmental characteristics associated with the drinking intention/
drinking sub-groups were very consistent with previous field research studies
(Clapp et al., 2000, 2006; Clapp, Min, et al., 2008). Specifically, having many
people intoxicated, rowdiness, drinking games being played, and illicit drugs
available were all associated with the heavier reported drinking classes. Similarly,
when the public versus private nature of the environment was combined with
reports of having “many people intoxicated” to define classes, reports of having
“many people intoxicated” were associated with heavier drinking, regardless
of public or private venue. In contrast, the presence of “drinking games” and
the availability of “illegal drugs” were most likely in private settings in which
respondents tended to report heavy drinking regardless of their drinking inten-
tions. Thus, these environmental characteristics tended to be present in settings
for those who intended to drink heavily and did, as well as for those who did not
intend to drink heavily but reported consuming five or more drinks. Consistent
with this finding and previous research (Clapp et al., 2003), our meditational
analysis indicated that drinking environment proved to mediate drinking inten-
tions and drinking outcomes (heavy episodic drinking).
Together, these results suggest the importance of considering both individual
level and environmental factors when developing both etiological models of
college drinking and prevention approaches. Consistent with this, numerous
researchers and governmental recommendations have encouraged comprehensive
“person and environment” or ecological models (Clapp et al., 2001; DeJong &
Langford, 2002; DeJong, Vince-Whitman, Colthurst, Cretella, Gilbreath, Rosati,
et al., 1998; Office of the Surgeon General, 2007; Task Force of the National
Advisory Council on Alcohol Abuse and Alcoholism, 2002) when considering
prevention approaches to college drinking problems. Although this study and
others like it have begun to examine such person/environment interactions,
the mechanisms underlying such relationships require further study to facilitate
prevention efforts. Understanding, for instance, why the perception of “many
intoxicated people” at events is a consistent indicator of drinking events in both
observational (Clapp, Min, et al., 2008) and self-report studies (Clapp et al., 2006)
might have implications for responsible host training. Further future research is
DRINKING PLANS AND DRINKING OUTCOMES / 267
needed to explore and develop prevention approaches that target specific factors
at both the person and the environmental level in a systematic way, especially in
light of the current findings that drinking environments mediate the effect of
planned intentions on drinking outcome. For instance, social host policies might
be combined with enforcement, media campaigns, party host training, and a
normative feedback approach to comprehensively intervene at both the individual
and environmental level of college drinking.
Compared to previous cross-sectional studies, the present study had several
strengths including a random sample of college age drinkers, collection of pre- and
post-drinking event data, and use of contemporary approaches to both latent
class and mediation analyses. Like most studies examining college or young
adult drinking, we relied on self-reports of drinking and drinking environments,
which is a limitation; however, the brief recall period between drinking events
and the interview might improve the reliability of self-reports. Although the
study might have limited external validity due to its limited geographic area and a
slightly older sample of students than found in other college drinking research,
the types of situations reported on by our sample are relatively typical for college
students. Thus, we believe the present study has good ecological validity.
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John Clapp, Ph.D.
Center for Alcohol and Drug Studies
6386 Alvarado Ct., Suite 224
San Diego, CA 92120
e-mail: [email protected]
270 / TRIM ET AL.