AMERSA, San Francisco, October 2014
Internet-Based Primary
Prevention Intervention for
Alcohol Use: A Randomized
Trial
Nicolas Bertholet, MD, MSc
Alcohol Treatment Center,
Lausanne University Hospital
Switzerland
Study investigators
Lausanne University Hospital, Lausanne, Switzerland:
Alcohol treatment center, Department of community medicine and health:
Nicolas Bertholet
Jacques Gaume
Mohamed Faouzi
Jean-Bernard Daeppen
Gerhard Gmel
Clinical epidemiology center, Department of community medicine and health:
Bernard Burnand
Australian National University, Canberra, Australia,
and CAMH, Toronto, Canada:
John A. Cunningham
Introduction
• Preventing unhealthy alcohol use among young
individuals is of great interest in regards of the risk for
damaging consequences
• Over the past decade, there has been a large increase in
the development of internet or computer-based
interventions for unhealthy alcohol use
– Internet could be used to deliver primary prevention interventions
– Questions remain whether or not brief intervention including
feedback delivered to low risk drinkers may be harmful (potential
iatrogenic effect)
Introduction
• We proposed to test the impact of an
internet-based alcohol brief intervention
(IBI) in a general population sample of
young men with low risk alcohol use.
Low risk alcohol use was defined as:
Drinking <=14 drinks per week
AND
Absence of binge drinking (defined as one or more episode of
binge drinking (6 or more drinks/occasion) per month
AND
Alcohol Use Disorders Identification Test (AUDIT) score <=8
Methods
• Parallel-group randomized controlled trial
• Participants categorized as presenting low
risk alcohol use at baseline were randomized
(online) to receive the intervention or not.
• This took place immediately following
completion of the baseline assessment and
was unknown to the participants.
• Follow-up assessments at 1 and 6 months
after randomization.
• Entire study was done electronically.
Sample
• The trial took advantage of the ongoing Cohort study on
Substance Use Risk Factors (C-SURF).
• Switzerland has mandatory army conscription for all 19year-old males. Because there is no pre-selection for
army conscription, this offers a unique opportunity to
access the entire Swiss population of this age group.
• C-SURF cohort members were recruited between
August 2010 and July 2011
• In 2012, C-SURF participants were invited to participate
in the randomized trial (3mo after their last C-SURF
assessment)
Primary Prevention Internet-based brief
intervention (PPIBI) adapted from www.alcooquizz.ch
-
Normative feedback
-
-
Feedback on reported consequences (if any reported)
Calorific value of reported consumption (if the participant reported
drinking)
Computed blood alcohol concentration
-
-
-
Comparison of the participant’s alcohol consumption per week and per occasion
to the consumption of individuals of the same age in the Swiss population)
Based on maximum reported alcohol consumption (if any reported), and potential
consequences
Indication of the absence of unhealthy alcohol use, with indication
that the reported alcohol use (if any) is associated with no or limited
risks for health.
Message that no change in their current use of alcohol is necessary
and encouragement not to increase the current alcohol use
Outcomes
• Primary outcomes (at 1 and 6 months) were
- prevalence of monthly binge drinking
- weekly alcohol use (mean number of drinks per week)
• Secondary outcomes (at 6 months) were
- AUDIT score (timeframe adapted for 6 months)
- number of alcohol-related consequences (0 to 12)
Analyses
• The intervention impact was assessed
with:
– Chi-square test (binge drinking prevalence)
– Random-effects negative binomial model (number of
drinks/week)
Army recruitment centers attendees, Swiss
young males (n=13,245)
C-SURF participants (n=5,990)
Individuals invited to participate (n=4,365)
Did not access the
website (n=2278) or
declined participation
(n=724)
Individuals completing the baseline assessment
(n=1633) 37.4%
Unhealthy alcohol use
(n=737) 45.1%
Low risk alcohol use (n=896) 54.9%%
Control (n=445)
Intervention (n=451)
Control, 1 mo assessment (n=421) 94.6%
Intervention, 1 mo assessment (n=423) 93.8%
Control, 6 mo assessment (n=414) 93.0%
Intervention, 6 mo assessment (n=421) 93.3%
Results
• 896 young men with low risk alcohol use
were randomized.
• Follow-up rates were 94% at 1 month and
93% at 6 months.
Results: baseline characteristics
Full sample (n=896)
Age
21.0 (1.3)
Linguistic region:
French speaking
521 (58.2%)
German speaking
375 (41.9%)
Number of drinks/week, mean(SD)
2.3 (2.2)
Binge drinking, n (%)
0 (0%)*
AUDIT score, mean (SD)
3.5 (2.1)
Number of alcohol consequences (0-12), mean (SD)
1.0 (1.1)
* By definition (inclusion criteria)
Results: primary outcomes
Prevalence of binge drinking
Baseline
1mo
6mo
Intervention
0%
14.4%
13.3%
Control
0%
19.0%
13.0%
•Small protective intervention effect at 1mo (chi
square=3.18, p=0.07)
Results: primary outcomes
Number of drinks/week
Baseline
1mo
6mo
Intervention
2.4 (2.2)
2.3 (2.6)
2.5 (3.0)
Control
2.4 (2.3)
2.8 (3.7)
2.7 (3.9)
Results: primary outcomes
Number of drinks/week
NUMBER OF DRINKS/WEEK*
Control group, 1 month
Control group, 6 months
Intervention group, 1 month
Intervention group, 6 months
Between group tests
Intervention 1mo vs. Control 1mo
Intervention 6mo vs. Control 6mo
Intervention 1mo vs. Intervention 6mo
Control 1mo vs. Control 6mo
IRR
1.07
1.03
0.95
1.03
Chi2
3.60
0.00
2.79
0.40
95%CI
0.97; 1.17
0.94; 1.13
0.86; 1.04
0.94; 1.13
p
0.06
1.0
0.09
0.5
* random-effects negative binomial regression model adjusted for age and linguistic region
z
1.39
0.71
-1.16
0.64
p
0.1
0.5
0.2
0.5
Results: primary outcomes
Number of drinks/week
NUMBER OF DRINKS/WEEK*
Control group, 1 month
Control group, 6 months
Intervention group, 1 month
Intervention group, 6 months
Between group tests
Intervention 1mo vs. Control 1mo
Intervention 6mo vs. Control 6mo
Intervention 1mo vs. Intervention 6mo
Control 1mo vs. Control 6mo
IRR
1.07
1.03
0.95
1.03
Chi2
3.60
0.00
2.79
0.40
95%CI
0.97; 1.17
0.94; 1.13
0.86; 1.04
0.94; 1.13
p
0.06
1.0
0.09
0.5
z
1.39
0.71
-1.16
0.64
•Intervention effect on the number of drinks/week at 1 month
* random-effects negative binomial regression model adjusted for age and linguistic region
p
0.1
0.5
0.2
0.5
Limitations and… strengths
• Limitations:
– Self-report
– Very short assessment (but extensive
assessment in the cohort study)
• Strength:
– Sample
– High follow up rate
Conclusions
• There was no iatrogenic effect.
• Immediate effects following a PPIBI conducted
among young men in the general population are
plausible, but were not maintained at longer
term.
Funding
• The randomized trial was funded by the Swiss National
Science Foundation (grant 325130_135538/1, PI: N
Bertholet)
• The study intervention (website) was developed in part
with funds from a grant from the Department of
community medicine and health (to N Bertholet)
• C-SURF funded by the Swiss National Science
Foundation (33CSCO-122679, PI: G Gmel)
• Both studies were approved by the Ethics Committee for
Clinical Research of the Lausanne University Medical
School
Thank you
contact: Nicolas.Bertholet@chuv.ch
Acknowledgments:
N Sanchez: project manager
J Stierli, S Huber, M Dubi:
research assistants
R Borloz: administrative
assistant
S & J Szabo, M Grand
d’Hauteville, D Gartner:
web-design & development
M Rège-Walther
C Eidenbenz: project
manager C-SURF
C-SURF team
Participants