internet-based primary prevention intervention for alcohol use: a randomized trial nicolas...

Internet-Based Primary Prevention Intervention for Alcohol Use: A Randomized Trial

Nicolas Bertholet, MD, MSc

Alcohol Treatment Center, Lausanne University HospitalSwitzerland

AMERSA, San Francisco, October 2014

Study investigatorsLausanne 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 19-

year-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- 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)

- Feedback on reported consequences (if any reported)- Calorific value of reported consumption (if the participant reported

drinking)- Computed blood alcohol concentration

- 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 completing the baseline assessment (n=1633) 37.4%

Low risk alcohol use (n=896) 54.9%%

Unhealthy alcohol use (n=737) 45.1%

Did not access the website (n=2278) or

declined participation (n=724)

Intervention, 6 mo assessment (n=421) 93.3%Control, 6 mo assessment (n=414) 93.0%

Intervention, 1 mo assessment (n=423) 93.8%Control, 1 mo assessment (n=421) 94.6%

Intervention (n=451)Control (n=445)

Individuals invited to participate (n=4,365)

Results

• 896 young men with low risk alcohol use were randomized.

• Follow-up rates were 94% at 1 month and 93% at 6 months.

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)

Results: baseline characteristics

* 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 outcomesNumber 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 outcomesNumber of drinks/week

NUMBER OF DRINKS/WEEK*IRR 95%CI z p

Control group, 1 month 1.07 0.97; 1.17 1.39 0.1Control group, 6 months 1.03 0.94; 1.13 0.71 0.5Intervention group, 1 month 0.95 0.86; 1.04 -1.16 0.2Intervention group, 6 months 1.03 0.94; 1.13 0.64 0.5Between group tests Chi2 pIntervention 1mo vs. Control 1mo 3.60 0.06Intervention 6mo vs. Control 6mo 0.00 1.0Intervention 1mo vs. Intervention 6mo 2.79 0.09Control 1mo vs. Control 6mo 0.40 0.5

* random-effects negative binomial regression model adjusted for age and linguistic region

Results: primary outcomesNumber of drinks/week

NUMBER OF DRINKS/WEEK*IRR 95%CI z p

Control group, 1 month 1.07 0.97; 1.17 1.39 0.1Control group, 6 months 1.03 0.94; 1.13 0.71 0.5Intervention group, 1 month 0.95 0.86; 1.04 -1.16 0.2Intervention group, 6 months 1.03 0.94; 1.13 0.64 0.5Between group tests Chi2 pIntervention 1mo vs. Control 1mo 3.60 0.06Intervention 6mo vs. Control 6mo 0.00 1.0Intervention 1mo vs. Intervention 6mo 2.79 0.09Control 1mo vs. Control 6mo 0.40 0.5

* random-effects negative binomial regression model adjusted for age and linguistic region

•Intervention effect on the number of drinks/week at 1 month

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 managerJ Stierli, S Huber, M Dubi: research assistantsR Borloz: administrative assistantS & J Szabo, M Grand d’Hauteville, D Gartner: web-design & developmentM Rège-WaltherC Eidenbenz: project manager C-SURFC-SURF teamParticipants