title: Effectiveness of guided and unguided low-intensity internet interventions for adult alcohol misuse: a meta-analysis.
abstract: BACKGROUND
  Alcohol misuse ranks within the top ten health conditions with the highest global burden of disease. Low-intensity, Internet interventions for curbing adult alcohol misuse have been shown effective. Few meta-analyses have been carried out, however, and they have involved small numbers of studies, lacked indicators of drinking within low risk guidelines, and examined the effectiveness of unguided self-help only. We therefore conducted a more thorough meta-analysis that included both guided and unguided interventions.
  
  
  METHODS
  Systematic literature searches were performed up to September 2013. Primary outcome was the mean level of alcohol consumption and drinking within low risk guidelines for alcohol consumption at post-treatment.
  
  
  RESULTS
  We selected 16 randomised controlled trials (with 23 comparisons and 5,612 participants) for inclusion. Results, showed a small but significant overall effect size in favour of Internet interventions (g = 0.20, 95% CI: 0.13-0.27, p<.001). Participants in Internet interventions drunk on average 22 grams of ethanol less than controls and were significantly more likely to be adhering to low-risk drinking guidelines at post-treatment (RD 0.13, 95% CI: 0.09-0.17, p<.001). Subgroup analyses revealed no significant differences in potential moderators for the outcome of alcohol consumption, although there was a near-significant difference between comparisons with waitlist control and those with assessment-only or alcohol information control conditions (p = .056).
  
  
  CONCLUSIONS
  Internet interventions are effective in reducing adult alcohol consumption and inducing alcohol users to adhere to guidelines for low-risk drinking. This effect is small but from a public health point of view this may warrant large scale implementation at low cost of Internet interventions for adult alcohol misuse. Moderator analyses with sufficient power are, however, needed in order to assess the robustness of these overall results and to assess whether these interventions may impact on subgroups with different levels of success.
authors.affiliation: Department of Clinical Psychology and EMGO Institute, VU University Amsterdam, Amsterdam, Netherlands; Division Health Trainings online, EU innovation Incubator, Leuphana University, Lüneburg, Germany.
authors.forename: Heleen
authors.initials: H
authors.lastname: Riper
authors.affiliation: Arkin Mental Health Care, Amsterdam, the Netherlands; Trimbos Institute, Netherlands Institute of Mental Health and Addiction, Utrecht, The Netherlands; Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Centre, University of Amsterdam, the Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Blankers
authors.affiliation: Department of Clinical Psychology and EMGO Institute, VU University Amsterdam, Amsterdam, Netherlands; TS Social and Behavioral Sciences, Department of Developmental Psychology, Tilburg University, Tilburg, the Netherlands.
authors.forename: Hana
authors.initials: H
authors.lastname: Hadiwijaya
authors.affiliation: Centre for Mental Health Research, the Australian National University, Canberra, Australia; Centre for Addiction and Mental Health, Toronto, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Cunningham
authors.affiliation: NHS Fife, Edinburgh, Scotland, United Kingdom.
authors.forename: Stella
authors.initials: S
authors.lastname: Clarke
authors.affiliation: Addiction, Development and Psychopathology (ADAPT) lab, Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Reinout
authors.initials: R
authors.lastname: Wiers
authors.affiliation: Division Health Trainings online, EU innovation Incubator, Leuphana University, Lüneburg, Germany; Division for Clinical Psychology and Psychotherapy, Department for Psychology, Philipp's University Marburg, Marburg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Ebert
authors.affiliation: Department of Clinical Psychology and EMGO Institute, VU University Amsterdam, Amsterdam, Netherlands; Division Health Trainings online, EU innovation Incubator, Leuphana University, Lüneburg, Germany.
authors.forename: Pim
authors.initials: P
authors.lastname: Cuijpers
mesh_terms: D000428:Alcohol Drinking / Q000517:prevention & control; D000437:Alcoholism / Q000628:therapy*; D015438:Health Behavior; D006801:Humans; D020407:Internet; D010349:Patient Compliance; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome