Motivational interviewing for alcohol misuse in young adults

Globally, harmful use of alcohol results in approximately 2.5 million deaths each year. About 9% of these deaths are young people between the ages of 15 and 29 years (WHO 2011), mainly resulting from motor vehicle accidents, homicides, suicides and drownings. Hazardous drinking levels for men (consuming over 40 g/day alcohol on average, that is 5 units) double the risk of liver disease, raised blood pressure, some cancers and violent death (because some people who have this average alcohol consumption drink heavily on some days). For women, over 24 g/day average alcohol consumption (3 units) increases the risk for developing liver disease and breast cancer. Motivational interviewing (MI) is a popular technique for addressing excessive drinking in young adults but its effectiveness has not previously been examined in a Cochrane review. The specific objectives were:(1) to summarise current evidence about the effects of MI intended to address alcohol and alcohol-related problems in young adults, compared with no intervention or a different intervention, on alcohol consumption and other substantive outcome measures;(2) to investigate whether the effects of MI are modified by the length of the intervention. Relevant evidence was identified from (1) Cochrane Central Register of Controlled Trials (CENTRAL) (October 2013), (2) MEDLINE (January 1966 to October 2013), (3) EMBASE (January 1988 to October 2013), and (4) PsycINFO (1985 to October 2013). References of topic-related systematic reviews and the included studies were handsearched. Randomised controlled trials and cluster randomised controlled trials of young people up to the age of 25 years in college and non-college settings comparing MIs with no intervention or a different intervention for prevention of alcohol misuse and alcohol-related problems were included. We used the standard methodological procedures expected by The Cochrane Collaboration. A total of 66 randomised trials (17,901 participants) were included four of which were cluster randomised. Studies with longer-term follow-up (four plus months) were of more interest when considering the sustainability of intervention effects.At four or more months follow-up, effects were found for the quantity of alcohol consumed (standardised mean difference (SMD) -0.14; 95% confidence interval (CI) -0.20 to -0.08 or a reduction from 13.7 drinks/week to 12.2 drinks/week), moderate quality of evidence; frequency of alcohol consumption (SMD -0.11; 95% CI -0.19 to