Social network heavy drinking moderates the effects of a brief motivational intervention for alcohol use among injured patients.

Background: Limited research has focused on identifying the extent to which social networks impact the effectiveness of brief alcohol interventions delivered in trauma care settings.

Objectives: The research presented here examines the extent to which the percent of heavy drinkers and percent of abstainers in one's social network moderates the effectiveness of a brief motivational intervention with and without a telephone booster on alcohol use among trauma patients.

Method: Secondary data analyses were conducted using data from 596 participants (456males) who were recruited from three urban Level I trauma centers. Patients were randomized to one of the three intervention conditions: brief advice (BA; n = 200), brief motivational intervention (BMI; n = 203), and BMI with a telephone booster (BMI + B; n = 193). For the purpose of the present study, measures of alcohol-specific social network characteristics at baseline and alcohol use at 3- and 6-month follow-up were used.

Results: At low percentages (0% to ~7%) of people in one's social network who are heavy drinkers, there was a negative, statistically significant effect of the BMI conditions versus the BA condition on alcohol use. However, percent of abstainers did not moderate the effects of the BMI conditions.

Conclusion: The results suggest that the BMI and BMI + B conditions may be most effective among patients with no heavy drinkers in their social networks. BMIs may benefit from including a component that addresses having one or more heavy drinkers in one's social network.