Risk modifying effect of social capital on measures of heavy alcohol consumption, alcohol abuse, harms, and secondhand effects: national survey findings.

STUDY OBJECTIVE To examine associations between social capital and individual risk for alcohol abuse and harms and identify protective effect mechanisms. DESIGN Multilevel multivariate analysis with individual level data from a national panel survey of drinking and a contextual measure of social capital reflecting college mean aggregate reports of student volunteerism. Outcomes include heavy episodic (binge) drinking, frequent drinking, frequent drunkenness, diagnosable alcohol abuse, intentional drunkenness, acquisition of binge drinking, harms, secondhand effects from others' drinking. SETTING United States, 119 four year colleges. PARTICIPANTS Representative samples of youth ages 18-24 surveyed in 1997 and 1999 using an anonymous mailed questionnaire (total n = 27 687). MAIN RESULTS Students from colleges with higher levels of social capital reported reduced risks for binge drinking (adjusted OR 0.38, 95% CI 0.20 to 0.69, p = 0.002), frequent drunkenness (adjusted OR 0.58, 95% CI 0.34 to 0.98, p = 0.04), acquisition of binge drinking in college (adjusted OR 0.48, 95% CI 0.24 to 0.95, p = 0.03), and alcohol abuse (adjusted OR 0.55, 95% CI 0.34 to 0.91, p = 0.02) in multilevel multivariate analyses that controlled for individual volunteering, the measure on which social capital was based. Higher levels of social capital protected against multiple drinking related harms (adjusted OR 0.51, 95% CI 0.29 to 0.90, p = 0.02) and secondhand drinking effects (adjusted OR, 0.30, 95% CI 0.16 to 0.58, p = 0.0003). Significant cross level interactions exist between fraternity/sorority membership and social capital for measures of risky drinking. Harm reduction primarily reflects consumption modification. CONCLUSIONS Social capital exerts strong protective effects on alcohol abuse and harm in college including among high risk students.