‘It’s not what you know but who you know’: Role of social capital in predicting risky injection drug use behavior in a sample of people who inject drugs in Baltimore City

Background: Injection drug use is the third highest risk factor for HIV transmission. Injection drug users, marginalized population, continue to be at threat for several health problems, including HIV, Hepatitis B and C, and drug overdose. The area of social capital and risk behaviors is understudied. The current study aims to prospectively assess the relationship between social capital and the risk behaviors associated with injection drug use (IDU). Methods: The sample of the present study is a subset of 130 drug users who reported IDU at both baseline and first follow-up wave for assessing the relationship between social capital and needle sharing in the city of Baltimore, MD. Factor analysis, structural equation modeling, and multivariate logistic regression were conducted to explore these relationships. Results: A single-factor model fits well with factor loadings ranging from 0.20 to 0.95. Social capital is shown to be significantly and inversely associated (p < 0.05) with 35% decreased odds of the risk of sharing needles with every unit increase in social capital (AOR: 0.65, 95% CI: 0.06, 0.84). Conclusion: The result from this study can be used to inform and fill gaps in the field of harm reduction. The interplay between social support, social participation and norms of trust, reciprocity generated from the index’s social network, and its relationship with behavior of needle sharing demonstrates that these leverage points should be emphasized in future harm reduction interventions.