Transitions to Injecting Drug Use among Mexican American Noninjecting Heroin Users.

This paper determines the incidence and predictors of transitions to injecting drug use among a sample of noninjecting heroin users (NIUs). Three hundred street-recruited NIUs in San Antonio were interviewed in a prospective cohort study (three time periods: baseline, follow-up 1 and follow-up 2 at 6 month intervals). For the purpose of this analysis, a transition to injecting was identified as the first drug injection episode following baseline. Given the important distinction between former injectors and never injectors, hazards ratios are estimated by Cox proportional hazards regression, stratified by baseline injecting history. Analyses examine the rate of transitioning to injecting drug use, and the predictors of such transition rates with emphasis on the extent to which NIUs' interpersonal relationships (NIUs' personal social networks) with friends, kin and gang members, adherence to cultural values and norms, risk behaviors and personal susceptibility influence the relative risk for transitioning to injecting. Findings indicate the important role social networks play in influencing and facilitating transitioning to injecting among this population. These data will provide information that can be used to develop network-based interventions that can be conducted not only among couples and friendship groups, but also at the community-wide level through the diffusion of norms and practices among large numbers of NIUs to prevent the transition of injecting and other harmful health consequences of non-injecting heroin use. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]