Assault related substance use as a predictor of substance use over time within a sample of recent victims of sexual assault

Abstract

Substance use at time of assault is reported by a significant subgroup of rape victims. This study examined: (1) prevalence of assault related marijuana or alcohol use among women seeking post-rape medical care; (2) sensitivity, specificity, positive and negative predictive power associated with reported use at time of assault in association with use in 6weeks pre-assault, post-assault use, and post-assault abuse; and (3) trajectories of use and abuse over time as a function of use in 6weeks pre-assault/assault time frame use, exposure to brief intervention, and interaction of pre-assault/assault time frame use with intervention. Participants were 268 women seeking post-sexual assault medical services completing one or more follow-up assessment at: (1) <3months post-assault; (2) 3 to 6months post-assault; and (3) 6months or longer post-assault. Use of alcohol or marijuana at time of assault was a fairly sensitive and specific indicator respectively, of reported use of specific substance in the 6weeks preceding assault and use or abuse at follow-up. Growth modeling revealed that use of alcohol or marijuana at the time of the assault or in the 6weeks prior to assault predicted higher Time 1 follow-up alcohol and marijuana use and abuse. Although there was relatively little change in use or abuse over time, alcohol use at time of the assault or in the 6weeks prior also predicted a steeper decline in alcohol use over the course of follow-up. Interestingly, women who reported using marijuana at the time of the assault or in the 6weeks prior who also received a video intervention actually had lower initial marijuana use, a pattern that remained stable over time. Implications for evaluating screening, brief intervention and referral to treatment services among sexual assault victims seeking post-assault medical care are discussed.