Background:
Interpersonal violence (IPV) among substance use disorder (SUD) patients is common, undertreated, and costly. SUD patients have high rates of perpetrating IPV, and IPV is a risk factor for poor response to SUD treatment. Failure to address IPV among SUD patients interferes with treatment effectiveness and contributes to relapse and higher rates of health services use. Nonetheless, SUD treatment programs typically do not include violence prevention interventions and few studies have examined interventions designed to prevent violence perpetration among SUD patients.
Objectives:
This trial evaluated the effectiveness of an IPV-prevention (IPV-P) intervention among patients entering VA SUD treatment who had perpetrated violence in the past year against another adult. Primary objectives were to test the hypotheses that, compared to patients assigned to a control condition (CC), those assigned to IPV-P would (1) improve more on violence and SUD outcomes, and (2) use fewer VA mental health and medical care services, thereby saving costs for VA. Secondary objectives were to test the hypothesis that, compared to patients assigned to CC, those assigned to IPV-P would improve more on legal and alienation problems and social resources.
Methods:
Patients entering VA SUD treatment who met eligibility criteria (past-year violence; cognitively intact) and provided informed consent were assigned to SUD usual care plus either a CC (N=60) or IPV-P (N=59) intervention using a recurrent institutional design. That is, the IPV-P and CC conditions were run in alternate 3-month periods. The manualized IPV-P group intervention, based on a Cognitive-Behavioral approach, consisted of 8 in-person group sessions over 1 month, followed by telephone calls once a month for 3 months. The manualized CC was designed to control for non-specific treatment effects associated with the IPV-P condition, i.e., counselor time and attention, peer support, patients' expectations that additional sessions provide benefit. It consisted of 8 in-person group sessions over 1 month that reviewed material covered in usual SUD treatment, but with novel methods used to deliver the IPV-P intervention (role-play, homework, group activities). CC included the booster telephone sessions (once per month for 3 months). Participants were assessed at baseline and end-of-intervention (4 months post-baseline) and 6 and 12 months post-intervention (i.e., 10 and 16 months post-baseline) for primary and secondary outcomes and non-VA healthcare. Assessments consisted of the Addiction Severity Index (ASI, to assess Alcohol, Drugs, Psychiatric, and Legal functioning), the Conflicts Tactics Scale (CTS, to assess Psychological Aggression and Physical Assault against another adult), the Multidimensional Personality Questionnaire (MDQ, to assess Alienation, Stress Reaction, and Aggression), and the Life Stressors and Social Resources Inventory (LISRES, to assess family and friends resources). VA health care is being assessed with VA databases. Response rates at 4, 10, and 16 months were 90%, 79%, and 73%, respectively, and did not differ between the IPV-P and CC groups. Follow-up analyses compared the IPV-P to the CC group on outcomes using analyses of covariance that controlled for the baseline value of the outcome.
Status:
We are still completing portions of this project: (1) conducting mixed effects regression analyses to compare the CC and IPV-P groups on primary and secondary outcomes (these analyses are partially completed), and (2) using data on VA health care utilization to compare the two groups on VA health care costs (permission to download these data has been obtained, and we are working with HERC investigators to download and analyze the data).
