Men’s and women’s response to treatment and perceptions of outcomes in a randomized controlled trial of injectable opioid assisted treatment for severe opioid use disorder

Abstract

BackgroundTo test whether there are gender differences in treatment outcomes among patients receiving injectable opioids for the treatment of long-term opioid-dependence. The study additionally explores whether men and women have different perceptions of treatment effectiveness.MethodsThis study is a secondary analysis from SALOME, a double-blind, phase III, randomized controlled trial testing the non-inferiorirty of injectable hydromorphone to injectable diacetylmorphine among 202 long-term street opioid injectors in Vancouver (Canada). Given this was a secondary analysis, no a priori power calaculation was conducted. Differences in baseline characteristics and six-month treatment outcomes (illicit heroin use, opioid use, crack cocaine use, non-legal activities, physical and psychological health scores, urine positive for street heroin markers, and retention) were analysed by gender using fitted models. Responses to an open ended question on reasons for treatment effectiveness were explored with a thematic analysis.ResultsMen and women differed significantly on a number of characteristics at baseline. For example, women were significantly younger, presented to treatment with significantly higher rates of prior month sex work (31.5% vs. 0%), and used significantly more crack cocaine (14.71 vs. 8.38 days). After six-months of treatment there were no significant differences in treatment outcomes by gender, after adjusting for baseline values. For both men and women, improved health and quality of life were the most common reasons provided for treatment effectiveness, however women were more specific in the types of health improvements.ConclusionsDespite presenting to treatment with vulnerabilities not faced to the same extent by men, at six-months women did not differ significantly from men in tested trial efficacy outcomes. While the primary outcome in the trial was the reduction of illicit opioid use, in the open-ended responses both men and women focused their comments on improvement in health and quality of life as reasons for treatment effectiveness. The supervised model of care with injectable medications provides a particularly suitable framework for providing care to opioid-dependent men and women not attracted or retained by other treatments. The absence of statistical differences reported in this secondary analysis may be due to lack of adequate statistical power to detect meaningful effects.Trial registrationThis trial is registered with ClinicalTrials.gov (NCT01447212) Registered: October 4, 2011 at the following link: https://clinicaltrials.gov/ct2/show/NCT01447212.

“It’s Helped Me a Lot, Just Like to Stay Alive”: a Qualitative Analysis of Outcomes of a Novel Hydromorphone Tablet Distribution Program in Vancouver, Canada

“…Indeed, studies on heroin assisted treatment in both Canada and Europe have found that diacetylmorphine is more effective than oral methadone for reducing illicit opioid use for many individuals [ 31 , 49 , 51 , 52 ], indicating the need to expand opioid substitution models. Further, our study builds on research demonstrating a reduction in illegal activities (e.g., property crime, illegal means of income generation) among people receiving injectable opioid-assisted treatment [ 53 – 55 ]. This is especially important considering the association between socio-environmental factors, such as poverty, lack of adequate housing, and overdose risk [ 56 – 59 ], and underscores the potential role of safer supply interventions to address issues at the intersection of drug use and structural vulnerability.…”

Evidence on the Effectiveness of Heroin-Assisted Treatment

“…There was little evidence of differences between the supervised injectable heroin and supervised injectable hydromorphone groups across all other secondary outcome comparisons (Oviedo-Joekes et al, 2016). Subgroup analyses by gender or by self-identified Indigenous status showed no significant differences in treatment efficacy across primary or secondary outcomes (Oviedo-Joekes et al, 2017b;Palis et al, 2017).…”

“…Our literature search identified five additional articles evaluating the individual-level impacts of HAT based on the Study to Assess Longer-term Opioid Medication Effectiveness (SALOME) (Nikoo et al, 2018;Oviedo-Joekes et al, 2017a;Oviedo-Joekes et al, 2016;Oviedo-Joekes et al, 2017b;Palis et al, 2017), a more recent HAT RCT which did not have published results until after the most recent systematic review.…”

An emergency response to the opioid overdose crisis in Canada: a regulated opioid distribution program

“…6 The effectiveness of this program is supported by the rigorous scientific evaluation coming out of the Study to Assess Longerterm Opioid Medication Effectiveness (SALOME) trial, as well as several other heroin-assisted therapy trials. 7 However, the program has limitations with respect to scale-up, owing to the high cost of injectable hydromorphone, the infrastructure requirements and that participants must attend a medical clinic up to three times per day. In an effort to expand access to injectable opioid agonist therapy, a guideline has been developed to support new models for distribution that aim to lower both the barriers to qualify and the requirements to participate.…”