The SALOME study: recruitment experiences in a clinical trial offering injectable diacetylmorphine and hydromorphone for opioid dependency

The Impact of Injectable Opioid Agonist Treatment (iOAT) on Involvement in Criminalized Activities: A Secondary Analysis from a Clinical Trial in Vancouver, BC

Purpose

A significant portion of the economic consequences of untreated Opioid Use Disorder (OUD) relate to individuals' involvement in the criminal justice system. The present study uncovers if treatment with iOAT is related to the number of criminal charges amongst participants, what type of crime participants were involved in, and the frequency with which participants were victims of crime. This study contributes to the body of research on the effectiveness of iOAT reducing criminal involvement.

Patients and Methods

This is a secondary analysis of police record data obtained from the Vancouver Police Department over a three-year period during the Study to Assess Longer-term Opioid Medication Effectiveness clinical trial. The data was obtained from participants (N = 192) enrolled in the trial through a release of information form.

Results

During the three-year period, most charges (45.6%) were property offences, and 25.5% of participants were victims of crime. Participants with no treatment prior to randomization into the SALOME trial were 2.61 (95% CI = 1.64-4.14) more likely to have been charged with a crime than during the iOAT state.

Conclusion

IOAT can reduce individuals' involvement with the criminal justice system and is thus a crucial part of the continuum of care. Addiction should be conceptualized as a healthcare rather than criminal issue.

Are adolescents and young adults in substance use disorder treatment as engaged in the research recruitment process as those in general behavioral health treatment?

BACKGROUND AND OBJECTIVE

While prior research suggests that individuals with substance use disorders (SUD) are generally more difficult to engage in research, little is known about the research engagement of adolescents and young adults (AYA) in SUD treatment as it compares to peers seen in general behavioral health settings. This study aimed to systematically compare engagement in virtual research recruitment between AYA in SUD treatment and AYA in behavioral health (BH) treatment.

METHODS

Study staff contacted patients ages 16-30 at three outpatient clinics to recruit them for a naturalistic longitudinal online study. Staff documented whether patients answered the phone, expressed interest in the study, answered questions regarding eligibility, and enrolled in the study.

RESULTS

Overall, 18% (n = 117) of those contacted by phone enrolled in the study. The rate of AYA reached did not significantly differ between those in SUD treatment (51%) and those in BH treatment (55%). Among those who were reached, those in SUD and BH treatment did not significantly differ (all p > 0.05) in rates of being interested in the study (SUD: 58%; BH: 49%), completing the phone screen (SUD: 46%; BH: 41%) or enrolling in the study (SUD: 33%; BH: 35%).

CONCLUSIONS

Overall, we found that engaging AYA in SUD treatment in virtual naturalistic longitudinal research was no more difficult than engaging AYA seen in general behavioral health settings. Future research should examine generalizability of engagement in naturalistic research to other study designs and explore the continuity of this effect into study retention and completion.

Perceptions of injectable opioid agonist treatment (iOAT) among people who regularly use opioids in Australia: findings from a cross-sectional study in three Australian cities

BACKGROUND AND AIMS

Not all people experiencing opioid dependence benefit from oral opioid agonist treatment. The aim of this study was to examine perceptions of (supervised) injectable opioid agonist treatment (iOAT) (described as 'an opioid similar to heroin self-injected at a clinic several times a day') among people who regularly use opioids and determine how common iOAT eligibility criteria accord with interest in iOAT.

DESIGN

Cross-sectional survey SETTING: Sydney, Melbourne and Hobart, Australia PARTICIPANTS: A total of 344 people (63% male) who use opioids regularly and had ever injected opioids, interviewed December 2017-March 2018. The mean age of participants was 41.5 years [standard deviation (SD) = 8.5].

MEASUREMENTS

Primary outcome measures were interest in iOAT, factors associated with interest and the proportion of participants who would be eligible using common criteria from trials and guidelines. We examined willingness to travel for iOAT, medication preferences and perspectives on whom should receive iOAT.

FINDINGS

Overall, 53% of participants (n = 182) believed that iOAT would be a good treatment option for them. Participants who believed that iOAT was a good treatment option for them were more likely to be male [adjusted odds ratio (aOR) = 1.76, 95% confidence interval (CI) = 1.10-2.82], have used heroin in the past month (aOR = 6.03, 95% CI = 2.86-12.71), currently regularly inject opioids (aOR = 1.84, 95% CI = 1.16-2.91) and have met ICD-10 criteria for opioid dependence (aOR = 3.46, 95% CI = 1.65-7.24). Those interested in iOAT had commenced more treatment episodes (aOR =1.06, 95% CI = 1.00-1.12). Among those interested in iOAT (n = 182), 26% (n = 48) met common eligibility criteria for iOAT.

CONCLUSIONS

Interest in injectable opioid agonist treatment does not appear to be universal among people who regularly use opioids. Among study participants who expressed interest in injectable opioid agonist treatment, most did not meet common eligibility criteria.

Impact of opioid agonist treatment on mental health in patients with opioid use disorder: a systematic review and network meta-analysis of randomized clinical trials

Background: There is a knowledge gap in systematic reviews on the impact of opioid agonist treatments on mental health.Objectives: We compared mental health outcomes between different opioid agonist treatments and placebo/waitlist, and between the different opioids themselves.Methods: This meta-analysis of randomized clinical trials (RCTs) was pre-registered at PROSPERO (CRD42018109375). Embase, MEDLINE, PsychInfo, CINAHL Complete, and Web of Science Core Collection were searched from inception to May 2020. RCTs were included if they compared opioid agonists with each other or with placebo/waitlist in the treatment of patients with opioid use disorder and reported at least one mental health outcome after 1-month post-baseline. Studies with psychiatric care, adjunct psychotropic medications, or unbalanced psychosocial services were excluded. The primary outcome was overall mental health symptomatology, e.g. Symptom Checklist 90 total score, between opioids and placebo/waitlist. Random effects models were used for all the meta-analyses.Results: Nineteen studies were included in the narrative synthesis and 15 in the quantitative synthesis. Hydromorphone, diacetylmorphine (DAM), methadone, slow-release oral morphine, buprenorphine, and placebo/waitlist were among the included interventions. Based on the network meta-analysis for primary outcomes, buprenorphine (SMD (CI95%) = -0.61 (-1.20, -0.11)), DAM (-1.40 (-2.70, -0.23)), and methadone (-1.20 (-2.30, -0.11)) were superior to waitlist/placebo on overall mental health. Further direct pairwise meta-analysis indicated that overall mental health improved more in DAM compared to methadone (-0.23 (-0.34, -0.13)).Conclusions: Opioid agonist treatments used for the treatment of opioid use disorder improve mental health independent of psychosocial services.

Three-month outcomes from a patient-centered program to treat opioid use disorder in Iowa, USA

BACKGROUND

Opioid use disorder (OUD), a chronic disease, is a major public health problem. Despite availability of effective treatment, too few people receive it and treatment retention is low. Understanding barriers and facilitators of treatment access and retention is needed to improve outcomes for people with OUD.

OBJECTIVES

To assess 3-month outcomes pilot data from a patient-centered OUD treatment program in Iowa, USA, that utilized flexible treatment requirements and prioritized engagement over compliance.

METHODS

Forty patients (62.5% female: mean age was 35.7 years, SD 9.5) receiving medication, either buprenorphine or naltrexone, to treat OUD were enrolled in an observational study. Patients could select or decline case management, counseling, and peer recovery groups. Substance use, risk and protective factors, and recovery capital were measured at intake and 3 months.

RESULTS

Most participants reported increased recovery capital. The median Assessment of Recovery Capital (ARC) score went from 37 at enrollment to 43 (p < 0.01). Illegal drug use decreased, with the median days using illegal drugs in the past month dropping from 10 to 0 (p < 0.001). Cravings improved: 29.2% reported no cravings at intake and 58.3% reported no cravings at 3 months (p < 0.001). Retention rate was 92.5% at 3 months. Retention rate for participants who were not on probation/parole was higher (96.9%) than for those on probation/parole (62.5%, p = 0.021).

CONCLUSION

This study shows preliminary evidence that a care model based on easy and flexible access and strategies to improve treatment retention improves recovery capital, reduces illegal drug use and cravings, and retains people in treatment.

Adverse Events During Treatment Induction With Injectable Diacetylmorphine and Hydromorphone for Opioid Use Disorder

OBJECTIVES

The present study aims to describe a 3-day induction protocol for injectable hydromorphone (HDM) and diacetylmorphine (DAM) used in 3 Canadian studies and examine rates of opioid-related overdose and somnolence during this induction phase.

METHODS

The induction protocol and associated data on opioid-related overdose and somnolence are derived from 2 clinical trials and one cohort study conducted in Vancouver and Montreal (2005-2008; 2011-2014; 2014-2018). In this analysis, using the Medical Dictionary for Regulatory Activities coding system we report somnolence (ie, drowsiness, sleepiness, grogginess) and opioid overdose as adverse events. Overdoses requiring intervention with naloxone are coded as severe adverse events.

RESULTS

Data from the 3 studies provides a total of 1175 induction injections days, with 700 induction injection days for DAM, and 475 induction injection days for HDM. There were 34 related somnolence and adverse event (AE) overdoses (4.899 per 100 injection days) in DAM and 6 (1.467 per 100 days) in HDM. Four opioid overdoses requiring naloxone (0.571 per 100 injection days) were registered in DAM and 1 in HDM (0.211 per 100 injection days), all safely mitigated onsite. The first week maximum daily dose patients received were on average 433.62 mg [standard deviation (SD) = 137.92] and 223.26 mg (SD = 68.06) for DAM and HDM, respectively.

CONCLUSIONS

A 3-day induction protocol allowed patients to safely reach high doses of injectable hydromorphone and diacetylmorphine in a timely manner. These findings suggest that safety is not an evidence-based barrier to the implementation of treatment with injectable hydromorphone and diacetylmorphine.

Heating Injection Drug Preparation Equipment Used for Opioid Injection May Reduce HIV Transmission Associated With Sharing Equipment

Supplemental Digital Content is Available in the Text.

Background:

London, Canada, experienced an HIV outbreak among persons who inject drugs despite widespread distribution of harm reduction equipment. Hydromorphone controlled-release (HMC) is the local opioid of choice. Injection drug preparation equipment (IDPE; ie, cookers and filters) is often shared and reused because of the perception that there is residual HMC in the IDPE after use. The purpose of this study was to investigate the mechanisms of HIV transmission in this context.

Methods:

Residual hydromorphone, (controlled-release or immediate-release), remaining in the IDPE, was measured with liquid chromatography–tandem mass spectrometry, in conditions replicating persons who inject drug use. HIV was added to IDPE in the presence HMC, hydromorphone immediate-release, or microcrystalline cellulose (an HMC drug excipient). HIV viral persistence was measured by reverse transcriptase activity and infectivity of indicator Tzm-bl cells.

Results:

Forty-five percent of HMC remained in the IDPE after the first aspiration of solution, with no change after heating. HIV persistence and infectivity were preserved in the presence of HMC, and less so with microcrystalline cellulose. Heating the IDPE rapidly inactivated HIV.

Conclusions:

Sharing of IDPE is a potential means of HIV transmission. HMC encourages IDPE sharing because of the residual drug in the IDPE, and the HMC excipients preserve HIV viability. Heating IDPE before aspiration of the opioid may be a harm reduction strategy.

Chronic Methadone Use Alters the CD8+ T Cell Phenotype In Vivo and Modulates Its Responsiveness Ex Vivo to Opioid Receptor and TCR Stimuli

Endogenous opioid peptides are released at sites of injury, and their cognate G protein-coupled opioid receptors (ORs) are expressed on immune cells. Although drugs of misuse appropriate ORs, conflicting reports indicate immunostimulatory and immunosuppressive activity, in that opioid users have elevated infection risk, opioids activate innate immune cells, and opioids attenuate inflammation in murine T cell-mediated autoimmunity models. The i.v. use of drugs transmits bloodborne pathogens, particularly viruses, making the study of CD8⁺ T cells timely. From a cohort of nonuser controls and methadone users, we demonstrate, via t-Stochastic Neighbor Embedding and k-means cluster analysis of surface marker expression, that chronic opioid use alters human CD8⁺ T cell subset balance, with notable decreases in T effector memory RA⁺ cells. Studying global CD8⁺ T cell populations, there were no differences in expression of OR and several markers of functionality, demonstrating the need for finer analysis. Purified CD8⁺ T cells from controls respond to opioids ex vivo by increasing cytoplasmic calcium, a novel finding for OR signal transduction, likely because of cell lineage. CD8⁺ T cells from controls exposed to μ-OR agonists ex vivo decrease expression of activation markers CD69 and CD25, although the same markers are elevated in μ-OR-treated cells from methadone users. In contrast to control cells, T cell subsets from methadone users show decreased expression of CD69 and CD25 in response to TCR stimulus. Overall, these results indicate a direct, selective role for opioids in CD8⁺ T cell immune regulation via their ability to modulate cell responses through the opioid receptors and TCRs.

History of parenting instability and lifetime suicidal behavior in people who inject drugs

Despite high rates of suicide in people who inject drugs, little is known about the risk factors for suicide related to childhood and family history in this population. We aimed to explore the relationship between the history of out-of-home care (OHC) and lifetime suicide attempts among people who inject opioids. Participants (N = 202) were current injection opioid users with at least one previous episode of opioid maintenance treatment. They were recruited into a double-blind randomized controlled trial for opioid substitution treatment. Secondary analysis of baseline data was conducted from the European Addiction Severity Index and basic demographics questionnaires. A total of 81 (40%) participants reported a history of living in OHC and 27% reported attempting suicide. Participants who reported living in OHC were more likely to report lifetime suicide attempts compared to those who did not live in OHC. History of OHC and suicidal ideation were significant risk factors for suicide attempts adjusting for depression and anxiety. Highest rates of lifetime attempts were among participants who lived in a group home, foster care, and/or psychiatric facility. Living in OHC during childhood was significantly associated with higher rates of suicide attempts in our sample. Greater efforts should be made to provide children from vulnerable families with environments where stable one-to-one relationships can be cultivated.

Factors influencing recruitment to a randomised placebo-controlled trial of oral naltrexone and extended release implant naltrexone: Qualitative study

AIMS

To understand the influences on recruitment to the Naltrexone Enhanced Addiction Treatment (NEAT) study, a randomised placebo-controlled trial of extended-release naltrexone (XR-NTX) implants for opioid use disorder (OUD), to learn lessons for the design and conduct of similar future research.

METHODS

29 face-to-face, semi-structured qualitative interviews were conducted with patients recruited to NEAT (n = 6), patients not recruited (n = 11), researchers who designed the trial (n = 5), and staff who delivered the trial (n = 7). The social marketing mix was used as a framework to guide the data analyses.

RESULTS

Dimensions of the 7Ps of the social marketing mix - product, price, place, promotion, physical environment, people, and processes all influenced recruitment to the NEAT trial. Among other things, the potential to receive a naltrexone implant (product); the provision of transport passes and shopping vouchers (price); clear verbal explanations (promotion); familiarity of the trial setting (physical environment); and approachable, friendly and informative trial delivery staff (people) positively influenced recruitment. Whereas, wanting a less medical approach to recovery (product); the perceived time, physical, and psychological costs of taking part (price); service ideological opposition to naltrexone in recovery (place); inaccessible written information (promotion); the location and nature of the trial setting (physical environment); a lack of knowledge about implants (people); and the blind allocation and potential of placebo (processes) deterred people from joining the trial.

CONCLUSIONS

Qualitative research informed by the social marketing mix as an analytical framework yielded detailed insights into understanding the factors and circumstances that influenced recruitment to the NEAT trial. Our findings have implications for the planning and implementation of future addiction trials, especially trials of extended-release formulations.

Digital Storytelling With Heroin Users in Vancouver

As the opioid crisis escalates across North America, photographers are highlighting the gravity of the situation. However, many of their images of people who use drugs are problematic and stigmatizing. This study looks at how digital storytelling (DST) was used in order to assist long-term heroin users taking part in North America's first heroin-assisted treatment program in Vancouver, BC, in amplifying and sharing their personal experiences. DST is a participatory and collaborative process designed to help people share narrative accounts of life events. A total of 10 participants took part in a 3-day DST workshop and eight individuals completed 2 to 3-minute digital stories. Participants demonstrated increased agency in terms of how they represented themselves. Their digital stories disrupt hegemonic representations of heroin users and can help educate the public and decision makers about compassionate and science-based treatments for chronic addiction. Theory, methodology, practical applications, and ethics are discussed.

Cost-effectiveness of hydromorphone for severe opioid use disorder: findings from the SALOME randomized clinical trial

BACKGROUND AND AIMS

Previous research has found diacetylmorphine, delivered under supervision, to be cost-effective in the treatment of severe opioid use disorder, but diacetylmorphine is not available in many settings. The Study to Assess Long-term Opioid Maintenance Effectiveness (SALOME) randomized controlled trial provided evidence that injectable hydromorphone is non-inferior to diacetylmorphine. The current study aimed to compare the cost-effectiveness of hydromorphone directly with diacetylmorphine and indirectly with methadone maintenance treatment.

DESIGN

A within-trial analysis was conducted using the patient level data from the 6-month, double-blind, non-inferiority SALOME trial. A life-time analysis extrapolated costs and outcomes using a decision analytical cohort model. The model incorporated data from a previous trial to include an indirect comparison to methadone maintenance.

SETTING

A supervised clinic in Vancouver, British Columbia, Canada.

PARTICIPANTS

A total of 202 long-term street opioid injectors who had at least two attempts at treatment, including one with methadone (or other substitution), were randomized to hydromorphone (n = 100) or diacetylmorphine (n = 102).

MEASUREMENTS

We measured the utilization of drugs, visits to health professionals, hospitalizations, criminal activity, mortality and quality of life. This enabled us to estimate incremental costs, quality-adjusted life years (QALYs) and cost-effectiveness ratios from a societal perspective. Sensitivity analyses considered different sources of evidence, assumptions and perspectives.

FINDINGS

The within-trial analysis found hydromorphone provided similar QALYs to diacetylmorphine [0.377, 95% confidence interval (CI) = 0.361-0.393 versus 0.375, 95% CI = 0.357-0.391], but accumulated marginally greater costs [$49 830 ($28 401-73 637) versus $34 320 ($21 780-55 998)]. The life-time analysis suggested that both diacetylmorphine and hydromorphone provide more benefits than methadone [8.4 (7.4-9.5) and 8.3 (7.2-9.5) versus 7.4 (6.5-8.3) QALYs] at lower cost [$1.01 million ($0.6-1.59 million) and $1.02 million ($0.72-1.51 million) versus $1.15 million ($0.71-1.84 million)].

CONCLUSIONS

In patients with severe opioid use disorder enrolled into the SALOME trial, injectable hydromorphone provided similar outcomes to injectable diacetylmorphine. Modelling outcomes during a patient's life-time suggested that injectable hydromorphone might provide greater benefit than methadone alone and may be cost-saving, with drug costs being offset by costs saved from reduced involvement in criminal activity.

The association between nicotine dependence and physical health among people receiving injectable diacetylmorphine or hydromorphone for the treatment of chronic opioid use disorder

INTRODUCTION

People with chronic opioid use disorder often present to treatment with individual and structural vulnerabilities and remain at risk of reporting adverse health outcomes. This risk is greatly compounded by tobacco smoking, which is highly prevalent among people with chronic opioid use disorder. Despite the known burden of tobacco smoking on health, the relationship between nicotine dependence and health has not been studied among those receiving injectable opioid agonist treatment. As such, the present study aims to explore the association between nicotine dependence and physical health among participants of the Study to Assess Longer-Term Opioid Medication Effectiveness (SALOME) at baseline and six-months.

METHODS

SALOME was a double-blind phase III clinical trial testing the non-inferiority of injectable hydromorphone to injectable diacetylmorphine for chronic opioid use disorder. Participants reporting tobacco smoking were included in a linear regression analysis of physical health at baseline (before receiving treatment) and at six-months.

RESULTS

At baseline, nicotine dependence score, lifetime history of emotional, physical, or sexual abuse and prior month safe injection site access were independently and significantly associated with physical health. At six-months nicotine dependence score was the only variable that maintained this significant and independent association with physical health.

CONCLUSIONS

Findings indicate that after six-months, the injectable treatment effectively brought equity to patients' physical health status, yet the association with nicotine dependence remained. Findings could inform whether the provision of treatment for nicotine dependence should be made a priority in settings where injectable opioid agonist treatment is delivered to achieve improvements in overall physical health in this population.

Improving recruitment to pharmacological trials for illicit opioid use: findings from a qualitative focus group study

AIM

To explore potential study participants' views on willingness to join clinical trials of pharmacological interventions for illicit opioid use to inform and improve future recruitment strategies.

DESIGN

Qualitative focus group study [six groups: oral methadone (two groups); buprenorphine tablets (two groups); injectable opioid agonist treatment (one group); and former opioid agonist treatment (one group)].

SETTINGS

Drug and alcohol services and a peer support recovery service (London, UK).

PARTICIPANTS

Forty people with experience of opioid agonist treatment for heroin dependence (26 males, 14 females; aged 33-66 years).

MEASUREMENTS

Data collection was facilitated by a topic guide that explored willingness to enrol in clinical pharmacological trials. Groups were audio-recorded and transcribed. Transcribed data were analysed inductively via Iterative Categorization.

FINDINGS

Participants' willingness to join pharmacological trials of medications for opioid dependence was affected by factors relating to study burden, study drug, study design, study population and study relationships. Participants worried that the trial drug might be worse than, or interfere with, their current treatment. They also misunderstood aspects of trial design despite the researchers' explanations.

CONCLUSIONS

Recruitment of participants for clinical trials of pharmacological interventions for illicit opioid use could be improved if researchers became better at explaining clinical trials to potential participants, dispelling misconceptions about trials and increasing trust in the research process and research establishment. A checklist of issues to consider when designing pharmacological trials for illicit opioid use is proposed.

Person-oriented research ethics: integrating relational and everyday ethics in research

Research ethics is often understood by researchers primarily through the regulatory framework reflected in the research ethics review process. This regulatory understanding does not encompass the range of ethical considerations in research, notably those associated with the relational and everyday aspects of human subject research. In order to support researchers in their effort to adopt a broader lens, this article presents a "person-oriented research ethics" approach. Five practical guideposts of person-oriented research ethics are identified, as follows: (1) respect for holistic personhood; (2) acknowledgement of lived world; (3) individualization; (4) focus on researcher-participant relationships; and (5) empowerment in decision-making. These guideposts are defined and illustrated with respect to different aspects of the research process (e.g., research design, recruitment, data collection). The person-oriented research ethics approach provides a toolkit to individual researchers, research groups, and research institutions in both biomedical and social science research wishing to expand their commitment to ethics in research.

Eligibility for heroin-assisted treatment (HAT) among people who inject opioids and are living with HIV in a Canadian setting

Objectives

A growing body of evidence supports the effectiveness of injectable diacetylmorphine (i.e., heroin) for individuals with treatment-refractory opioid use disorder. Despite this evidence, and the increasing toll of opioid-associated morbidity and mortality, it remains controversial in some settings. To investigate the possible contribution of heroin-assisted treatment (HAT) to HIV treatment-related outcomes, we sought to estimate the proportion and characteristics of HIV-positive people who inject opioids that might be eligible for HAT in Vancouver, Canada.

Methods

We used data from a prospective cohort of people living with HIV who use illicit drugs in Vancouver, Canada. Using generalized estimating equations (GEE), we assessed the longitudinal relationships between eligibility for HAT, using criteria from previous clinical trials and guidelines, with behavioural, social, and clinical characteristics.

Results

Between 2005 and 2014, 478 participants were included in these analyses, contributing 1927 person-years of observation. Of those, 94 (19.7%) met eligibility for HAT at least once during the study period. In a multivariable GEE model, after adjusting for clinical characteristics, being eligible for HAT was positively associated with homelessness, female gender, high-intensity illicit drug use, drug dealing and higher CD4 count.

Conclusions

In our study of HIV-positive people with a history of injection drug use, approximately 20% of participants were eligible for HAT at ≥ 1 follow-up period. Eligibility was linked to risk factors for sub-optimal HIV/AIDS treatment outcomes, such as homelessness and involvement in the local illicit drug trade, suggesting that scaling-up access to HAT might contribute to achieving optimal HIV treatment in this setting.

Our Life Depends on This Drug: Competence, Inequity, and Voluntary Consent in Clinical Trials on Supervised Injectable Opioid Assisted Treatment

Supervised injectable opioid assisted treament (siOAT) prescribes injectable opioids to individuals for whom other forms of addiction treatment have been ineffective. In this article, we examine arguments that opioid-dependent people should be assumed incompetent to voluntarily consent to clinical research on siOAT unless proven otherwise. We agree that concerns about competence and voluntary consent deserve careful attention in this context. But we oppose framing the issue solely as a matter of the competence of opioid-dependent people and emphasize that it should be considered in the context of inequities in access to siOAT as a medical treatment. Consequently, we suggest that bioethics literature on nonexploitation, which focuses on clinical research in low-income countries, is helpful due to locating ethical issues within systemic social conditions. Finally, we consider the implications of our argument for the ethics of clinical research on siOAT.

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

Background

To 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.

Methods

This 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.

Results

Men 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.

Conclusions

Despite 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 registration

This trial is registered with ClinicalTrials.gov (NCT01447212) Registered: October 4, 2011 at the following link: https://clinicaltrials.gov/ct2/show/NCT01447212.