Fatal opioid poisoning: a counterfactual model to estimate the preventive effect of treatment for opioid use disorder in England

Superiority and cost-effectiveness of monthly extended-release buprenorphine versus daily standard of care medication: a pragmatic, parallel-group, open-label, multicentre, randomised, controlled, phase 3 trial

Background

Daily methadone maintenance or buprenorphine treatment is the standard-of-care (SoC) medication for opioid use disorder (OUD). Subcutaneously injected, extended-release buprenorphine (BUP-XR) may be more effective-but there has been no superiority evaluation.

Methods

This pragmatic, parallel-group, open-label, multi-centre, effectiveness superiority randomised, controlled, phase 3 trial was conducted at five National Health Service community-based treatment clinics in England and Scotland. Participants (adults aged ≥ 18 years; all meeting DSM-5 diagnostic criteria for moderate or severe OUD at admission to their current maintenance treatment episode) were randomly assigned (1:1) to receive continued daily SoC (liquid methadone (usual dose range: 60-120 mg) or sublingual/transmucosal buprenorphine (usual dose range: 8-24 mg) for 24 weeks; or monthly BUP-XR (Sublocade;® two injections of 300 mg, then four maintenance injections of 100 mg or 300 mg, with maintenance dose selected by response and preference) for 24 weeks. In the intent-to-treat population (senior statistician blinded to blinded to treatment group allocation), and with a seven-day grace period after randomisation, the primary endpoint was the count of days abstinent from non-medical opioids between days 8-168 (i.e., weeks 2-24; range: 0-161 days). Safety was reported for the intention-to- treat population. Adopting a broad societal perspective inclusive of criminal justice, NHS and personal social service costs, a trial-based cost-utility analysis estimated the Incremental Cost-effectiveness Ratio (ICER) per quality-adjusted life year (QALY) of BUP-XR versus SoC at the National Institute for Health and Care Excellence threshold. The study was registered EudraCT (2018-004460-63) and ClinicalTrials.gov (NCT05164549), and is completed.

Findings

Between Aug 9, 2019 and Nov 2, 2021, 314 participants were randomly allocated to receive SoC (n = 156) or BUP-XR (n = 158). Participants were abstinent from opioids for an adjusted mean of 104.37 days (standard error [SE] 9.89; range: 0-161 days) in the SoC group and an adjusted mean of 123.43 days (SE 4.76; range: 24-161 days) in the BUP-XR group (adjusted incident rate ratio [IRR] 1.18, 95% confidence interval [CI] 1.05-1.33; p-value 0.004). The incidence of any adverse event was higher in the BUP-XR group than the SoC group (128 [81.0%] of 158 participants versus 67 [42.9%] of 156 participants, respectively-most commonly rapidly-resolving (mild-moderate range) pain from drug administration in the BUP-XR group (121 [26.9%] of 450 adverse events). There were 11 serious adverse events (7.0%) in the 158 participants in the BUP-XR group, and 18 serious adverse events (11.5%) in the 156 participants in the SoC group-none judged to be related to study treatment. The BUP-XR treatment group had a mean incremental cost of £1033 (95% central range [CR] -1189 to 3225) and was associated with a mean incremental QALY of 0.02 (95% CR 0.00-0.05), and an ICER of £47,540 (0.37 probability of being cost-effective at the £30,000/QALY gained willingness-to-pay threshold). However, BUP-XR dominated the SoC among participants who were rated more severe at study baseline, and among participants in maintenance treatment for more that 28 days at study enrolment.

Interpretation

Evaluated against the daily oral SoC, monthly BUP-XR is clinically superior, delivering greater abstinence from opioids, and with a comparable safety profile. BUP-XR was not cost-effective in a base case cost-utility analysis using the societal perspective, but it was more effective and less costly (dominant) among participants with more severe OUD, or those whose current treatment episode was longer than 28 days. Further trials are needed to evaluate if BUP-XR is associated with better clinical and health economic outcomes over the longer term.

Funding

Indivior.

Patients' perceptions of self-administered dosing to opioid agonist treatment and other changes during the COVID-19 pandemic: a qualitative study

OBJECTIVES

During the COVID-19 pandemic, addiction treatment services received official guidance asking them to limit face-to-face contact with patients and to prescribe opioid agonist treatment (OAT) medication flexibly. With the aim for most patients to receive take-home supplies for self-administration rather than attendance for observed daily dosing.

DESIGN

This was a theory-driven, clinically applied qualitative study, with data for thematic analysis collected by semi-structured, audio-recorded, telephone interviews.

PARTICIPANTS

Twenty-seven adults (aged ≥18 years) enrolled in sublingual (tablet) buprenorphine and oral (liquid) methadone OAT.

SETTING

Community addictions centre in the London Borough of Lambeth operated by South London and Maudsley NHS Trust.

RESULTS

Three major themes were identified: (1) dissatisfaction and perceived stigma with OAT medication dispensing arrangements before the pandemic; (2) positive adaptations in response to COVID-19 by services; (3) participants recommended that, according to preference and evidence of adherence, OAT should be personalised to offer increasing medication supplies for self-administration from as early as 7 days after commencement of maintenance prescribing.

CONCLUSIONS

In an applied qualitative study of patients enrolled in OAT during the COVID-19 pandemic, participants endorsed their opportunity to take medication themselves at home and with virtual addiction support. Most patients described a preference for self-administration with increased dispensing supplies, from as early as 7 days into maintenance treatment, if they could demonstrate adherence to their prescription.

Experience and response to a randomised controlled trial of extended-release injectable buprenorphine versus sublingual tablet buprenorphine and oral liquid methadone for opioid use disorder: protocol for a mixed-methods evaluation

INTRODUCTION

Opioid use disorder (OUD) is a debilitating and persistent disorder. The standard-of-care treatment is daily maintenance dosing of sublingual buprenorphine (BUP-SL) or oral methadone (MET). Monthly, extended-release, subcutaneous injectable buprenorphine (BUP-XR) has been developed to enhance treatment effectiveness. This study aims to investigate the experiences of participants who have been offered BUP-XR (evaluation 1), health-related quality-of-life among participants who have opted to receive BUP-XR longer term (evaluation 2) and the experiences of participants allocated to receive BUP-XR or BUP-SL or MET with the offer of adjunctive personalised psychosocial intervention (evaluation 3).

METHODS AND ANALYSIS

Three qualitative-quantitative (mixed-methods) evaluations embedded in a five-centre, head-to-head, randomised controlled trial of BUP-XR versus BUP-SL and MET in the UK. Evaluation 1 is a four-centre interview anchored on an OUD-related topic guide and conducted after the 24-week trial endpoint. Evaluation 2 is a two-centre interview anchored on medications for opioid use disorder-specific quality-of-life topic guide conducted among participants after 12-24 months. Evaluation 3: single-centre interview after the 24-week trial endpoint. All evaluations include selected trial clinical measures, with evaluation 2 incorporating additional questionnaires. Target participant recruitment for evaluations 1 and 2 is 15 participants per centre (n=60 and n=30, respectively). Recruitment for evaluation 3 is 15 participants per treatment arm (n=30). Each evaluation will be underpinned by theory, drawing on constructs from the behavioural model for health service use or the health-related quality-of-life model. Qualitative data analysis will be by iterative categorisation.

ETHICS AND DISSEMINATION

Study protocol, consent materials and questionnaires were approved by the London-Brighton and Sussex research ethics committee (reference: 19/LO/0483) and the Health Research Authority (IRAS project number 255522). Participants will be provided with information sheets and informed written consent will be obtained for each evaluation. Study findings will be disseminated through peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

2018-004460-63.

Extended-release pharmacotherapy for opioid use disorder (EXPO): protocol for an open-label randomised controlled trial of the effectiveness and cost-effectiveness of injectable buprenorphine versus sublingual tablet buprenorphine and oral liquid methadone

Background

Sublingual tablet buprenorphine (BUP-SL) and oral liquid methadone (MET) are the daily, standard-of-care (SOC) opioid agonist treatment medications for opioid use disorder (OUD). A sizable proportion of the OUD treatment population is not exposed to sufficient treatment to attain the desired clinical benefit. Two promising therapeutic technologies address this deficit: long-acting injectable buprenorphine and personalised psychosocial interventions (PSI). This study will determine (A) the effectiveness and cost-effectiveness — monthly injectable, extended-release (BUP-XR) in a head-to-head comparison with BUP-SL and MET, and (B) the effectiveness of BUP-XR with adjunctive PSI versus BUP-SL and MET with PSI. Safety, retention, craving, substance use, quality-adjusted life years, social functioning, and subjective recovery from OUD will be also evaluated.

Methods

This is a pragmatic, multi-centre, open-label, parallel-group, superiority RCT, with a qualitative (mixed-methods) evaluation. The study population is adults. The setting is five National Health Service community treatment centres in England and Scotland. At each centre, participants will be randomly allocated (1:1) to BUP-XR or SOC. At the London study co-ordinating centre, there will also be allocation of participants to BUP-XR with PSI or SOC with PSI. With 24 weeks of study treatment, the primary outcome is days of abstinence from non-medical opioids during study weeks 2–24 combined with up to 12 urine drug screen tests for opioids. For 90% power (alpha, 5%; 15% inflation for attrition), 304 participants are needed for the BUP-XR versus SOC comparison. With the same planning parameters, 300 participants are needed for the BUP-XR and PSI versus SOC and PSI comparison. Statistical and health economic analysis plans will be published before data-lock on the Open Science Framework. Findings will be reported in accordance with the Consolidated Standards of Reporting Trials and Consolidated Health Economic Evaluation Reporting Standards.

Discussion

This pragmatic randomised controlled trial is the first evaluation of injectable BUP-XR versus the SOC medications BUP-SL and MET, with personalised PSI. If there is evidence for the superiority of BUP-XR over SOC medication, study findings will have substantial implications for OUD clinical practice and treatment policy in the UK and elsewhere.

Trial registration

EU Clinical Trials register 2018-004460-63.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06595-0.

Opioid overdose deaths and the expansion of opioid agonist treatment: a population-based prospective cohort study

BACKGROUND AND AIM

Effective policies to reduce drug-related overdoses remain a public health priority. We aimed to estimate the causal effects of a national opioid agonist treatment (OAT) program on population level drug fatalities.

DESIGN

Population-based prospective cohort study exploiting supply driven variation in treatment uptake across cohort-age groups generated by the introduction and scale-up of a national OAT program. A Poisson difference-in-differences model with an intention-to-treat design was used to assess how treatment uptake altered the age profile of risks and infer treatment effects on drug fatalities.

SETTING

Norway, from 1996 through 2016.

CASES

The data include a total of 5634 drug-related overdose deaths and cover the introduction of the Norwegian OAT program in 1998 and its initial growth period, reaching 12 286 ever-treated recipients by 2016.

MEASUREMENTS

Fatal opioid-related overdoses were defined as deaths with a primary cause assigned an International Classification of Diseases 10th Revision (ICD-10) code F11, or X42, X44, X62 or X64 in combination with T40.0-T40.4. Other non-opioid related fatal overdoses were defined by a primary cause registered as F12, F14, F15, F16 or F19, or X42, X44, X62 or 64 in combination with T40.5-T40.9.

FINDINGS

An additional 887 deaths (95% credibility interval [CI] = 265-1563) would have been expected in the absence of OAT, which implies one death avoided per 111 (95% CI = 61-342) treatment-exposed person-years. At scale, the program reduced annual overdose mortality by 27% in 2016 (95% CI = 10%-41%) relative to a no-OAT counterfactual, corresponding to 99 fewer expected fatal overdoses (95% CI = 28-180) in 2016. Analysing fatal opioid-related and other drug overdoses separately found similar numbers for avoided opioid-related fatalities (921, with 95% CI = 373-1526) and no treatment effects on non-opioid related fatalities (-38, with 95% CI = -193-154).

CONCLUSION

The introduction and rapid scale-up of a national opioid agonist treatment program in Norway was associated with substantial and plausibly causal reductions in drug fatalities.

Effectiveness of incentivised adherence and abstinence monitoring in buprenorphine maintenance: a pragmatic, randomised controlled trial

BACKGROUND AND AIM

Buprenorphine (BUP) maintenance treatment for opioid use disorder (OUD) begins with supervised daily dosing. We estimated the clinical effectiveness of a novel incentivised medication adherence and abstinence monitoring protocol in BUP maintenance to enable contingent access to increasing take-home medication supplies.

DESIGN

Two-arm, single-centre, pragmatic, randomised controlled trial of outpatient BUP maintenance, with during-treatment follow-ups at 4 weeks, 8 weeks, 12 weeks and 16 weeks.

SETTING

Inpatient and outpatient addictions treatment centre in the United Arab Emirates.

PARTICIPANTS

Adults with OUD, voluntarily seeking treatment.

INTERVENTIONS

The experimental condition was 16 weeks BUP maintenance with incentivised adherence and abstinence monitoring (I-AAM) giving contingent access to 7-day, then 14-day, then 21-day and 28-day medication supply. The control, treatment-as-usual (TAU) was 16 weeks BUP maintenance, with contingent access to 7-day then 14-day supply.

MEASUREMENTS

The primary outcome was number of negative urine drug screens (UDS) for opioids, with non-attendance or otherwise missed UDS, imputed as positive for opioids. The secondary outcome was retention in treatment (continuous enrolment to the 16-week endpoint).

FINDINGS

Of 182 patients screened, 171 were enrolled and 141 were randomly assigned to I-AAM (70 [49.6%]) and to TAU (71 [50.4%]. Follow-up rates at 4 weeks, 8 weeks, 12 weeks and 16 weeks were 91.4%, 85.7%, 71.0%, 60.0% respectively in I-AAM and 84.5%, 83.1%, 69.0%, 56.3% in TAU. By intention-to-treat, the absolute difference in percentage negative UDS for opioids was 76.7% (SD = 25.0%) in I-AAM versus 63.5% (SD = 34.7%) in TAU (mean difference = 13.3%; 95% CI = 3.2%-23.3%; Cohen's d = 0.44; 95% CI = 0.10-0.87). In I-AAM, 40 participants (57.1%) were retained versus 33 (46.4%) in TAU (odds ratio = 1.54; 95% CI = 0.79-2.98).

CONCLUSIONS

Buprenorphine maintenance with incentivised therapeutic drug monitoring to enable contingent access to increasing take-home medication supplies increased abstinence from opioids compared with buprenorphine maintenance treatment-as-usual, but it did not appear to increase treatment retention.

Drug fatalities and treatment fatalism: Complicating the ageing cohort theory

Deaths related to drug 'misuse' remain at an all-time high in the United Kingdom (UK). Older heroin consumers are particularly at risk, with the highest rates of deaths among people aged 40-49 and the steepest rises in the over-fifty age bracket. Accordingly, a popular theory for the UK's increase in drug-related deaths, made by the government, and propelled in the media, is that there is an ageing cohort of heroin users with age-related health complications predisposing them to an overdose. However, drawing on in-depth interviews with those people deemed to be most at risk, this article works to complicate this theory, with participants citing a shift in (a) experience and responsibility, (b) route of administration, (c) desired effects, (d) acceptance of their drug use and 'user' status and (e) valuing health. Disrupting age as a given risk factor, this article turns attention away from the individual and these 'natural' processes to what participants describe as a singular, punitive, and inflexible treatment system and its intersecting structures. Approaching life and death as a matter of sociomaterial 'mattering', this article rethinks a reductionist, causal link between age and drug-related death with a treatment despondency and fatalism that could prove fatal.

Explaining the Differences in Opioid Overdose Deaths between Scotland and England/Wales: Implications for European Opioid Policies

BACKGROUNDS

Between 2009 and 2018, the number of opioid-related deaths (ORDs) in Scotland showed a dramatic increase, whereas in England and Wales, a much lower increase in ORD was seen. This regional difference is remarkable, and the situation in Scotland is worrisome. Therefore, it is important to identify the drivers of ORD in Scotland.

METHODS

A systematic literature review according to PRISMA guidelines was conducted to identify peer-reviewed studies about key drivers for the observed differences in ORDs between Scotland and England/Wales. In addition, non-peer-reviewed reports on nationwide statistical data were retrieved via Google and Google Scholar and analysed to quantify differences in ORD drivers between Scotland and England/Wales.

RESULTS

The systematic review identified some important drivers of ORD, but none of these studies provided direct or indirect comparisons of ORD drivers in Scotland and England/Wales. However, the reports with nationwide statistical data showed important differences in ORD drivers between Scotland and England/Wales, including a higher prevalence of people using opioids in a problematic way (PUOP), more polydrug use in people using drugs in a problematic way (PUDP), a higher age of PUDP, and lower treatment coverage and efficacy of PUDP in Scotland compared to England/Wales, but no regional differences in injecting drug use, incarceration/prison release without treatment, and social deprivation in PUDP.

CONCLUSION

It is concluded that the opioid crisis in Scotland is best explained by a combination of drivers, consisting of a higher population involvement in (problematic) opioid use (notably methadone), relatively more polydrug use (notably benzodiazepines and gabapentinoids), a steeper ageing of the PUOP population in the past 2 decades, and lower treatment coverage and efficacy in Scotland compared to England/Wales. The findings have important consequences for strategies to handle the opioid crisis in Scotland.

Is disinvestment from alcohol and drug treatment services associated with treatment access, completions and related harm? An analysis of English expenditure and outcomes data

INTRODUCTION

The positive impact of substance use treatment is well-evidenced but there has been substantial disinvestment from publicly funded treatment services in England since 2013/2014. This paper examines whether this disinvestment from adult alcohol and drug treatment provision was associated with changes in treatment and health outcomes, including: treatment access, successful completions from treatment, alcohol-specific hospital admissions, alcohol-specific mortality and drug-related deaths.

METHODS

Annual administrative data from 2013/2014 to 2018/2019 was matched at local government level and multi-level time series analysis using linear mixed-effect modelling conducted for 151 upper-tier local authorities in England.

RESULTS

Between 2013/2014 and 2018/2019, £212.2 million was disinvested from alcohol and drug treatment services, representing a 27% decrease. Concurrently, 11% fewer people accessed, and 21% fewer successfully completed, treatment. On average, controlling for other potential explanatory factors, a £10 000 disinvestment from alcohol and drug treatment services was associated with reductions in all treatment outcomes, including 0.3 fewer adults in treatment (95% confidence interval 0.16-0.45) and 0.21 fewer adults successfully completing treatment (95% % confidence interval 0.12-0.29). A £10 000 disinvestment from alcohol treatment was not significantly associated with changes in alcohol-specific hospital admissions or mortality, nor was disinvestment from drug treatment associated with the rate of drug-related deaths.

DISCUSSION AND CONCLUSIONS

Local authority spending cuts to alcohol and drug treatment services in England were associated with fewer people accessing and successfully completing alcohol and drug treatment but were not associated with changes in related hospital admissions and deaths.

Scotland's 2009-2015 methadone-prescription cohort: Quintiles for daily dose of prescribed methadone and risk of methadone-specific death

AIMS

As methadone clients age, their drug-related death (DRD) risks increase, more than doubling at 45+ years for methadone-specific DRDs.

METHODS

Using Community Health Index (CHI) numbers, mortality to 31 December 2015 was ascertained for 36 347 methadone-prescription clients in Scotland during 2009-2015. Cohort entry, quantity of prescribed methadone and daily dose (actual or recovered by effective, simple rules) were defined by clients' first CHI-identified methadone prescription after 30 June 2009 and used in proportional hazards analysis. As custodian of death records, National Records of Scotland identified non-DRDs from DRDs. Methadone-specific DRD means methadone was implicated but neither heroin nor buprenorphine.

RESULTS

The cohort's 192 928 person-years included 1857 non-DRDs and 1323 DRDs (42%), 546 of which were methadone specific. Actual/recovered daily dose was available for 26 533 (73%) clients who experienced 420 methadone-specific DRDs. Top quintile for daily dose at first CHI-identified methadone prescription was >90 mg. Age 45+ years at cohort-entry (hazard ratio vs 25-34 years: 3.1, 95% confidence interval: 2.4-4.2), top quintile for baseline daily dose of prescribed methadone (vs 50-70 mg: 1.9, 1.1-3.1) and being female (1.3, 1.0-1.6) significantly increased clients' risk of methadone-specific DRD.

CONCLUSION

Extra care is needed when methadone daily dose exceeds 90 mg. Females' higher risk for methadone-specific DRD is new and needs validation. Further analyses of prescribed daily dose linked to mortality for large cohorts of methadone clients are needed internationally, together with greater pharmacodynamic and pharmacokinetic understanding of methadone by age and sex. Balancing age-related risks is challenging for prescribers who manage chronic opiate dependency against additional uncertainty about the nature, strength and pharmacological characteristics of drugs from illegal markets.

Concomitant drugs with buprenorphine user deaths

BACKGROUND

Buprenorphine is abused in several countries notwithstanding its benefits as an analgesic and as an opioid agonist treatment medication. Benzodiazepines and alcohol have previously been associated with buprenorphine toxicity. This study elucidates the role of emerging concomitant drugs in different groups of buprenorphine user deaths.

METHODS

All cases in the Finnish national post-mortem toxicology database from 2016-2019 in which buprenorphine or norbuprenorphine was a laboratory finding in any post-mortem specimen and age at death of 15-64 years were investigated for cause and manner of death, concurrent drug and alcohol findings, age, and gender.

RESULTS

There were 792 deaths with a buprenorphine finding, of which buprenorphine was implicated in poisoning without other opioids in 271 cases (34 %). In this group of buprenorphine poisoning deaths, concomitant benzodiazepines were found in 94 % (clonazepam 53 %), illicit drugs in 63 %, gabapentinoids in 50 % (pregabalin 41 %), alcohol in 41 %, antidepressants in 32 %, and antipsychotics in 28 % of cases; only three deaths showed no benzodiazepines, alcohol, or gabapentinoids. Polydrug use was common regardless of the cause of death. In the age group 15 to 24 years, concomitant use of benzodiazepines and illicit drugs, and buprenorphine poisoning were more prevalent than in the age group 25-64 years.

CONCLUSIONS

The unprecedentedly high concomitant use of benzodiazepines in buprenorphine user deaths obscures other possible pharmacological risk factors for buprenorphine poisoning that could be relevant for prevention. Higher mortality in the younger age group suggests particularly unsafe drug use patterns that should be addressed.

National administrative record linkage between specialist community drug and alcohol treatment data (the National Drug Treatment Monitoring System (NDTMS)) and inpatient hospitalisation data (Hospital Episode Statistics (HES)) in England: design, method and evaluation

OBJECTIVES

The creation and evaluation of a national record linkage between substance misuse treatment, and inpatient hospitalisation data in England.

DESIGN

A deterministic record linkage using personal identifiers to link the National Drug Treatment Monitoring System (NDTMS) curated by Public Health England (PHE), and Hospital Episode Statistics (HES) Admitted Patient Care curated by National Health Service (NHS) Digital.

SETTING AND PARTICIPANTS

Adults accessing substance misuse treatment in England between 1 April 2018 and 31 March 2019 (n=268 251) were linked to inpatient hospitalisation records available since 1 April 1997.

OUTCOME MEASURES

Using a gold-standard subset, linked using NHS number, we report the overall linkage sensitivity and precision. Predictors for linkage error were identified, and inverse probability weighting was used to interrogate any potential impact on the analysis of length of hospital stay.

RESULTS

79.7% (n=213 814) people were linked to at least one HES record, with an estimated overall sensitivity of between 82.5% and 83.3%, and a precision of between 90.3% and 96.4%. Individuals were more likely to link if they were women, white and aged between 46 and 60. Linked individuals were more likely to have an average length of hospital stay ≥5 days if they were men, older, had no fixed residential address or had problematic opioid use. These associations did not change substantially after probability weighting, suggesting they were not affected by bias from linkage error.

CONCLUSIONS

Linkage between substance misuse treatment and hospitalisation records offers a powerful new tool to evaluate the impact of treatment on substance related harm in England. While linkage error can produce misleading results, linkage bias appears to have little effect on the association between substance misuse treatment and length of hospital admission. As subsequent analyses are conducted, potential biases associated with the linkage process should be considered in the interpretation of any findings.

Community pharmacists' role in preventing opioid substitution therapy-related deaths: a qualitative investigation into current UK practice

Background Opioid substitution therapy involves prescribing of medical substitutes like methadone and buprenorphine to patients who are addicted to opioids. The majority of opioid substitution therapy dispensing in the UK is done by community pharmacists and they often see the patients on daily basis. It is unknown to what extent community pharmacists implement the policy to prevent overdose in patients receiving such treatment. Objective To explore what UK community pharmacists think about their role in preventing opium substitution-related deaths, their understanding of the risks associated with this substitution therapy and their views on what else community pharmacists could do to reduce such deaths. Setting Twenty four community pharmacists from two areas in UK (Worcestershire and Bath and North East Somerset). Method  Between January and March 2013, community pharmacists providing opoin substitution therapy were interviewed in their pharmacy, using semi-structured interviews. Interpretative Phenomenology Analysis was used to analyse the data. Main outcome measure Thematically organised description of professional practice as reported by the participants against the clinical/practice guidance for opioid substitution therapy in UK. Results While participants felt their role to be essential in providing the service, they did not feel part of an integrated system. Participants’ ability to act in risk situations was affected by their knowledge, confidence in intervening in such situation, as well as the support they receive in providing the service. Conclusion Participants reported large differences in how ‘opioid substitution therapy’ services are provided in community pharmacy. Lack of knowledge among some pharmacists and lack of support in providing the service resulted in some patients at high risk not having their risks acted upon.

The impact of opiate substitution treatment on mortality risk in drug addicts: a natural experiment study

Background

Opiate substitution treatment (OST) is the main treatment for people addicted to heroin and other opioid drugs. However, there is limited information on how the delivery of this treatment affects mortality risk.

Objectives

To investigate the associations of mortality risk with periods during treatment and following cessation of treatment, medication type, co-prescription of other medication and dosing regimens during titration and detoxification. The trends with time of prescribed medication, dose and treatment duration were also explored.

Design

Prospective longitudinal observational study.

Setting

UK primary care between 1998 and 2014.

Participants

A total of 12,780 patients receiving methadone, buprenorphine or dihydrocodeine.

Main outcome measures

All-cause mortality relating to 657 deaths and drug-related poisoning relating to 113 deaths.

Data sources

Clinical Practice Research Datalink with linked information on cause of death from the Office for National Statistics.

Results

For both outcomes, the lowest mortality risk was observed after 4 weeks of treatment and the highest risk was observed in the first 4 weeks following cessation of treatment [e.g. for drug-related poisoning, incidence rate ratio (IRR) 8.15, 95% confidence interval (CI) 5.45 to 12.19]. There was evidence that the treatment period risks varied with OST medication. The largest difference in risk was for the first 4 weeks of treatment for both outcomes, with patients on buprenorphine being at lower risk than those on methadone (e.g. for drug-related poisoning, IRR 0.08, 95% CI 0.01 to 0.48). The co-prescription of benzodiazepines was associated with linearly increasing the risk of drug-related deaths by dose (IRR 2.02, 95% CI 1.66 to 2.47), whereas z-drugs (zolpidem, zopiclone and zaleplon) were associated with increased risk of both all-cause (IRR 1.83, 95% CI 1.59 to 2.12) and drug-related (IRR 3.31, 95% CI 2.45 to 4.47) mortality. There was weak evidence that higher initial and final doses were associated with increased all-cause mortality risk. In the first 4 weeks of treatment, the risk increased by 4% for each 5-mg increment in methadone dose (1-mg increase in buprenorphine) (hazard ratio 1.04, 95% CI 1.00 to 1.09). In the first 4 weeks after treatment ceased, a similar increment in final dose increased the risk by 3% (hazard ratio 1.03, 95% CI 0.99 to 1.07). There were too few deaths to evaluate the effects on drug-related poisoning. The proportion of OST patients receiving buprenorphine increased between 1998 and 2006. Median treatment duration was consistently shorter for buprenorphine than for methadone for each year studied (overall median duration of 48 and 106 days, respectively).

Limitations

As this was an observational study, the possibility remains of bias from unmeasured factors, which covariate adjustment and inverse probability weighting can eliminate only partially.

Conclusions

Using buprenorphine as an alternative to methadone may not reduce mortality overall despite resulting in lower IRRs from shorter treatment duration. Clinical guidance needs to consider strengthening warnings about the co-prescription of a range of drugs for OST patients.

Future work

Our analyses need to be replicated using other clinical data sets in the UK and in other countries. New interventions and trials are required to investigate improving the retention of OST patients in primary care.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Change in alcohol and other drug use during five years of continuous opioid substitution treatment

BACKGROUND

English national prospective, observational cohort study of patients continuously enrolled for five years in opioid substitution treatment (OST) with oral methadone and sublingual buprenorphine. This is a secondary outcome analysis of change in use of alcohol and other drug use (AOD) following identification of heroin use trajectories during OST.

METHODS

All adults admitted to community OST in 2008/09 and enrolled to 2013/14 (n = 7717). Data from 11 sequential, six-monthly clinical reviews were used to identify heroin and AOD use trajectories by multi-level Latent Class Growth Analysis. OST outcome in the sixth and seventh year was 'successful completion and no re-presentation' (SCNR) to structured treatment and was assessed using multi-level logistic regression.

RESULTS

With 'rapid decreasing' heroin use trajectory as referent, 'continued high-level' heroin use predicted 'continued high-level' crack cocaine use (relative risk ratio [RRR] 58.7; 95% confidence interval [CI] 34.2-100.5),'continued high-level' alcohol use (RRR 1.2; 95% CI 1.0-1.5), 'increasing' unspecified drug use (RRR 1.7; 95% CI 1.4-2.1) and less 'high and increasing' cannabis use (RRR 0.5; 95% CI 0.4-0.6). 'Increasing' crack use was negatively associated with SCNR outcome for the 'decreasing then increasing' and 'gradual decreasing' heroin use groups (adjusted odds ratio [AOR] 0.5; 95% CI 0.3-0.9 and AOR 0.2; 95% CI 0.1-0.7, respectively).

CONCLUSIONS

Continued high-level heroin use non-response during long-term OST is associated with high-level crack cocaine and alcohol use, increasing unspecified drug use, but less high and increasing cannabis use. Increasing use of crack cocaine is negatively associated with the likelihood that long-term OST is completed successfully.

The impact of buprenorphine and methadone on mortality: a primary care cohort study in the United Kingdom

AIMS

To estimate whether opioid substitution treatment (OST) with buprenorphine or methadone is associated with a greater reduction in the risk of all-cause mortality (ACM) and opioid drug-related poisoning (DRP) mortality.

DESIGN

Cohort study with linkage between clinical records from Clinical Practice Research Datalink and mortality register.

SETTING

UK primary care.

PARTICIPANTS

A total of 11 033 opioid-dependent patients who received OST from 1998 to 2014, followed-up for 30 410 person-years.

MEASUREMENTS

Exposure to methadone (17 373, 61%) OST episodes or buprenorphine (9173, 39%) OST episodes. ACM was available for all patients; information on cause of death and DRP was available for 5935 patients (54%) followed-up for 16 363 person-years. Poisson regression modelled mortality by treatment period with an interaction between OST type and treatment period (first 4 weeks on OST, rest of time off OST, first 4 weeks off OST, rest of time out of OST censored at 12 months) to test whether ACM or DRP differed between methadone and buprenorphine. Inverse probability weights were included to adjust for confounding and balance characteristics of patients prescribed methadone or buprenorphine.

FINDINGS

ACM and DRP rates were 1.93 and 0.53 per 100 person-years, respectively. DRP was elevated during the first 4 weeks of OST [incidence rate ratio (IRR) = 1.93 95% confidence interval (CI) = 0.97-3.82], the first 4 weeks off OST (IRR = 8.15, 95% CI = 5.45-12.19) and the rest of time out of OST (IRR = 2.13, 95% CI = 1.47-3.09) compared with mortality risk from 4 weeks to end of treatment. Patients on buprenorphine compared with methadone had lower ACM rates in each treatment period. After adjustment, there was evidence of a lower DRP risk for patients on buprenorphine compared with methadone at treatment initiation (IRR = 0.08, 95% CI = 0.01-0.48) and rest of time on treatment (IRR = 0.37, 95% CI = 0.17-0.79). Treatment duration (mean and median) was shorter on buprenorphine than methadone (173 and 40 versus 363 and 111, respectively). Model estimates suggest that there was a low probability that methadone or buprenorphine reduced the number of DRP in the population: 28 and 21%, respectively.

CONCLUSIONS

In UK general medical practice, opioid substitution treatment with buprenorphine is associated with a lower risk of all-cause and drug-related poisoning mortality than methadone. In the population, buprenorphine is unlikely to give greater overall protection because of the relatively shorter duration of treatment.

Continuous opioid substitution treatment over five years: Heroin use trajectories and outcomes

BACKGROUND

This is the first national study in England of continuous long-term opioid substitution treatment (OST).

METHODS

All adults were admitted to community OST for opioid use disorder (OUD) in 2008/09 with continuous enrolment to 2013/14 (n = 7719). Heroin use trajectories were identified by multilevel Latent Class Growth Analysis. In Year 6 and 7 of follow-up, the outcome measure (analysed by multilevel, multivariable logistic regression) was 'successful completion and no re-presentation' (SCNR) to community treatment within six months.

RESULTS

Five heroin use trajectory classes were identified: 'gradual decreasing' (20.9%), 'decreasing then increasing' (21.7%), 'continued low-level' (17.0%), 'rapid decreasing' (25.6%), and 'continued high-level' (14.8%). At the end of Year 7, 4616 people (60.3%) remained in OST. Of those discharged, 28.8% achieved the SCNR follow-up outcome. SCNR was more likely in the 'gradual decreasing' (adjusted odds ratio [AOR] 2.40; 95% confidence interval [CI] 1.77-3.26), 'continued low-level' (AOR 2.46; CI 1.78-3.40), and 'rapid decreasing' (AOR 3.40; CI 2.43-4.37) classes relative to the 'continued high-level' class. SCNR was more likely among patients employed at admission (AOR 1.45; 95% CI 1.15-1.83) and those receiving adjunctive psychosocial interventions (AOR 1.44; 95% CI 1.03 to 2.02).

CONCLUSIONS

Among English patients in OST for 5 years, heroin use trajectories were clearly delineated with a gradient of response on the study outcome. Successful completion and no re-presentation was achieved by 28.8% of discharged patients. The rapid decreasing trajectory had the greatest likelihood of positive outcome. Adjunctive psychosocial intervention during OST was associated with positive outcome.

Effectiveness of community psychosocial and pharmacological treatments for alcohol use disorder: A national observational cohort study in England

BACKGROUND

This was a national English observational cohort study using administrative data to estimate the effectiveness of community pharmacological and psychosocial treatment for alcohol use disorder (AUD).

METHODS

All adults commencing AUD treatment in the community reported to the National Drug Treatment Monitoring System (April 1 2014-March 31 2015; N = 52,499). Past 28-day admission drinking pattern included drinks per drinking day (DDD): 0 ('Abstinent'), 1-15 ('Low-High'), 16-30 ('High-Extreme') and over 30 DDD ('Extreme'). The primary outcome was successful completion of treatment within 12 months of commencement with no re-presentation (SCNR) in the subsequent six months, analysed by multi-level, mixed effects, multivariable logistic regression.

RESULTS

The majority reported DDD in the 'Low-High' (n = 17,698, 34%) and 'High-Extreme' (n = 21,383, 41%) range. Smaller proportions were categorised 'Extreme' (n = 7759, 15%) and 'Abstinent' (n = 5661, 11%). Three-fifths (58%) achieved SCNR. Predictors of SCNR were older age, black/minority ethnic group, employment, criminal justice system referral, and longer treatment exposure. Predictors of negative outcome were AUD treatment history, lower socio-economic status, housing problems, and 'Extreme' drinking at admission. In addition to psychosocial interventions, pharmacological interventions and recovery support increased the likelihood of SCNR. Pharmacological treatment was only beneficial for the 'Low-High' groups with recovery support.

CONCLUSIONS

Over half of all patients admitted for community AUD treatment in England are reported to successfully complete treatment within 12 months and are not re-admitted for further treatment in the following 6 months. Study findings underscore efforts to tailor AUD treatment to the severity of alcohol consumption and using recovery support.

Does exposure to opioid substitution treatment in prison reduce the risk of death after release? A national prospective observational study in England

BACKGROUND AND AIMS

People with opioid use disorder (OUD) in prison face an acute risk of death after release. We estimated whether prison-based opioid substitution treatment (OST) reduces this risk.

DESIGN

Prospective observational cohort study using prison health care, national community drug misuse treatment and deaths registers.

SETTING

Recruitment at 39 adult prisons in England (32 male; seven female) accounting for 95% of OST treatment in England during study planning.

PARTICIPANTS

Adult prisoners diagnosed with OUD (recruited: September 2010-August 2013; first release: September 2010; last release: October 2014; follow-up to February 2016; n = 15 141 in the risk set).

INTERVENTION AND COMPARATOR

At release, participants were classified as OST exposed (n = 8645) or OST unexposed (n = 6496). The OST unexposed group did not receive OST, or had been withdrawn, or had a low dose.

MEASUREMENTS

Primary outcome: all-cause mortality (ACM) in the first 4 weeks.

SECONDARY OUTCOMES

drug-related poisoning (DRP) deaths in the first 4 weeks; ACM and DRP mortality after 4 weeks to 1 year; admission to community drug misuse treatment in the first 4 weeks. Unadjusted and adjusted Cox regression models (covariates: sex, age, drug injecting, problem alcohol use, use of benzodiazepines, cocaine, prison transfer and admission to community treatment), tested difference in mortality rates and community treatment uptake.

FINDINGS

During the first 4 weeks after prison release there were 24 ACM deaths: six in the OST exposed group and 18 in the OST unexposed group [mortality rate 0.93 per 100 person-years (py) versus 3.67 per 100 py; hazard ratio (HR) = 0.25; 95% confidence interval (CI) = 0.10-0.64]. There were 18 DRP deaths: OST exposed group mortality rate 0.47 per 100 py versus 3.06 per 100 py in the OST unexposed group (HR = 0.15; 95% CI = 0.04-0.53). There was no group difference in mortality risk after the first month. The OST exposed group was more likely to enter drug misuse treatment in the first month post-release (odds ratio 2.47, 95% CI = 2.31-2.65). The OST mortality protective effect on ACM and DRP mortality risk was not attenuated by demographic, overdose risk factors, prison transfer or community treatment (fully adjusted HR = 0.25; 95% CI = 0.09-0.64 and HR = 0.15; 95% CI = 0.04-0.52, respectively).

CONCLUSIONS

In an English national study, prison-based opioid substitution therapy was associated with a 75% reduction in all-cause mortality and an 85% reduction in fatal drug-related poisoning in the first month after release.

Effectiveness of treatment for opioid use disorder: A national, five-year, prospective, observational study in England

BACKGROUND

This the first 5-year effectiveness study of publicly funded treatment for opioid use disorder (OUD) in England.

METHODS

All adults initiating treatment in 2008/09 in all 149 local treatment systems reporting to the National Drug Treatment Monitoring System (n=54,347). Admission polydrug use sub-populations were identified by Latent Class Analysis. The treatment outcome measure was 'successful completion and no re-presentation within six months' (SCNR) analysed by multilevel, multivariable logistic regression and funnel plots to contrast outcome by treatment system.

RESULTS

SCNR was achieved by 21.9%. Heroin and crack cocaine users were significantly less likely to achieve this outcome than patients who used heroin only (adjusted odds ratio [AOR] 0.90; 95% confidence interval [CI] 0.85-0.95). Older patients (AOR 1.09; CI 1.07-1.11), those employed (AOR 1.27; CI 1.18-1.37) and those enrolled for longer treatment were more likely to achieve the outcome measure. After risk adjustment, the local treatment systems that achieved substantially better outcome performance (14/149) had a lower rate of opiate prevalence in the local population at time of study initiation (incidence rate difference [IRD] 4.1; CI 4.0-4.2), fewer criminal offences per thousand (IRD 28.5; CI 28.1-28.8) and lower drug-related deaths per million (IRD 5.9; CI 5.9-5.9).

CONCLUSIONS

In an English national study, one fifth of patients successful completed treatment for OUD and did not present for further treatment within six months. Longer time in treatment increases the probability of achieving and maintaining clinical benefit from treatment. After risk-adjustment, an important minority of treatment systems achieve substantially better outcome performance.

Risk-factors for methadone-specific deaths in Scotland's methadone-prescription clients between 2009 and 2013

AIM

To quantify gender, age-group and quantity of methadone prescribed as risk factors for drugs-related deaths (DRDs), and for methadone-specific DRDs, in Scotland's methadone-prescription clients.

DESIGN

Linkage to death-records for Scotland's methadone-clients with one or more Community Health Index (CHI)-identified methadone prescriptions during July 2009 to June 2013.

SETTING

Scotland's Prescribing Information System and National Records of Scotland.

MEASUREMENTS

Covariates defined at first CHI-identified methadone prescription, and person-years at-risk (pys) thereafter until the earlier of death-date or 31 December 2013. Methadone-specific DRDs were defined as: methadone implicated but neither heroin nor buprenorphine. Hazard ratios (HRs) were assessed using proportional hazards regression.

FINDINGS

Scotland's CHI-identified methadone-prescription cohort comprised 33,128 clients, 121,254 pys, 1,171 non-DRDs and 760 DRDs (6.3 per 1,000 pys), of which 362 were methadone-specific. Irrespective of gender, methadone-specific DRD-rate, per 1,000 pys, was higher in the 35+ age-group (4.2; 95% CI: 3.6-4.7) than for younger clients (1.9; 95% CI: 1.5-2.2). For methadone-specific DRDs, age-related HRs (e.g., 2.9 at 45+ years; 95% CI: 2.1-3.9) were steeper than for all DRDs (1.9; 95% CI: 1.5-2.4); there was no hazard-reduction for females; no gender by age-group interaction; and, unlike for all DRDs, the highest quintile for quantity of prescribed methadone at cohort-entry (>1960mg) was associated with increased HR (1.8; 95% CI: 1.3-2.5).

CONCLUSION

Higher methadone-specific DRD rates in older clients, irrespective of gender, call for better understanding of methadone's pharmaco-dynamics in older, opioid-dependent clients, many with progressive physical or mental ill-health.

Is treatment for alcohol use disorder associated with reductions in criminal offending? A national data linkage cohort study in England

BACKGROUND

This is the first English national study of change in criminal offending following treatment for alcohol use disorder (AUD).

METHODS

All adults treated for AUD by all publicly funded treatment services during April 2008-March 2009 (n=53,017), with data linked to the Police National Computer (April 2006-November 2011). Pre-treatment offender sub-populations were identified by Latent Profile Analysis. The outcome measure was the count of recordable criminal offences during two-year follow-up after admission. A mixed-effects, Poisson regression modelled outcome, adjusting for demographics and clinical information, the latent classes, and treatment exposure covariates.

RESULTS

Twenty-two percent of the cohort committed one or more offences in the two years pre-treatment (n=11,742; crude rate, 221.5 offenders per 1000). During follow-up, the number of offenders and offences fell by 23.5% and 24.0%, respectively (crude rate, 69.4 offenders per 1000). During follow-up, a lower number of offences was associated with: completing treatment (adjusted incident rate ratio [IRR] 0.82; 95% confidence interval [CI] 0.79-0.85); receiving inpatient detoxification (IRR 0.84; CI 0.80-0.89); or community pharmacological therapy (IRR 0.89; CI 0.84-0.96). Reconviction was reduced in the sub-population characterised by driving offences (n=1,140; 11.7%), but was relatively high amongst acquisitive (n=768; 58.3% reconvicted) and violent offending sub-populations (n=602; 77.6% reconvicted).

CONCLUSIONS

Reduced offending was associated with successful completion of AUD treatment and receiving inpatient and pharmacological therapy, but not enrolment in psychological and residential interventions. Treatment services (particularly those providing psychological therapy and residential care) should be alert to offending, especially violent and acquisitive crime, and enhance crime reduction interventions.

Impact of treatment for opioid dependence on fatal drug-related poisoning: a national cohort study in England

AIMS

To compare the change in illicit opioid users' risk of fatal drug-related poisoning (DRP) associated with opioid agonist pharmacotherapy (OAP) and psychological support, and investigate the modifying effect of patient characteristics, criminal justice system (CJS) referral and treatment completion.

DESIGN

National data linkage cohort study of the English National Drug Treatment Monitoring System and the Office for National Statistics national mortality database. Data were analysed using survival methods.

SETTING

All services in England that provide publicly funded, structured treatment for illicit opioid users.

PARTICIPANTS

Adults treated for opioid dependence during April 2005 to March 2009: 151,983 individuals; 69% male; median age 32.6 with 442,950 person-years of observation.

MEASUREMENTS

The outcome was fatal DRP occurring during periods in or out of treatment, with adjustment for age, gender, substances used, injecting status and CJS referral.

FINDINGS

There were 1499 DRP deaths [3.4 per 1000 person-years, 95% confidence interval (CI) = 3.2-3.6]. DRP risk increased while patients were not enrolled in any treatment [adjusted hazard ratio (aHR) = 1.73, 95% CI = 1.55-1.92]. Risk when enrolled only in a psychological intervention was double that during OAP (aHR = 2.07, 95% CI = 1.75-2.46). The increased risk when out of treatment was greater for men (aHR = 1.88, 95% CI = 1.67-2.12), illicit drug injectors (aHR = 2.27, 95% CI = 1.97-2.62) and those reporting problematic alcohol use (aHR = 2.37, 95% CI = 1.90-2.98).

CONCLUSIONS

Patients who received only psychological support for opioid dependence in England appear to be at greater risk of fatal opioid poisoning than those who received opioid agonist pharmacotherapy.