A day-by-day investigation of changes in criminal convictions before and after entering and leaving opioid maintenance treatment: a national cohort study

Evaluation of heroin-assisted treatment in Norway: protocol for a mixed methods study

BACKGROUND

Opioid agonist treatment (OAT) for patients with opioid use disorder (OUD) has a convincing evidence base, although variable retention rates suggest that it may not be beneficial for all. One of the options to include more patients is the introduction of heroin-assisted treatment (HAT), which involves the prescribing of pharmaceutical heroin in a clinical supervised setting. Clinical trials suggest that HAT positively affects illicit drug use, criminal behavior, quality of life, and health. The results are less clear for longer-term outcomes such as mortality, level of function and social integration. This protocol describes a longitudinal evaluation of the introduction of HAT into the OAT services in Norway over a 5-year period. The main aim of the project is to study the individual, organizational and societal effects of implementing HAT in the specialized healthcare services for OUD.

METHODS

The project adopts a multidisciplinary approach, where the primary cohort for analysis will consist of approximately 250 patients in Norway, observed during the period of 2022-2026. Cohorts for comparative analysis will include all HAT-patients in Denmark from 2010 to 2022 (N = 500) and all Norwegian patients in conventional OAT (N = 8300). Data comes from individual in-depth and semi-structured interviews, self-report questionnaires, clinical records, and national registries, collected at several time points throughout patients' courses of treatment. Qualitative analyses will use a flexible inductive thematic approach. Quantitative analyses will employ a wide array of methods including bi-variate parametric and non-parametric tests, and various forms of multivariate modeling.

DISCUSSION

The project's primary strength lies in its comprehensive and longitudinal approach. It has the potential to reveal new insights on whether pharmaceutical heroin should be an integral part of integrated conventional OAT services to individually tailor treatments for patients with OUD. This could affect considerations about drug treatment even beyond HAT-specific topics, where an expanded understanding of why some do not succeed with conventional OAT will strengthen the knowledge base for drug treatment in general. Results will be disseminated to the scientific community, clinicians, and policy makers.

TRIAL REGISTRATION

The study was approved by the Norwegian Regional Committee for Medical and Health Research Ethics (REK), ref.nr.:195733.

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.

Association between the discontinuation of substance use inpatient treatment and the risk of committing a crime leading to imprisonment: A Finnish registry-based 5-year follow-up

BACKGROUND

Discontinuation of substance use inpatient treatment is common, generally due to dropout and rule breaking. In turn, this is associated with worse long-term substance use outcomes.

AIM

To investigate whether people who discontinued voluntary inpatient substance use treatment have a higher risk of imprisonment for a crime within 5 years of discontinuance than those who completed treatment.

METHODS

This registry-based follow-up study focused on all inpatient treatment episodes between 2002 and 2009 (N = 2893) in a Finnish hospital for treating addictions. Data from national registers on criminality, hospitalisations and education were linked. Cox regression analysis was used.

RESULTS

Discontinued treatment episodes were 1.4 times more likely to be followed by criminality leading to imprisonment during the 5-year follow-up period compared with completed treatment periods, after adjusting for age, gender, education, substance use diagnoses, earlier mental health disorders and prior imprisonments.

CONCLUSIONS

Our findings strengthen the argument for ensuring completion of substance use treatment episodes; better completion rates could decrease the harm caused by serious criminality. Indeed, we recommend that crime reduction should be included to the long-term goals of substance use treatment.

Retention in the Austrian opioid agonist treatment system: a national prospective cohort study

BACKGROUND

Retention in care is a prerequisite for successful recovery, especially for a chronic condition like opioid dependence. Though retention varies greatly depending on the different substitution medication and treatment model, treatment retention is used as an indicator of treatment quality and effectiveness of care on a system and individual level. To monitor the overall quality of the Austrian opioid agonist treatment (OAT) system and to monitor patient satisfaction within the system, a new online-based registry called "eSuchmittel" was introduced in Austria at the beginning of 2011. The objective of this study is to analyze retention rates within the Austrian treatment system and to identify patient characteristics associated with retention, using data collected by the substitution registry.

METHODS

The complete Austrian sample of 4778 registered patients starting treatment between 1.1.2011 to 31.12.2012 were included in the prospective cohort study using data from the Austrian substitution registry. For the statistical analysis, multivariate Cox Regression and Kaplan-Meier survival analysis were used to evaluate retention in treatment.

RESULTS

The retention rate of the total cohort after two years was around 61%. Retention rates were significantly lower for men (exp(B) = .806, 95% CI 0.714-0.908) and significantly higher for patients aged 30 and older (exp(B) = 1.155, 95% CI 1.044-1.279), among patients located in Vienna (exp(B) = 1.439, 95% CI 1.273-1.626) and among patients prescribed oral slow-release morphine (SROM) (exp(B) = 2.141, 95% CI 1.885-2.430).

CONCLUSIONS

Average retention in the Austrian system is high in comparison to international retention rates. Nationally, SROM demonstrates higher treatment retention when compared to other available substitution medications. Sociodemographic and regional indicators also contribute to higher retention in care. A systematic monitoring of retention rates within a national registry is an important tool helping to evaluate the quality of care. In this study, the Austrian OAT system proves very high retention in care, an important success criterion.

The effect of entry and retention in opioid agonist treatment on contact with the criminal justice system among opioid-dependent people: a retrospective cohort study

BACKGROUND

Evidence on the effectiveness of opioid agonist treatment (OAT) in reducing crime is mixed. We aimed to assess the effect of OAT on crime in terms of delaying time to first charge and reducing overall charge rates, as well as the relationship between OAT retention and overall charge rates.

METHODS

We did a retrospective cohort study of opioid-dependent people who entered OAT for the first time between Jan 1, 2004, and Dec 30, 2010, in New South Wales (NSW), Australia. We used three linked NSW and national administrative datasets. Data on OAT were obtained from the Pharmaceutical Drugs of Addiction System, data on charges were obtained from the Reoffending Database, and data on mortality were obtained from the National Death Index. The cohort was followed up until Dec 31, 2011. Time-dependent OAT exposure was modelled using Cox proportional hazards models (time to first charge) and Andersen-Gill intensity models (total charge-days). Retention in OAT was modelled using two features of treatment engagement, number of OAT episodes and proportion of follow-up time in OAT (presented in quartile groupings: lowest, low-mid, low-high, highest) using zero-inflated negative binomial regression (total charges). All models were adjusted for sociodemographic, criminographic, and treatment-related variables.

FINDINGS

10 744 new OAT entrants were included in the study. 5751 (53·5%) people were charged with an offence. In adjusted analyses, OAT was associated with an initial benefit in delaying the time to first charge (hazard ratio 0·43, 95% CI 0·33-0·55) and reducing total charge-days (0·39, 95% CI 0·30-0·52); however, these protective effects reduced over time. Total charge rates were higher as the number of OAT episodes increased (incident rate ratio [IRR] 1·13, 95% CI 1·11-1·15), and when relatively lower proportions of time were spent in OAT (IRR among the lowest three quartiles ranged from 1·11 [95% CI 1·02-1·21] to 1·22 [95% CI 1·12-1·33]).

INTERPRETATION

OAT was associated with a reduction in overall charge rates and was more protective as treatment engagement increased. Maximising treatment retention is crucial to achieving long-term health and social benefits of OAT.

FUNDING

Australian National Health and Medical Research Council, Australian Institute of Criminology, National Institute on Drug Abuse, Australian Government Department of Health, UNSW Sydney.

How handling missing data may impact conclusions: A comparison of six different imputation methods for categorical questionnaire data

Objectives:

Missing data is a recurrent issue in many fields of medical research, particularly in questionnaires. The aim of this article is to describe and compare six conceptually different multiple imputation methods, alongside the commonly used complete case analysis, and to explore whether the choice of methodology for handling missing data might impact clinical conclusions drawn from a regression model when data are categorical.

Methods:

In addition to the commonly used complete case analysis, we tested the following six imputation methods: multiple imputation using expectation–maximization with bootstrapping, multiple imputation using multiple correspondence analysis, multiple imputation using latent class analysis, multiple hot deck imputation and multivariate imputation by chained equations with two different model specifications: logistic regression and random forests. The methods are tested on real data from a questionnaire-based study in the Norwegian opioid maintenance treatment programme.

Results:

All methods performed relatively well when the sample size was large (n = 1000). For a smaller sample size (n = 200), the regression estimates depend heavily on the level of missing. When the amount of missing was ⩾20%, in particular, complete case analysis, hot deck and random forests had biased estimates with too low coverage. Multiple imputation using multiple correspondence analysis had the best performance all over.

Conclusion:

The choice of missing handling methodology has a significant impact on the clinical interpretation of the accompanying statistical analyses. With missing data, the choice of whether to impute or not, and choice of imputation method, can influence clinical conclusion drawn from a regression model and should therefore be given sufficient consideration.

Effectiveness of Injectable Extended-Release Naltrexone vs Daily Buprenorphine-Naloxone for Opioid Dependence: A Randomized Clinical Noninferiority Trial

Importance

To date, extended-release naltrexone hydrochloride has not previously been compared directly with opioid medication treatment (OMT), currently the most commonly prescribed treatment for opioid dependence.

Objective

To determine whether treatment with extended-release naltrexone will be as effective as daily buprenorphine hydrochloride with naloxone hydrochloride in maintaining abstinence from heroin and other illicit substances in newly detoxified individuals.

Design, Setting and Participants

A 12-week, multicenter, outpatient, open-label randomized clinical trial was conducted at 5 urban addiction clinics in Norway between November 1, 2012, and December 23, 2015; the last follow-up was performed on October 23, 2015. A total of 232 adult opioid-dependent (per DSM-IV criteria) individuals were recruited from outpatient addiction clinics and detoxification units and assessed for eligibility. Intention-to-treat analyses of efficacy end points were performed with all randomized participants.

Interventions

Randomization to either daily oral flexible dose buprenorphine-naloxone, 4 to 24 mg/d, or extended-release naltrexone hydrochloride, 380 mg, administered intramuscularly every fourth week for 12 weeks.

Main Outcomes and Measures

Primary end points (protocol) were the randomized clinical trial completion rate, the proportion of opioid-negative urine drug tests, and number of days of use of heroin and other illicit opioids. Secondary end points included number of days of use of other illicit substances. Safety was assessed by adverse event reporting.

Results

Of 159 participants, mean (SD) age was 36 (8.6) years and 44 (27.7%) were women. Eighty individuals were randomized to extended-release naltrexone and 79 to buprenorphine-naloxone; 105 (66.0%) completed the trial. Retention in the extended-release naltrexone group was noninferior to the buprenorphine-naloxone group (difference, -0.1; with 95% CI, -0.2 to 0.1; P = .04), with mean (SD) time of 69.3 (25.9) and 63.7 (29.9) days, correspondingly (P = .33, log-rank test). Treatment with extended-release naltrexone showed noninferiority to buprenorphine-naloxone on group proportion of total number of opioid-negative urine drug tests (mean [SD], 0.9 [0.3] and 0.8 [0.4], respectively, difference, 0.1 with 95% CI, -0.04 to 0.2; P < .001) and use of heroin (mean difference, -3.2 with 95% CI, -4.9 to -1.5; P < .001) and other illicit opioids (mean difference, -2.7 with 95% CI, -4.6 to -0.9; P < .001). Superiority analysis showed significantly lower use of heroin and other illicit opioids in the extended-release naltrexone group. No significant differences were found between the treatment groups regarding most other illicit substance use.

Conclusions and Relevance

Extended-release naltrexone was as effective as buprenorphine-naloxone in maintaining short-term abstinence from heroin and other illicit substances and should be considered as a treatment option for opioid-dependent individuals.

Trial Registration

clinicaltrials.gov Identifier: NCT01717963.

The costs of crime during and after publicly funded treatment for opioid use disorders: a population-level study for the state of California

BACKGROUND AND AIMS

Treatment for opioid use disorders (OUD) reduces the risk of mortality and infectious disease transmission; however, opportunities to quantify the potential economic benefits of associated decreases in drug-related crime are scarce. This paper aimed to estimate the costs of crime during and after periods of engagement in publicly funded treatment for OUD to compare total costs of crime during a hypothetical 6-month period following initiation of opioid agonist treatment (OAT) versus detoxification.

DESIGN

Retrospective, administrative data-based cohort study with comprehensive information on drug treatment and criminal justice systems interactions.

SETTING

Publicly funded drug treatment facilities in California, USA (2006-10).

PARTICIPANTS

A total of 31 659 individuals admitted for the first time to treatment for OUD, and who were linked with criminal justice and mortality data, were followed during a median 2.3 years. Median age at first treatment admission was 32, 35.8% were women and 37.1% primarily used prescription opioids.

MEASUREMENTS

Daily costs of crime (US$2014) were calculated from a societal perspective and were composed of the costs of policing, court, corrections and criminal victimization. We estimated the average marginal effect of treatment engagement in OAT or detoxification adjusting for potential fixed and time-varying confounders, including drug use and criminal justice system involvement prior to treatment initiation.

FINDINGS

Daily costs of crime during treatment compared with after treatment were $126 lower for OAT [95% confidence interval (CI) = $116, $136] and $144 lower for detoxification (95% CI = $135, $154). Summing the costs of crime during and after treatment over a hypothetical 6-month period using the observed median durations of OAT (161 days) and detoxification (19 days), we estimated that enrolling an individual in OAT as opposed to detoxification would save $17 550 ($16 840, $18 383).

CONCLUSIONS

In publicly funded drug treatment facilities in California, USA, engagement in treatment for opioid use disorders is associated with lower costs of crime in the 6 months following initiation of treatment, and the economic benefits were far greater for individuals receiving time-unlimited treatment.

Design of a randomized controlled trial of extended-release naltrexone versus daily buprenorphine-naloxone for opioid dependence in Norway (NTX-SBX)

BACKGROUND

Current guidelines for opioid dependence recommend daily maintenance of physical dependence with methadone or buprenorphine, and discourage abstinence due to the high risk of relapse and overdose. Extended-release formulations of the opioid antagonist naltrexone (XR-NTX) block heroin and other opioid agonists competitively for around 4 weeks per administration. XR-NTX thus enables opioid users to experience abstinence from opioid agonists with greatly reduced risk of overdose compared to medication-free abstinence. While XR-NTX has shown promise compared to placebo and daily naltrexone tablets, there is limited information on long-term safety and its performance compared to daily maintenance treatment.

METHODS/DESIGN

In this five-hospital RCT with long-term follow-up, we aim to recruit n = 180 patients in treatment for opioid dependence and allocate them in an open, randomized manner (1:1) to receive either 4-week XR-NTX or daily buprenorphine-naloxone (BP-NLX) for the duration of 12 weeks. Allocation is open-label due to the risk of overdose during attempts to self-unmask allocation using heroin. Urine drug tests are scheduled every week with follow-up visits & assessment every 4 weeks. Primary outcomes are abstinence from illicit opioids in urine drug tests and self-report, as well as retention in treatment. Secondary outcomes include other substance use, injecting behavior, drug craving, mental health, quality of life, treatment satisfaction, abstinence motivation, opioid agonist effect rating, insomnia, and pain. Observation is continued for another 36 weeks in order to assess longer-term safety, adherence and effectiveness. The study is an investigator-initiated trial, funded by public grants and approved by an Independent Ethical Committee (the Regional Ethical Committee for Research South-East B # 2011/1320) and the Norwegian Medicines Agency.

DISCUSSION

Despite minor implementation problems, the protocol appears sufficiently robust to generate results of high interest to patients, clinicians and policy makers.

TRIAL REGISTRATION

Clinicaltrials.gov # NCT01717963 , first registered: Oct 28, 2012. Protocol version # 3C, June 12th 2012.

Dynamics in the costs of criminality among opioid dependent individuals

BACKGROUND

Research into the avoided crime-related costs associated with methadone maintenance treatment (MMT) is sparse. Our objective was to characterize the dynamics in crime-related costs associated with MMT effectiveness among opioid dependent individuals in Vancouver, Canada.

METHODS

We considered individuals enrolled in a prospective study between December, 2011 and May, 2013. Monthly crime-related costs (2013 CAD) were derived from self-reported criminal activity. On the basis of MMT receipt and illicit opioid use, individuals were classified in mutually exclusive health states: (i) MMT high effectiveness; (ii) MMT low effectiveness; (iii) opioid abstinence; or (iv) relapse. We classified individuals as daily, non-daily or non-stimulant users and controlled for demographic and socio-economic characteristics. A two-part multiple regression model was constructed; the first part modeled non-zero cost probability, the second estimated the level of costs. Avoided costs were estimated for each health state and stratified by stimulant use intensity.

RESULTS

Our study included 982 individuals (median age 47, 38% female) for 2232 observations. Individuals on MMT with high effectiveness incurred lower monthly costs of criminality (avoided costs of $6298; 95% C.I. ($1578, $11,017)), as did opioid abstinent individuals ($6563 ($1564, $11,561)). Avoided costs for daily stimulant users were greater than for non-daily users, both for individuals on MMT with high effectiveness ($12,975 vs. $4125) and opioid abstinent ($12,640 vs. $4814).

CONCLUSION

Using longitudinal data on individuals with a history of MMT, we found substantially lower costs of criminality associated with high effect to MMT. Avoided costs were highest among daily stimulant users that were on MMT with high effectiveness or those opioid abstinent.

Patients who terminate OMT--how do they fare?

BACKGROUND

OMT tends to involve treatment over an extended period of time. Some OMT patients terminate the treatment. There is a need for more knowledge about how these persons do following treatment.

MATERIAL AND METHOD

We undertook a retrospective review of patient records at Sørlandet Hospital in Kristiansand for patients who had undergone OMT in the period 1998-2009. Data from 103 discharged patients were included in the study, registered on two occasions--31 December 2009 and 30 June 2011.

RESULTS

Of the 469 patients who started their OMT during the period of study, altogether 103 patients (22%) terminated the treatment. One-half of the 103 patients who terminated their treatment did so because they no longer wanted OMT or failed to report to the hospital. The others terminated the treatment because they wanted medication from their GP other than OMT (n = 11), because they considered themselves to be no longer addicted and in need of treatment (n = 19) or because they maintained a considerable substance use (n = 21). Seven patients wanted a planned tapering-off of OMT drugs. The status for these 103 discharged patients as of 31 December 2009 (median 1,034 days after discharge) was: uncontrolled substance use: 30%; dead: 17%; other medication from GP: 14%; psychiatric treatment: 12%; imprisoned: 8%; OMT in another county: 2%; drug-free without maintenance treatment: 11%; unknown: 6%. Eighteen months later, altogether 36 of them had changed their status. The group with uncontrolled substance use (n = 31) had undergone the greatest change--altogether 14 were back in OMT, ten continued their substance use and four had died.

INTERPRETATION

The OMT patients who terminated the treatment had a high rate of mortality. Approximately 10 % of those discharged lived stable drug-free lives without OMT medication during the period of observation.

Accounting for individual differences and timing of events: estimating the effect of treatment on criminal convictions in heroin users

Background

The reduction of crime is an important outcome of opioid maintenance treatment (OMT). Criminal intensity and treatment regimes vary among OMT patients, but this is rarely adjusted for in statistical analyses, which tend to focus on cohort incidence rates and rate ratios. The purpose of this work was to estimate the relationship between treatment and criminal convictions among OMT patients, adjusting for individual covariate information and timing of events, fitting time-to-event regression models of increasing complexity.

Methods

National criminal records were cross linked with treatment data on 3221 patients starting OMT in Norway 1997–2003. In addition to calculating cohort incidence rates, criminal convictions was modelled as a recurrent event dependent variable, and treatment a time-dependent covariate, in Cox proportional hazards, Aalen’s additive hazards, and semi-parametric additive hazards regression models. Both fixed and dynamic covariates were included.

Results

During OMT, the number of days with criminal convictions for the cohort as a whole was 61% lower than when not in treatment. OMT was associated with reduced number of days with criminal convictions in all time-to-event regression models, but the hazard ratio (95% CI) was strongly attenuated when adjusting for covariates; from 0.40 (0.35, 0.45) in a univariate model to 0.79 (0.72, 0.87) in a fully adjusted model. The hazard was lower for females and decreasing with older age, while increasing with high numbers of criminal convictions prior to application to OMT (all p < 0.001). The strongest predictors were level of criminal activity prior to entering into OMT, and having a recent criminal conviction (both p < 0.001). The effect of several predictors was significantly time-varying with their effects diminishing over time.

Conclusions

Analyzing complex observational data regarding to fixed factors only overlooks important temporal information, and naïve cohort level incidence rates might result in biased estimates of the effect of interventions. Applying time-to-event regression models, properly adjusting for individual covariate information and timing of various events, allows for more precise and reliable effect estimates, as well as painting a more nuanced picture that can aid health care professionals and policy makers.