Short-term Outcomes for the Treatment of Heroin Dependence: Findings From the Australian Treatment Outcome Study (ATOS)

Patterns and Predictors of Heroin Use, Remission, and Psychiatric Health Among People with Heroin Dependence: Key Findings from the 18-20-Year Follow-Up of the Australian Treatment Outcome Study (ATOS)

This study aimed to investigate the long-term patterns and predictors of heroin use, dependence, and psychiatric health over 18-20 years among a cohort of Australians with heroin dependence, using a prospective longitudinal cohort study conducted in Sydney, Australia. The original cohort consisted of 615 participants, who were followed up at 3 months and 1, 2, 3, 11, and 18-20 years post-baseline; 401 (65.2%) were re-interviewed at 18-20 years. The Australian Treatment Outcome Study structured interview with established psychometric properties was administered to participants at each follow-up, addressing demographics, treatment and drug use history, overdose, crime, and physical and mental health. Overall, 96.7% completed at least one follow-up interview. At 18-20 years, 109 participants (17.7%) were deceased. Past-month heroin use decreased significantly over the study period (from 98.7 to 24.4%), with one in four using heroin at 18-20 years. Just under half were receiving treatment. Reductions in heroin use were accompanied by reductions in heroin dependence, other substance use, needle sharing, injection-related health, overdose, crime, and improvements in general physical and mental health. Major depression and borderline personality disorder (BPD) were consistently associated with poorer outcome. At 18-20 years, there is strong evidence that clinically significant levels of improvement can be maintained over the long term. The mortality rate over 18-20 years was devastating, with over one in six participants deceased. More sustained and targeted efforts are needed in relation to major depression and BPD to ensure evidence-based treatments are delivered to people with heroin dependence.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-022-01006-6.

Predictors of Relapse to Alcohol and Substance Use: Are There Any Differences between 3 and 12 Months after Inpatient Treatment?

Understanding the factors that lead to relapse is important for developing effective treatment strategies. The aim of this study is to examine sociodemographic and clinical factors that predict relapse 3 and 12 months after inpatient treatment in patients with alcohol and substance use disorders. 247 patients were included in the study. A sociodemographic data form and the Addiction Profile Index-Clinical Form (API-C) were filled out during the first days of hospitalization and relapse information was obtained through outpatient interviews. Logistic regression analysis was used to assess predictive factors. Rates of relapse for the 3^rd and 12^th months were 40.5% and 74.6%, respectively. Motivation to quit substance use, risk of depression, being on probation, and being employed predicted relapse within the 3-month period. At the 12^th month, substance use intensity and motivation to quit were the factors associated with relapse. To conclude, motivation to quit is critical to maintaining both early and sustained remission. Moreover, divergent factors may be relevant at different stages of treatment. Defining relapse predictors early in the process and being vigilant to the change in the needs of patients as the treatment continues may help to develop a more effective and focused treatment plan.

Rumination and problematic substance use among individuals with a long-term history of illicit drug use

BACKGROUND

Rumination is a cognitive process that is implicated in the development and maintenance of various forms of psychopathology, including problematic substance use. Most studies on the role of rumination in substance use have been conducted among community samples or individuals with alcohol use disorders and have predominately focused on overall rumination rather than differentiating between its subtypes, ruminative brooding and ruminative reflection. The current study therefore aimed to investigate i) whether rumination subtypes are associated with problematic substance use among people with a long-term history of illicit drug use independently of related psychological disorders (depression and post-traumatic stress disorder [PTSD]), and ii) whether gender moderates these relationships.

METHODS

This cross-sectional study used data from the Australian Treatment Outcome Study (ATOS); a naturalistic prospective cohort study of people with heroin dependence. At the 11-year follow-up of ATOS, a total of 380 participants completed measures of rumination, depression, PTSD, and indices of problematic substance use.

RESULTS

Hierarchical logistic regression analyses indicated that higher brooding scores were associated with current heroin dependence (OR = 1.11, CI: 1.01-1.22), polydrug use (OR = 1.16, CI: 1.06-1.28) and experience of injection related health problems (OR = 1.08, CI: 1.00-1.17), independently of depression, PTSD, and other covariates. Reflection was not related to any of the substance use measures. These results were not moderated by gender.

CONCLUSIONS

Findings indicate that ruminative brooding is related to a poorer substance use profile among people with long-term illicit drug use and highlight the potential benefits of targeting brooding during substance use treatment.

Frequency and severity of non-fatal opioid overdoses among clients attending the Sydney Medically Supervised Injecting Centre

BACKGROUND

Pharmaceutical opioid overdose rates have increased in recent years. The current study aimed to compare rates per 1000 injections of non-fatal overdose after heroin or oxycodone injection, and their comparative clinical severity.

METHODS

Analysis of prospectively collected data from the Sydney Medically Supervised Injecting Centre (MSIC). Severity of overdose was measured using the Glasgow Coma Scale, oxygen saturation levels, and the administration of naloxone.

RESULTS

Heroin overdoses occurred at three times the rate of oxycodone overdoses (12.7 v 4.1 per 1000 injections). Heroin overdoses appeared to be more severe than oxycodone overdoses, with higher levels of compromised consciousness (31 v 18%) and severe respiratory depression (67 v 48%), but there were no differences in naloxone doses (20 v 17%). Concurrent use of other depressants at the time of overdose was also associated with compromised consciousness, and the need for naloxone.

CONCLUSIONS

Heroin overdoses occurred at a greater rate than oxycodone overdoses, and had more severe clinical indicators.

Gender and Age Effects on the Trajectory of Depression in Opioid Users during Methadone Maintenance Treatment

INTRODUCTION

Both heroin use and depression are significant health problems. Methadone maintenance treatment (MMT) can be of great benefit to heroin users. However, changes in the level of depression in heroin users during MMT are not clear. Gender and age are also important factors in the development of depression, and whether gender and age moderate changes in depression in heroin users during MMT warrants further study. This study aimed to explore: (1) the trajectory of depression in opioid users during MMT and (2) the moderating effects of gender and age on the trajectory of depression in opioid users receiving MMT.

METHOD

A total of 294 intravenous heroin users were recruited into this 9-month observational study. The level of depression was measured at the intake interview and at follow-up interviews every 3 months. A latent growth model was used to analyze the trajectory of the level of depression among the participants.

RESULTS

Depression improved rapidly during the first 3 months of MMT and slowly after the first 3 months in both the female and male heroin users. There was no gender difference in the level of depression at each follow-up point. The level of depression in the female heroin users decreased faster than that in the male heroin users. In addition, the level of depression in the younger heroin users decreased faster than that in the older subjects.

CONCLUSION

Depression in female and younger heroin users improved more rapidly than in male and older subjects, respectively.

Years of potential life lost amongst heroin users in the Australian Treatment Outcome Study cohort, 2001-2015

BACKGROUND

Heroin use carries the highest burden of disease of any drug of dependence. The study aimed to determine mortality rates of the Australian Treatment Outcome Study cohort over the period 2001-2015, and the years of potential life lost (YPLL).

METHODS

The cohort consisted of 615 heroin users. Crude mortality rates per 1000 person years (PY) and Standardised Mortality Ratios (SMR) were calculated. YPLL were calculated using two criteria: years lost prior to age 65, and years lost prior to average life expectancy.

RESULTS

The cohort was followed for 7,790.9 PY. At 2015, 72 (11.7%) of the cohort were deceased, with a crude mortality rate of 9.2 per 1000 PYs. Neither age nor gender associated with mortality. The SMR was 10.2 (males 7.3, females 17.2), matched for age, gender and year of death. The most common mortality cause was opioid overdose (52.8%). Using the<65 years criterion, there were 1988.3 YPLL, with a mean of 27.6 (males 27.6, females 27.7). Using the average life expectancy criterion, there were 3135.1 YPLL, with a mean of 43.5 (males 41.9, females 46.3). Accidental overdose (<65 yr 63.0%, average life expectancy 63.7%) and suicide (<65 yr 12.8%, average life expectancy 13.3%) accounted for three quarters of YPLL where cause of death was known.

CONCLUSIONS

YPLL associated with heroin use was a quarter of a century, or close to half a century, depending on the criteria used. Given the prominent role of overdose and suicide, the majority of these fatalities, and the associated YPLL, appear preventable.

Patterns and correlates of alcohol use amongst heroin users: 11-year follow-up of the Australian Treatment Outcome Study cohort

INTRODUCTION

The study aimed to determine long-term alcohol use patterns and correlates amongst heroin users.

METHODS

Longitudinal cohort. 11-year post-baseline follow-up of the Australian Treatment Outcome Study cohort.

RESULTS

At 11-year follow-up, 431 (70%) participants were interviewed. Alcohol was used in the preceding month by 56%, with 27% reporting daily use and 11% heavy daily drinking. Alcohol use patterns showed remarkable consistency across waves, with the proportion who drank in the preceding month ranging between 49 and 56%, with no significant trend across time. Daily drinking ranged between 20 and 27%, and heavy daily drinking between 7 and 12%. Both declined slightly from baseline to 3-year follow-up, but by 11 years were at levels similar to baseline. Compared to female referents, males were more likely to drink (OR 1.6, CI 1.3-2.1, p < .05), to drink daily (OR 1.8, CI 1.4-2.4, p < .05) and to drink heavily (OR 1.7, 1.1-2.5, p < .05). Compared to those not in enrolled in a drug treatment programme, those enrolled were significantly less likely to drink (OR 0.7, CI 0.5-0.8, p < .05) and to drink daily (OR 0.6, 0.5-0.8, p < .05). Compared to those who did not drink heavily, heavy drinking was associated with a higher likelihood of recent overdose (OR 1.6, CI 1.0-2.4, p < .05), of criminality (OR 1.9, 1.3-2.7, p < .001), and with lower SF12 physical (mean difference -3.0, CI -4.7 to -1.4, p < .001) and mental (-2.4, CI -4.3 to -0.5, p < .001) health scores.

CONCLUSIONS

There were consistently high levels of both abstinence and regular drinking, with drinking patterns staying relatively stable across the decade. From the clinical perspective, the high rates of heavy drinking are of particular relevance, given the observed associations with a poorer clinical profile.

Patterns and correlates of attempted suicide amongst heroin users: 11-year follow-up of the Australian treatment outcome study cohort

Lifetime and recent rates of attempted suicide and suicidal ideation amongst the Australian Treatment Outcome Study cohort of heroin users at 11-year follow-up were examined. The mean elapsed time since heroin initiation was 20.4 years. At 11-year follow-up, 42.2% of the cohort reported ever having made a suicide attempt, 11.1% having made a first attempt subsequent to baseline. In the year preceding 11-year follow-up, 1.6% had made an attempt, suicidal ideation was reported by 10.4%, and 4.2% had a current suicide plan. After controlling for other variables, past 12 month attempts, current ideation or plans were independently associated with a current diagnosis of Major Depression (odds ratios (OR) 1.67) and more extensive polydrug use (OR 1.39), while each standard deviation higher on the SF12 physical health scale (reflecting better health) was associated with reduced odds (OR 0.66). Suicide and suicidal ideation remained a significant clinical issue for heroin users, some 20 years after their heroin use commenced.

Long-term mortality, remission, criminality and psychiatric comorbidity of heroin dependence: 11-year findings from the Australian Treatment Outcome Study

AIMS

To determine the long-term mortality, remission, criminality and psychiatric comorbidity during 11 years among heroin-dependent Australians.

DESIGN

Longitudinal cohort study.

SETTING

Sydney, Australia.

PARTICIPANTS

A total of 615 participants were recruited and completed baseline interviews between 2001 and 2002. Participants completed follow-up interviews at 3, 12, 24 and 36 months post-baseline, and again at 11 years post-baseline; 431 (70.1%) of the original 615 participants completed the 11-year follow-up.

MEASUREMENTS

Participants were administered the Australian Treatment Outcome Study (ATOS) structured interview, addressing demographics, treatment history, drug use, heroin overdose, criminality, health and mental health at all interviews. Overall, 96.1% of the cohort completed at least one follow-up interview.

FINDINGS

At 11 years, 63 participants (10.2%) were deceased. The proportion of participants who reported using heroin in the preceding month decreased significantly from baseline (98.7%) to 36-month follow-up (34.0%; odds ratio = 0.01; 95% confidence interval = 0.00, 0.01) with further reductions evident between 36 months and 11 years (24.8%). However, one in four continued to use heroin at 11 years, and close to one-half (46.6%) were in current treatment. The reduction in current heroin use was accompanied by reductions in risk-taking, crime and injection-related health problems, and improvements in general physical and mental health. The relationship with treatment exposure was varied. Major depression was associated consistently with poorer outcome.

CONCLUSIONS

In an 11-year follow-up of patients undergoing treatment for heroin dependence, 10.2% had died and almost half were still in treatment; the proportion still using heroin fell to a quarter, with major depression being a significant predictor of continued use.

Patterns and correlates of non-fatal heroin overdose at 11-year follow-up: findings from the Australian Treatment Outcome Study

BACKGROUND

Overdose is a major cause of morbidity and mortality amongst opioid users. This paper reported recent non-fatal overdose amongst the Australian Treatment Outcome Study (ATOS) cohort at 11-year follow-up, and characteristics that predict recent overdose.

METHODS

Longitudinal cohort, with 431 (70.1%) of the original 615 participants interviewed. Participants were administered the ATOS structured interview, addressing demographics, treatment history, drug use, heroin overdose, criminality, health and psychopathology.

FINDINGS

Mean time since heroin initiation was 20.4 years. By 11-year follow-up, the proportion who had overdosed was 67.5%, and 24.4% had experienced five or more overdoses. In the 12 months preceding 11-year follow-up, 4.9% had overdosed (11.8% of those who had used heroin in that period). Of the 21 participants who had recently overdosed, 20 (95.2%) had overdosed previously, and 19 (90.5%) were not enrolled in a treatment programme at the time. Those who had recently overdosed reported higher levels of use of opiates other than heroin (57.1% vs 24.9%), benzodiazepines (61.9% vs 30.5%,), methamphetamine (38.1% vs 16.8%) and cocaine (19.0% vs 3.7%). They also had exhibited higher levels of heroin use and other drug use at baseline, 12 and 24 month follow-ups.

CONCLUSIONS

While the prevalence had declined, overdoses still occurred. A history of overdose and polydrug use patterns continued to provide strong markers for those at continued risk.

Oral substitution treatment of injecting opioid users for prevention of HIV infection

BACKGROUND

Injecting drug users are vulnerable to infection with Human Immunodeficiency Virus (HIV) and other blood borne viruses as a result of collective use of injecting equipment as well as sexual behaviour

OBJECTIVES

To assess the effect of oral substitution treatment for opioid dependent injecting drug users on risk behaviours and rates of HIV infections

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and PsycINFO to May 2011. We also searched reference lists of articles, reviews and conference abstracts

SELECTION CRITERIA

Studies were required to consider the incidence of risk behaviours, or the incidence of HIV infection related to substitution treatment of opioid dependence. All types of original studies were considered. Two authors independently assessed each study for inclusion

DATA COLLECTION AND ANALYSIS

Two authors independently extracted key information from each of the included studies. Any differences were resolved by discussion or by referral to a third author.

MAIN RESULTS

Thirty-eight studies, involving some 12,400 participants, were included. The majority were descriptive studies, or randomisation processes did not relate to the data extracted, and most studies were judged to be at high risk of bias. Studies consistently show that oral substitution treatment for opioid-dependent injecting drug users with methadone or buprenorphine is associated with statistically significant reductions in illicit opioid use, injecting use and sharing of injecting equipment. It is also associated with reductions in the proportion of injecting drug users reporting multiple sex partners or exchanges of sex for drugs or money, but has little effect on condom use. It appears that the reductions in risk behaviours related to drug use do translate into reductions in cases of HIV infection. However, because of the high risk of bias and variability in several aspects of the studies, combined totals were not calculated.

AUTHORS' CONCLUSIONS

Oral substitution treatment for injecting opioid users reduces drug-related behaviours with a high risk of HIV transmission, but has less effect on sex-related risk behaviours. The lack of data from randomised controlled studies limits the strength of the evidence presented in this review.

Rates and correlates of mortality amongst heroin users: findings from the Australian Treatment Outcome Study (ATOS), 2001-2009

The study aimed to determine mortality rates, standardised mortality ratios (SMRs), and correlates of mortality amongst the Australian Treatment Outcome Study (ATOS) cohort of 615 heroin users over the period 2001-2009. The cohort was followed for a total of 4820.1 person years. A total of 31 deaths (5% of the cohort) occurred across follow-up. The mean age at death was 34.5 years, and 58% were male. The most common cause of death was overdose (68%). The crude mortality rate was 6.43 per 1000 person years, with no gender difference, and the SMR was 4.56 (males=2.95, females=18.57). The only significant bivariate (hazard ratio=3.69) and multivariate (adjusted hazard ratio=3.03) correlate of mortality was a history of opioid overdose prior to baseline. Mortality rates were lower than those seen outside Australasia. Screening for overdose by those treating heroin users would be appropriate, and may contribute to reductions in overall mortality.

Benzodiazepine use among heroin users: baseline use, current use and clinical outcome

INTRODUCTION AND AIMS

Benzodiazepine use is associated with elevated levels of harm. The current study aimed to ascertain the long-term nature of the relationship between benzodiazepine use and clinical profile among heroin users.

DESIGN AND METHODS

Longitudinal cohort, with follow-up at 3, 12, 24 and 36 months. Participants were 615 heroin users recruited for the Australian Treatment Outcome Study.

RESULTS

At baseline, current benzodiazepine users were more likely to be committing crime, had poorer psychological health and poorer physical health. Baseline benzodiazepine use was not associated with the likelihood across follow-up of heroin use (P = 0.44), committing crime (P = 0.17), poorer psychological health (P = 0.31) or poorer physical health (P = 0.48). Current benzodiazepine use was, however, associated with a greater likelihood of concurrent heroin use (OR 2.77), crime (OR 2.04), poorer psychological health (beta = -4.47) and poorer physical health (beta = -2.33).

DISCUSSION AND CONCLUSIONS

Clinicians should be aware that reductions in benzodiazepine use are associated with reductions in harm, and that baseline benzodiazepine status does not equate to poor long-term outcome.

Patterns of major depression and drug-related problems amongst heroin users across 36 months

The study aimed to determine patterns of major depression (MD) across 36 months, and the relationship to outcomes for the treatment of heroin dependence. As part of a longitudinal cohort study, 429 heroin users were interviewed at 36 month follow-up. MD declined from 23.8% at baseline to 8.2% at 36 months. Females were more likely to have MD at both baseline (31.1 vs. 19.8) and 36 months (11.9 vs. 6.1%). Those with MD at baseline were significantly more likely to be diagnosed with MD at a follow-up interview (40.2 vs. 15.9%) and at 36 months (14.7 vs. 6.1%). Antidepressant use did not decrease across 36 months amongst either gender. Baseline MD was not related to treatment exposure across 36 months. There were large and significant declines in drug use and drug-related problems, and improvements in physical health with no group differences evident at 36 months. Despite improvements in global mental health, at both baseline and 36 months those with MD at baseline had significantly lower SF12 mental health scores. It was concluded that, with the exception of depression, the prognosis of depressed heroin users is not worse than that of non-depressed users.

Substitution treatment of injecting opioid users for prevention of HIV infection

BACKGROUND

Injecting drug users are vulnerable to infection with HIV and other blood borne viruses as a result of collective use of injecting equipment as well as sexual behaviour.

OBJECTIVES

To assess the effect of oral substitution treatment for opioid dependent injecting drug users on rates of HIV infections, and high risk behaviours.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and PsycINFO to March 2007. We also searched reference lists of articles, reviews and conference abstracts

SELECTION CRITERIA

Studies were required to consider the incidence of risk behaviours, or the incidence of HIV infection related to substitution treatment of opioid dependence. All types of original studies were considered. Two reviewers independently assessed studies for inclusion.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data from included studies, assessed quality and confirmed decisions by consulting with all other reviewers.

MAIN RESULTS

Thirty-three studies, involving 10,400 participants, were included. The majority were not randomised controlled studies and there were problems of confounding and bias. The studies varied in several aspects limiting the extent of quantitative analysis. Studies consistently show that oral substitution treatment for opioid-dependent injecting drug users is associated with statistically significant reductions in illicit opioid use, injecting use and sharing of injecting equipment. It is also associated with reductions in the proportion of injecting drug users reporting multiple sex partners or exchanges of sex for drugs or money, but has little effect on condom use. It appears that the reductions in risk behaviours related to drug use do translate into reductions in cases of HIV infection.

AUTHORS' CONCLUSIONS

Oral substitution treatment for injecting opioid users reduces drug-related behaviours with a high risk of HIV transmission, but has less effect on sex-related risk behaviours. The lack of data from randomised controlled studies limits the strength of the evidence presented in this review.

Injecting and Noninjecting Heroin Administration: Transitions and Treatment Outcomes across 36 Months

To examine long-term stability in route of administration and treatment outcomes for noninjecting (NIHU) and injecting (IHU) heroin users, a cohort of 429 heroin users were followed over 36 months. Across follow-up, 35.3% of NIHU injected heroin and a transition to primary heroin injecting was made by 8.5%. Amongst IHU, 11.1% smoked heroin and a transition to primary heroin smoking was made by 2.3%. While NIHU were less likely to be in treatment at 36 months, there were no differences in overall treatment exposure. At 36 months, there were no differences in heroin use, polydrug use, crime, physical health, or psychopathology. NIHU were, however, less likely to be injecting and to have injection-related health problems. It is concluded that there is a substantial risk of injecting occurring amongst NIHU and that route of administration does not differentially predict long-term treatment response.

The impact of treatment on 3 years' outcome for heroin dependence: findings from the Australian Treatment Outcome Study (ATOS)

AIM

To examine the impact of treatment for heroin dependence on drug use, injection-related risk-taking, health problems, criminality and general physical and mental health over 3 years among heroin-dependent Australians.

DESIGN

Longitudinal prospective cohort study.

PARTICIPANTS

A total of 615 heroin users enrolled in the Australian Treatment Outcome Study; 94.5% of the sample completed at least one follow-up interview over 36-month follow-up.

FINDINGS

The proportion who reported using heroin in the preceding month continued to decrease significantly from baseline to 24-month follow-up (99% versus 35%), with this rate remaining stable to 36-month follow-up. The reduction in heroin use was accompanied by reductions in other drug use. There were also substantial reductions in risk-taking, crime, injection-related health problems and improvements in general physical and mental health. Positive outcomes were associated with more time in maintenance therapies and residential rehabilitation and fewer treatment episodes. Time spent in detoxification was not associated with positive outcomes. Major depression was also associated consistently with poorer outcome.

CONCLUSIONS

At 3 years, there were impressive reductions in drug use, criminality, psychopathology and injection-related health problems following treatment exposure.

Patterns of sustained heroin abstinence amongst long-term, dependent heroin users: 36 months findings from the Australian Treatment Outcome Study (ATOS)

AIMS

To determine patterns of past month, 12 month and sustained 36 month heroin abstinence.

METHODS

As part of a longitudinal cohort study, 429 heroin users re-interviewed at 36 month follow-up for the Australian Treatment Outcome Study (ATOS).

RESULTS

The proportion who had sustained heroin abstinence since baseline declined from 14% at 12 months to 8% at 36 months. The proportion who reported abstinence over the preceding 12 months, however, increased significantly from 14% at 12 months to 40% at 36 months. There were no significant gender differences in the proportions reporting sustained 36 month abstinence. Females, however, were significantly more likely to have maintained abstinence over the 12 months preceding 36 month follow-up. Independent predictors of sustained abstinence over 36 months were fewer treatment episodes since baseline, not committing crime at baseline and higher levels of global psychological distress.

CONCLUSIONS

Despite a decline in the proportion who had maintained complete heroin abstinence over 36 months, there were substantial increases in 12 month abstinence patterns. The results illustrate the importance of stable treatment retention.

The Australian Treatment Outcome Study (ATOS): what have we learnt about treatment for heroin dependence?

Opioids make the single largest contribution to illicit drug-related mortality and morbidity worldwide In this paper we reflect upon what has been learnt regarding treatment outcome and the natural history of heroin use from the Australian Treatment Outcome Study (ATOS). We focus on what we knew prior to ATOS, what ATOS revealed that is novel, and the implications for research, practice and policy. ATOS provided strong evidence for sustained improvement attributable to treatment across the three years of the study. It is argued that treatment for heroin dependence is money well spent, and leads to clear and sustained benefits to both heroin users and society.