Treatment outcomes for methamphetamine users receiving outpatient counselling from the Stimulant Treatment Program in Australia

Authors


Rebecca McKetin BSc (Psychol) Hons, PhD, Fellow, Adrian J. Dunlop MB BS, GradDipEpi&Biostat PhD, FAChAM, Area Director and Senior Staff Specialist, Addiction Medicine, Rohan M. Holland Bachelor of Nursing, Research Officer, Rachel A. Sutherland BSocSc (Criminology) (Hons), Research Officer, Amanda L. Baker BA (Hons), MPsych, PhD, Professor, Allison M. Salmon BPsych, MPH, PhD, Senior Research Assistant, Susan L. Hudson BSocWk, MSW, PhD, Senior Clinician, Alcohol and Drug. Dr Rebecca McKetin, Centre for Research on Ageing, Health and Well-being, The Australian National University, ACT 0200, Australia. Tel: +61 2 61258407; Fax: +61 2 61251558; E-mail: rebecca.mcketin@anu.edu.au

Abstract

Introduction and Aims. The purpose of this study was to document treatment outcomes for methamphetamine users receiving outpatient counselling from the Stimulant Treatment Program (STP) in Australia.

Design and Methods. Clients attending the STP for methamphetamine use (n = 105) were assessed on entry to the service and at 3 (n = 86) and 6 months (n = 83) after starting treatment. At each interview methamphetamine use (days of use, severity of dependence), other drug use and health and social functioning (HIV risk behaviour, crime, disability, psychotic symptoms and hostility) were assessed for the past month.

Results. Participants received a median of six counselling sessions (interquartile range 1–11) over a period of 89 days (interquartile range 41–148 days). Past month methamphetamine use fell from 79% at treatment entry to 53% at the 3-month follow-up (P < 0.001) and 55% at the 6-month follow-up (P < 0.001). There were statistically significant reductions in psychotic symptoms, hostility and disability associated with poor mental health. There was no change in other drug use, crime or HIV risk behaviour. Reductions in methamphetamine were more common among younger participants, those who had no history of drug treatment and those without concurrent heroin use.

Discussion and Conclusions. Methamphetamine users entering the STP showed reductions in methamphetamine use and improvements in their mental health after treatment. Improved treatment responses are needed to address polydrug use and other harms within in this population.[McKetin R, Dunlop AJ, Holland RM, Sutherland RA, Baker AL, Salmon AM, Hudson SL. Treatment outcomes for methamphetamine users receiving outpatient counselling from the Stimulant Treatment Program in Australia. Drug Alcohol Rev 2013;32:80–87]

Introduction

Illicit methamphetamine use is a substantial and growing global public health concern [1,2] which is costly to both society and the individual [3]. Australia has one of the highest rates of methamphetamine use in the world with 2.1% past year prevalence [4]. It has been estimated that there are 97 000 Australians dependent on stimulant drugs (0.6% of 19–85-year-olds) [5], with this largely driven by methamphetamine injection [6]. Methamphetamine use accounts for 86% of stimulant users presenting to drug treatment, with treatment demand for cocaine and ecstasy being comparatively low [7].

Specialised treatment options for methamphetamine use in Australia are scarce, a picture that is not dissimilar to most other parts of the world. This situation partly reflects a limited evidence base. While there have been a number of treatment trials in this area [8–14], there are no readily scalable effective treatment interventions for methamphetamine dependence [1,15–17]. A recent meta-analysis of psychological/behavioural treatments for methamphetamine use concluded that there was no clear evidence that these types of interventions, as a group, were more effective than passive or minimal treatment interventions in reducing use [1]. Efforts to find a pharmacotherapy to treat methamphetamine use remains largely in the preclinical and clinical trial stages [18,19].

In the mean time, treatment for methamphetamine use in Australia is provided through generic community-based drug treatment services, with outpatient counselling the most common treatment modality [20]. A limitation of this approach is that these services are typically tailored toward alcohol or opioid dependence, and are perceived by methamphetamine users as not meeting their needs [21]. This problem has been evident both in Australia and internationally [21,22]. Consequent low treatment coverage has been a problem, with the majority of dependent users in the community not having ever received treatment for their methamphetamine use [23].

In response to growing demand for methamphetamine treatment in Australia in the early 2000s, the New South Wales (NSW) government established two dedicated clinics, referred to as the Stimulant Treatment Program (STP) [24]. These clinics, established in 2006, provide outpatient counselling, in conjunction with education and support, for clients and significant others. The clinical model involves a stepped-care approach that modifies the intensity and nature of the clinical intervention according to the severity of the problem and goals of the client [25]. Clients are referred to ancillary services for specific health issues (e.g. psychiatric consultation, sexual health clinics).

The aim of this study was to document the treatment outcomes for methamphetamine users who received outpatient counselling from the STP at 3 and 6 months after they started treatment. Outcomes considered were methamphetamine use, polydrug use, criminal involvement, HIV risk behaviour, level of disability associated with poor physical or mental health, psychotic symptoms and hostility. We also examined what client characteristics were associated with reductions in methamphetamine use, to determine whether this type of outpatient counselling service was more or less suited to particular types of clients.

Methods

Treatment protocol

The clinical protocol used at the STP involved a structured intake, assessment and treatment process. Counselling was tailored to the goals of the client, using a stepped-care approach, and was carried out within a harm-minimisation framework. Being a community-based treatment service, clinicians were free to adopt various therapeutic approaches (e.g. motivational interviewing, cognitive behaviour therapy, mindfulness and narrative therapy) depending on their preference and the needs of the client. For further detail on the clinical protocol see Appendix S1.

Participants

Participants in the current study were selected from a larger evaluation of the STP [24], for which clients were recruited from the two STP clinics from September 2008 to January 2010. These clinics are located in Sydney (St Vincent's Hospital Alcohol and Drug Service) and Newcastle (the Hunter New England Local Health District). Inclusion criteria for the STP evaluation were being: (i) 18+ years of age; (ii) fluent in English; (iii) willing to participate; (iv) not having been incarcerated in the past month (in order to establish a naturalistic pre-treatment measure of drug use); and (v) not having previously attended the STP (to exclude clients who were returning to the service for follow-up care). Clients entering the service were contacted consecutively (either face-to-face or by phone) and invited to participate in the study. Not all clients could be contacted because of staffing constraints. Of the 213 new clients who presented during the evaluation period, 148 were included in the STP evaluation (Figure 1); the characteristics of this sample did not differ significantly from new clients entering the STP during the evaluation period (see Appendix S2). From this sample participants were excluded from the current study if they were not seeking treatment for methamphetamine use, had received dexamphetamine substitution therapy as part of their treatment at the STP, or if they had received drug treatment from services outside of the STP during the follow-up period (Figure 1).

Figure 1.

Recruitment of STP clients into the study. a Transferred to other services or could not be contacted after intake. STP, Stimulant Treatment Program.

Procedure

Participants were interviewed on entry to treatment (baseline) and again at 3 and 6 months after starting treatment. Data were collected using a structured questionnaire that was administered by a trained interviewer who was independent of the STP clinical service. Baseline interviews were conducted face-to-face either on or soon after the first day of treatment (median of 0 days from treatment entry, interquartile range 0–6 days). When measures of drug use, health and social functioning were assessed at baseline, participants were asked to report for the month prior to treatment entry. Participants were re-interviewed at 3 months (median 98 days, interquartile range 90–106) and 6 months (median 188 days, interquartile range 179–201) after starting treatment. Follow-up interviews were conducted via telephone, except where a face-to-face interview was more convenient. Interviews took approximately 30 min to complete. Detailed contact information was obtained at the baseline interview to facilitate follow up.

All participants were volunteers who provided informed consent prior to participation. Participants were offered a $10 gift voucher for completing the baseline interview and a $30 gift voucher for completing each follow-up interview. The project was approved by the Hunter New England Area Health Service Human Research Ethics Committee and was ratified by the St Vincent's Hospital Human Research Ethics Committee.

Measures

Demographic information, years of methamphetamine use and main route of methamphetamine use were collected at the baseline interview. Drug use, health and social functioning were assessed at each interview using the measures described below.

Drug use, crime and HIV risk.  Drug use, crime and HIV risk were assessed using the Opiate Treatment Index, which is a validated measure of drug use and related harms that covers various drug classes [26]. Drug use measures included days of methamphetamine use in the past month and days of drug use for each other drug type in the past month. HIV risk behaviour measures were having been sexually active in the past month and having had unprotected casual sex in the past month. Crime was self-reported crime (drug dealing, property crime, fraud or violent crime) in the past month.

Severity of methamphetamine dependence.  Severity of methamphetamine dependence was measured using the Severity of Dependence Scale (SDS), which yields a score from 0 to 15 [27]. The SDS has been validated in samples of stimulant users in Australia and in the UK [27,28]. Dependence was defined as a score of 4+ on the SDS, which corresponds to a DSM-IV diagnosis of dependence with 71% sensitivity and 77% specificity [28].

Psychotic symptoms and hostility.  Psychotic symptoms and hostility were measured with the Brief Psychiatric Rating Scale (BPRS) [29]. The BPRS is a semi-structured psychiatric assessment tool that assesses the severity of various psychiatric symptoms. Scores on BPRS items range from 1 to 7; scores of 4+ signify clinically significant symptoms [29]. Psychotic symptoms were defined as a score of 4+ on any of the BPRS items of hallucinations, unusual thought content or suspiciousness. Hostility was defined as a score of 4+ on the BPRS hostility item [29].

Disability.  Disability associated with physical and mental health was defined as a score below 40 on the Physical Component Scale and Mental Component Scale of the Short Form 12 respectively, corresponding to more than one standard deviation (SD) below the normative population mean [30].

Treatment exposure.  Measures were the number of counselling sessions received and the time spent in treatment (days from the start to the finish of treatment) during the 6-month follow-up period, as recorded in the NSW Health Community Health Information Management Enterprise system.

Statistical analysis

Data analysis was carried out using Stata Version 11.1. Medians and interquartile ranges are reported for skewed data. Post-treatment changes were assessed by comparing outcome measures at follow up with pre-treatment measures for the same participants using the Wilcoxon matched-pairs signed-ranks test for continuous variables [31] and the McNemar's exact test of symmetry for categorical variables [32]. Participants who reduced their methamphetamine use at 6 months (at least 50% fewer days than at baseline) were compared with participants who did not, using t-tests for normally distributed data, Kruskal–Wallis tests for skewed data and Pearson's χ2-tests for categorical outcomes. All tests were two-sided and significance was set at P < 0.05.

Follow up of the sample and attrition

Eighty-two per cent of participants were re-interviewed at 3 months after starting treatment and 79% were interviewed at 6 months. Follow up was more likely among participants who were injecting methamphetamine, more severely dependent on methamphetamine, using methamphetamine in the month prior to treatment, unemployed, not Aboriginal or Torres Strait Islander and not smoking tobacco (P < 0.05; see Appendix S3 for details).

Results

Characteristics of the sample

The mean age of the sample (n = 105) was 34 years (SD 8 years). The majority of participants were single (69%), male (76%) and unemployed (63%, cf. 24% full-time employment and 10% casual or part-time employment). The majority of the sample self-identified as being heterosexual (71%), with 19% homosexual and 9% bisexual (<1% other). Participants had a median of 10 years of schooling (interquartile range 7–12 years), 37% had a trade or technical qualification and 23% had completed a university degree. A minority were born outside of Australia (15%), 10% were from a non-English speaking background and 8% identified as Aboriginal or Torres Strait Islander. For 38% of participants, entry to the STP represented their first time in drug treatment.

Participants had used methamphetamine for a median of 8 years (interquartile range 3–15 years), most injected methamphetamine (69%, cf. 23% smoking, 9% snorting or swallowing). Participants had used methamphetamine on a median of 6 days in the past month (interquartile range 1–14 days), with 79% of participants having used during this time. Tobacco, alcohol and cannabis were the most commonly used other drugs (Table 1).

Table 1.  Drug use, health and social functioning at baseline, the 3-month follow up and the 6-month follow up
 Baseline3 months P-value6 months P-value
(n = 105)(n = 86)(n = 83)
  1. P-values based on a pair-wise comparison of follow-up and baseline scores. SDS, Severity of Dependence Scale.

Methamphetamine use in the past month     
 Any use (%)7953<0.00155<0.001
 Days of use (median)61<0.0011<0.001
 Severity of dependence (median SDS score)73<0.0012<0.001
 Dependent (%)7647<0.00139<0.001
Other drug use in the past month (%)     
 Tobacco78760.999750.999
 Alcohol61630.629690.108
 Cannabis43380.118420.824
 Heroin670.99960.999
 Cocaine1220.01670.508
 Ecstasy17100.791170.832
Health and social functioning in the past month (%)     
 Physical health disability27170.076230.263
 Mental health disability68500.00643<0.001
 Psychotic symptoms26120.024160.108
 Hostility41250.020230.020
 Injected5542<0.001460.001
 Injected with used needle760.99920.688
 Sexually active70650.383710.999
 Unprotected casual sex22160.581270.648
 Crime30240.701290.999

Mental health in the month prior to entering treatment was poor: the majority of participants (68%) reported disability associated with poor mental health, 41% reported clinically significant levels of hostility and 26% reported psychotic symptoms (Table 2). HIV risk behaviour was also common during this time: the majority of participants (70%) were sexually active, 22% had engaged in unprotected casual sex and 55% had injected drugs (Table 2).

Table 2.  Characteristics of participants who reduced their methamphetamine use at the 6-month follow up
Baseline sample characteristicsReduction in days of methamphetamine usea
No (n = 29)Yes (n = 41)
  1. **P < 0.01, *P < 0.05. Excludes participants who were followed up at 6 months but who did not report past month methamphetamine use at baseline (n = 13). aAt least 50% fewer days than at baseline. SDS, Severity of Dependence Scale.

Demographics  
 Age (mean)3833**
 Female (%)3120
 Not heterosexual (%)4529
 Married (%)3132
 Born outside Australia (%)712
 Non-English speaking background (%)310
 Aboriginal or Torres Strait Islander (%)47
 Years of school (median)1011
 Tertiary qualifications (%)4871
 Unemployed (%)6954
Methamphetamine use  
 Days of use in the past month (median)99
 Severity of dependence (median SDS score)89
 Dependent (%)8388
 Injecting (%)7673
 Years of use (median)128
Other drug use (%)  
 Tobacco6971
 Alcohol4573*
 Cannabis4151
 Cocaine320*
 Ecstasy1022
 Heroin140*
Health and social functioning (%)  
 Physical health disability3424
 Mental health disability6976
 Psychotic symptoms2129
 Hostility3146
 Crime3827
 Sexually active6973
 Unprotected casual sex2820
 Injected with used needle97
Treatment exposure  
 No. counselling sessions (median)77
 Duration of treatment (median days)11978
 First time in drug treatment (%)2449*
 Clinic site (Newcastle)6261

Treatment outcomes

During the follow-up period, participants received a median of six counselling sessions (interquartile range 1–11) and spent a median of 89 days in treatment (interquartile range 41–148 days).

Methamphetamine use.  There were significant reductions in all measures of methamphetamine use at both the 3- and the 6-month follow-up relative to pre-treatment levels (Table 1). Among participants who had used methamphetamine in the month prior to starting treatment (n = 83), 41% had not used in the past month at the 3-month follow up, and 39% had not used in the past month at the 6-month follow up. Within this group, reduced days of methamphetamine use in the past month (at least 50% fewer days than at baseline) were most likely among younger participants and those who had not been to drug treatment before (Table 2). This group also had different patterns of polydrug use, being more likely to drink alcohol and use cocaine, and not use heroin. Neither the number of counselling sessions received nor the time spent in treatment were associated with reductions in methamphetamine use at 6 months (Table 2).

Polydrug use.  There was a significant reduction in the proportion of the sample reporting cocaine use at 3 months after starting treatment relative to baseline but this effect was no longer present at the 6-month follow up. There was no significant reduction in the past month use of other drugs (Table 1).

Health and social functioning.  Participants showed significant reductions in psychotic symptoms, hostility and disability associated with poor mental health at both the 3- and 6-month follow up (Table 1). Physical health did not improve significantly, although levels of disability associated with poor physical health were low prior to treatment. There was no significant reduction in crime or sexual risk behaviour. Although injecting drug use decreased, there was no significant decrease in sharing used needles (Table 1).

Discussion

Methamphetamine users reported significant reductions in their methamphetamine use at 3 and 6 months after initiating outpatient counselling at the STP. They also reported significant reductions in psychotic symptoms, hostility and disability associated with poor mental health. Younger methamphetamine users who had not previously been to treatment were most likely to reduce their methamphetamine use, while older methamphetamine users with concurrent heroin use were least likely to respond to this form of treatment. With the exception of a concurrent reduction in cocaine use, outpatient counselling at the STP did not reduce polydrug use among methamphetamine users, nor did it reduce their HIV risk behaviour or crime.

There were specific clinical issues within this sample that indicate a need for specialised methamphetamine treatment. First, there were high levels of sexual risk behaviour in the sample, which did not reduce following treatment. Methamphetamine use can increase libido and the related impact on HIV risk is therefore a concern [1]. Although no effective treatment approaches have yet been found to reduce sexual risk behaviour among methamphetamine users [1], tailoring treatment to address this issue, as has been done in the USA [8], might be warranted in Australia. Second, a substantial proportion of the sample reported clinically significant psychotic symptoms and/or hostility (26% and 41% respectively in the month prior to entering the STP). A specialised treatment approach may be helpful in managing these comorbid psychiatric symptoms. A better evidence base for treating drug-induced psychotic symptoms, and hostility including the use of psychosocial interventions and/or prescription of anti-psychotic drugs in this context, is needed [33].

A potential downside to providing specialised care for methamphetamine use was the lack of a reduction in polydrug use. Methamphetamine users who attend generic drug treatment services appear to show reductions in their polydrug use alongside reductions in methamphetamine use [34]. However, this was not the case with the clients attending the STP, suggesting that the focus specifically on stimulants may have neglected other patterns of drug use. Ongoing polydrug use (particularly heroin use) may have been responsible for the lack of significant reductions in crime. While only a minority of the current samples were using heroin, this group were less likely to reduce their level of methamphetamine use after treatment.

Inconsistent with previous research, there was no relationship between the amount of counselling received by clients and post-treatment reductions in methamphetamine use [35]. This null finding is likely to reflect the stepped-care model used at the STP and the variation in the level of methamphetamine use seen among clients at the service. Rather than providing a fixed duration of treatment, the number of counselling sessions provided through the STP was tailored to the needs of the client, so that clients with low level use would receive only a brief intervention, whereas clients with more problematic methamphetamine use would stay in treatment for longer. In this sense, treatment exposure would be more likely to correlate with the intensity of the presenting drug problem, rather than client outcomes.

Methodological constraints

The lack of a no-treatment control group in the current study means that some of the post- treatment reduction in methamphetamine use may have been because of natural remission from drug use or other secular factors (e.g. reduced availability of methamphetamine [36]). There were a number of other methodological constraints. First, we did not use toxicology to verify self-reported drug use. However, self-reported drug use has been found to be reliable and valid [37]. Second, a proportion of participants were still in treatment at the time of the follow-up assessments and this may have bolstered 3- and 6-month outcomes. Third, attrition may have biased outcomes, although attrition was low, and there was no association between factors associated with attrition and those predictive of treatment outcomes. Finally, we were unable to measure the extent to which each clinician followed a particular intervention approach (e.g. cognitive behavioural therapy, mindfulness) and, therefore, we could not compare the relative effectiveness of such approaches. However, this heterogeneity is typical of clinical practice in the field, which is affected by the preferences of clinicians and tailored to meet the needs of each client.

Conclusion

In conclusion, clients receiving outpatient counselling at the STP show reduced methamphetamine use and improved mental health after treatment. This type of service was most suited to younger clients with no previous history of drug treatment. Conversely, it was less suited to older methamphetamine users, those with previous treatment attempts and those with comorbid heroin use; and, it failed to reduce polydrug use, HIV risk behaviour and crime.

Acknowledgements

This evaluation was funded by the Mental Health and Drug and Alcohol Office, NSW Health. The authors would like to thank the staff at each of the STP services for their support in referring clients to the evaluation, and for providing input on the interpretation of results. We also thank the clients of the services for participating in the evaluation study.

Ancillary