Summary
This study shows the continued effectiveness of primary care opiate substitution treatment in reducing mortality and harm to opiate users after a period of 11 years, and at delivering full recovery and drug-free discharge, as well as medically-assisted recovery.
There was a strong association in the study between social functioning and mental and physical health, suggesting that intervention in any one of these areas may have extended benefits by impacting on related variables. Clinical depression in particular is common in this group, and treatment may positively impact on other areas to produce better outcomes.
Employment also appears to be a strong predictor of favourable outcomes. The best predictor of a drug-free discharge was continuous uninterrupted treatment.
Strengths and limitations
This was a prospective, longitudinal, cohort study. It is a naturalistic study over 11 years, using 123 participants undergoing clinical treatment outside a research setting, and is the most extended study of its kind in a UK primary care setting. It used a well-validated research instrument, the OTI, which had previously been shown to have excellent psychometric properties. It is one of very few studies specifically investigating how recovery capital may influence recovery outcomes. The ‘social functioning’ section of the OTI addresses many, but not all, of the important facets of ‘recovery capital’; notably, cultural capital and physical capital are not included within this domain. The study team was necessarily limited by the domains of the validated instruments available at the outset of this study, of which the OTI was the best established and validated in terms of measurement of biopsychosocial outcomes. Over the 11 years of the cohort study, there was variable recording of urine test data within the clinical records, so it was not possible to triangulate self-reported drug-use data, as measured by the OTI instrument.
This study originally had a cohort of 123 patients, and it was estimated that 50 patients would be required to show a treatment effect. Only 27 (21.9%) were lost to follow-up, through dropping out of treatment, or never entering treatment. However, it was not possible to follow-up patients that had moved away from Sheffield. The term ‘medically-assisted recovery’ is a consensus statement derived from a government strategy document and widely used elsewhere in the literature.5 However, a broader definition is commonly used by specialists within the field, which recognises that service users may engage and disengage with opiate substitution treatment over a long period of time, and may continue some illicit drug use and still experience a continued improvement in health and social functioning.
Like other studies of this kind, it is not possible to use a randomised design or to have a control group of untreated patients.
Comparison with existing literature
Twenty-seven (22%) of the patients who entered the clinic in 1999 went on to achieve a drug-free discharge, 31 (25.2%) were still in treatment in medically-assisted recovery in primary care, and seven (5.7%) in secondary care. This represents a total of 65 (52.9%) patients achieving either a drug-free discharge or being retained in medically-assisted recovery. Only 21.9% of patients permanently dropped out (loss of contact and/or death and/or prison) of treatment, which is low compared to some other studies that report dropout rates as high as 40%.1,13,19 This suggests that long-term opiate substitution treatment in a primary care setting is effective at delivering low mortality, medically-assisted recovery, and drug-free discharge over an extended follow-up period.
The main predictive factor of a drug-free discharge is continuous treatment, whereas multiple exits and re-entries to treatment are more likely to lead to the patient remaining in treatment long term.20 Failing to retain patients in treatment effectively is likely to lead to poor outcomes and more patients in extremely long-term treatment. This should be considered by commissioners of opiate substitution treatment services, since the introduction of ‘any willing provider’ on relatively short-term contracts (UK Health and Social Care Act 2012) may adversely impact on outcomes, owing to discontinuity of multidisciplinary service provision.21
At 11 years of medically-assisted recovery, there were highly significant reductions in heroin, opiate, tranquilliser, and tobacco use among the follow-up patients. There were also reductions in polydrug and illicit polydrug use. There was an increase in alcohol use, which is documented in other studies.22,23 The significant reduction (P = 0.017) in concomitant use of tranquillisers is important, as concomitant benzodiazepine use with heroin is implicated in a significant proportion of deaths from drug misuse.24 Overall, there were no significant increases in any drug category, and reductions of over 98% in heroin and opiate use.
There was significant improvement in all areas of psychosocial and health outcomes, except sexual risk behaviour. Previous studies have suggested that effective methadone maintenance treatment paves the way for subsequent improvements in physical and psychological comorbidities,25 and the reductions of over 50% in GHQ and general health scores reflect this within the present study, with P-values all less than 0.001. In terms of medically-assisted recovery, the 97% reduction in injecting risk scores is extremely important,26 and shows the effect of treatment on drug use and injecting habits. At baseline, 31 out of 33 patients were using heroin, with 28 out of 33 injecting, compared with 5 out of 33 using heroin and 1 out of 33 injecting at follow-up.
There were very high levels of depression and anxiety at entry, with 45.5% of patients fulfilling diagnostic case criteria for depression. These comorbidities are known to have a negative effect on patients’ functioning and perceived quality of life.27–29 The results at follow-up show significant reductions in the prevalence of these disorders, and this highlights the association between opiate substitution treatment and reductions in psychological distress.
There was a very strong correlation between the three psychosocial outcomes (social, GHQ, general health) both at baseline and at follow-up.
These variables serve as indicators in other key areas, and high scores across the psychosocial variables are indicative of a high-risk patient. If a patient is experiencing distress or dysfunction in any of these areas, it is highly likely that they will also have higher scores in the other two.
The results also show that there is a strong association between employment and psychosocial functioning scores, such that employed people were more likely to have better physical health, and significantly better mental health and social functioning than unemployed people.
Implications for research and practice
To achieve a drug-free discharge and full recovery, patients should be retained in uninterrupted treatment where possible.
Psychosocial interventions should seek to improve patients’ mental, physical, and social functioning, including employment, in order to maximise their recovery capital.
Services should measure psychological functioning, as depression in particular is common and treatment may positively impact on other areas to produce better outcomes. This warrants further research.
