Methadone treatment in the Scottish context: outcomes of a community-based service for drug users in Lothian

Abstract

Few studies investigating the effectiveness of methadone treatment for opiate dependence have emanated from the UK. The core feature of treatment offered by Lothian Health’s Community Drug Problems Service involves the prescribing of methadone by the client’s general practitioner. Of a cohort of 494 daily users of opiates attending the service, 39% remained in treatment for at least 12 months. Up to 2 years in-treatment follow-up revealed significant improvement in injecting and criminal behaviour. There were no HIV seroconversions reported during the treatment period. There was no improvement in injection equipment sharing, condom use, illicit drug use or employment status. ‘Satisfactory’ discharge was achieved for 40% of those in treatment for at least 6 months. These results are largely consistent with the outcomes of methadone programmes elsewhere.

Introduction

By December 1996 a cumulative total of 1167 people in the Scottish region of Lothian (whose main urban centre is the city of Edinburgh) had been tested positive for human immunodeficiency virus (HIV) antibody, representing 46% of all individuals in Scotland known to have been infected (Scottish Centre for Infections and Environmental Health, 1997). A total of 52% of these became infected as a result of injecting illicit drugs with contaminated equipment.

Awareness of the extent of the epidemic among intravenous drug users (IDUs) in the region in the mid-1980s prompted the establishment of a range of health, education and social services with the expressed aim of preventing further transmission of the virus. The Community Drug Problems Service (CDPS), the subject of this study, was established in 1988 and represents one element in Lothian Health’s HIV prevention strategy. The service adopted a hierarchy of goals consisting of: (i) recruiting and retaining drug users in treatment; (ii) seeking to influence those in treatment to avoid equipment sharing and unsafe sexual practices; (iii) discouraging injecting, (iv) discouraging illicit drug use; and (v) encouraging, where appropriate, the adoption of a drug-free lifestyle. This approach is broadly in keeping with the harm reduction model of service provision for drug users (O’Hare et al., 1992) which has gained wide international support with the advent of the HIV epidemic and which has been advocated as best practice by the UK government-commissioned Advisory Council on the Misuse of Drugs (Department of Health and Social Security, 1988).

In seeking to achieve these goals the CDPS developed a relatively novel, shared care approach with general practitioners (GPs) in Lothian (Greenwood, 1990). The core feature of treatment offered to opiate dependent clients is the prescribing of methadone by the GP following assessment by the CDPS team, who in turn provide parallel drug monitoring, counselling and other specialist support services. Some clients with a complex clinical presentation receive their prescriptions centrally from the drug team. By 1995, 79% of general practices in Lothian were involved in prescribing oral substitute medication to a total of 1508 drug users (Bury, 1996).

Methadone maintenance (MM) has been the subject of more research than any other treatment for opiate addiction (Ball and Ross, 1991, Ward et al., 1992, Farrell et al., 1994). Although there is not a consensus regarding its effectiveness and underlying premises, most contemporary reviewers of the literature have concluded that it is a treatment of considerable efficacy. It is more effective than other treatments in achieving high treatment retention rates and is associated with benefits in the areas of illicit opiate use, criminal involvement and employment status, especially where treatment lasts at least 12 months. MM clients tend to relapse quickly if they drop out of treatment.

With regard to HIV risk behaviour and infection, several studies have reported improvements in injecting drug use and equipment sharing (Selwyn et al., 1987, Ball et al., 1988) and lower rates of HIV seroconversion (Blix and Gronbladh, 1988Chaisson et al., 1989) among MM clients compared to those not receiving the treatment, although none of these have been fully controlled trials. More recently, Caplehorn and Ross (1995)have presented evidence that MM is associated with a reduced likelihood of injecting drug use rather than less risky methods of injecting. In contrast to injecting risks, Ward et al. (1992)have concluded from their review of the literature that MM has not been shown to have any beneficial effects in the area of sexual risk reduction.

However, the vast majority of outcome research on MM originates from the United States where programmes are structured to fulfil relatively circumscribed federal government requirements. Although MM treatment in the UK is widespread, few research studies have described how the treatment is administered, or investigated its efficacy. Programmes in the UK exist in the absence of a statutory regulatory structure and their administrative procedures are not standardised (Farrell et al., 1994). The repeated finding that MM programmes vary greatly in their relative effectiveness, even within the more controlled US environment, indicates that research comparing outcomes of diverse programmes in the UK is a priority.

The present study provides a description of the administrative procedures of the drug service in Lothian and data pertaining to outcomes up to 2 years in treatment and at discharge.