Hidden need for drug treatment services: measuring levels of problematic drug use in the North West of England

Abstract

With a multi-agency approach, established monitoring systems can be used to measure hidden populations of drug users. Estimates of the current populations of such users in the North West of England suggest that planned increases of people in treatment by 100 per cent would fail to accommodate even current level of problematic users. A holistic approach to new initiatives must ensure that the high level of relapse once drug users are discharged are reduced and that the needs of young users are addressed before prolonged treatment is required.

How well do trends in incidence of heroin use reflect hypothesised trends in prevalence of problem drug use in the North West of England?

“…It might be expected that PDU prevalence in the City of Manchester would decline, because current cessation rates amongst those that joined the PDU the population during the 1980s, when incidence was at its peak, may exceed current incidence rates. In this context it is interesting to compare the 2000-2001 prevalence estimate of 23.9 (95% CI 21.3-28.4) per 1000 population aged 16-54 years (Gemmell et al, 2004) with an estimate from a previous study (Beynon et al, 2001). Scaling the earlier estimate to a comparable age range (Gemmell et al, 2004) gives a prevalence rate of 31.0 (95% CI 26.2-37.1) per 1000 aged 16-54 years during 1997.…”

“…As in previous UK studies (Beynon et al, 2001;Hickman et al, 1999;Wood, Bloor, & Palmer, 2000), a problem drug user was defined as: 'A person who experiences social, psychological, physical, or legal problems related to intoxication and/or regular excessive consumption and/or dependence as a consequence of his/her own use of drugs or chemical substances' the definition was refined to include only users of opiates, cocaine and/or benzodiazepines. The estimates were obtained using multi-sample capture-recapture (C-RC), based on four samples of PDUs known to criminal justice or health care sources.…”

Estimating the Prevalence of Drug Use Using Mark-Recapture Methods

“…Other local estimates in the United Kingdom produced in the 1990s include Squires et al (1995) who produced an estimate for Liverpool, Beynon et al (2001) who compared and contrasted estimates across the North West of England (an area that experienced relatively high levels of opiate use in the early 1980s) and Brugha et al (1998) who applied the method in a more rural area. Elsewhere in the United Kingdom, studies estimated the prevalence of drug use in Northern Ireland (McElrath, 2002; and in Wales (Bloor, Wood and Palmer, 2000).…”

“…One used mark-recapture methods in Greater Manchester, updating previous estimates of the prevalence of opiate use (Beynon et al, 2001). Another used mark-recapture methods to estimate the prevalence of opiate use in Liverpool, Brighton and parts of Inner London (Hickman et al, 1992) and a third project used the multivariate indicator method (MIM) to estimate the number of opiate users in England (Frisher, Heatlie and Hickman, 2007).…”

Capture-recapture estimates of problem drug use and the use of simulation based confidence intervals in a stratified analysis

“…Within the UK, multi-sample capture-recapture has been applied to estimate the prevalence of problem drug in the north west of England, 11 London, 12 Liverpool, 13 Glasgow, 14 Dundee, 15 the north east of Scotland, 16 and, in one of few studies involving rural areas alone, Cheshire. 17 Outside the UK, the European Monitoring Centre on Drugs and Drug Addiction (EMCDDA) funded a study, using three sample capture re-capture methods, to estimate the prevalence of opioid misuse within six European cities for the age group 15-54.…”