Scottish Government

Reduce the number of individuals with problem drug use

DESCRIPTION:

Estimates the numbers of people (aged 15 to 64 years) in Scotland who use opiates (including illicit and prescribed methadone) and/or benzodiazepines in 2012/13. The same study was last conducted in 2009/10 and before that in 2006.

Studies were carried out to estimate prevalence in 2000 and 2003 amongst those aged 15-54 years.

SOURCE:

2012/13 estimates (Revised)

Source: Estimating the National and Local Prevalence of Problem Drug Use in Scotland 2012/13 (Revised), NSS Information Services Division (ISD) Scotland

http://www.isdscotland.org/Health-Topics/Drugs-and-Alcohol-Misuse/Publications/

2009/10 estimates

Source: Estimating the National and Local Prevalence of Problem Drug Use in Scotland 2009/10, NSS Information Services Division (ISD) Scotland

http://www.isdscotland.org/Health-Topics/Drugs-and-Alcohol-Misuse/Publications/

2006 estimates:

Source: Estimating the National and Local Prevalence of Problem Drug Misuse in Scotland, Centre for Drug Misuse Research, University of Glasgow.

http://www.drugmisuse.isdscotland.org/publications/local/Prevalence_2009.pdf

2003 estimates:

Source: Estimating the National and Local Prevalence of Problem Drug Misuse in Scotland, Centre for Drug Misuse Research, University of Glasgow Scottish Centre for Infection and Environmental Health.

http://www.drugmisuse.isdscotland.org/publications/local/prevreport2004.pdf.

2000 estimates:

Source: Estimating the National and Local Prevalence of Problem Drug Misuse in Scotland Centre for Drug Misuse Research, University of Glasgow Scottish Centre for Infection and Environmental Health.

http://www.drugmisuse.isdscotland.org/publications/local/Prevalence.pdf

The evidence source is treated by NHS ISD Scotland as an official statistic.

The 2000, 2003, 2006, 2009/10 and 2012/13 estimates were produced using an internationally recognised capture-recapture methodology, where the data are available. The methodology relies upon re-sampling a population of unknown size to estimate its size from the number of individuals who appear in more than one sample. Essentially, the more often the same individuals appear in successive samples the smaller the unknown population is likely to be.

Data are collected from 4 data sources:

1) Clients registering with specialist drugs services

• The Scottish Drug Misuse Database
• Drug Treatment Services

2) Drug-related hospital admissions

• Hospital admissions data

3) Police reports to the Procurator Fiscal under the Misuse of Drugs Act (individuals with problem drug use only)

• Scottish Police Forces

4) Criminal Justice Social Work reports mentioning opiates and/ or benzodiazepines

• Criminal Justice Social Work reports

The data are analysed to produce estimates of the number of people with problem drug use at a variety of geographical levels including:

• Council area
• NHS Board area
• Alcohol and Drug Partnership area
• Former Scottish Police Force area.

The estimates are also broken down by gender and age (males only, as the numbers for females are too small).

The validity, reliability and precision of any drug prevalence estimation method are important issues. The study employs the 'capture recapture' methodology (involving log-linear modelling). The capture-recapture methodology explicitly models various relationships and dependencies between data sources and to an extent between different genders and age groups. For a given set of data, differing estimates can be obtained and these estimates are evaluated in terms of validity and precision. Statistical techniques have been developed to maximise the validity of capture-recapture methods, such as undertaking sensitivity analyses. The study used the 'boot-strapping' process to achieve 95% confidence intervals.

For more information on the methodology employed in these studies, please see:

http://www.isdscotland.org/Health-Topics/Drugs-and-Alcohol-Misuse/Publications/

Table 1: Estimated numbers of people with problem drug use (opiates and/or benzodiazepines): Scotland 2000, 2003, 2006, 2009/10 and 2012/13 (Revised).

* The age range was changed for the 2006 and 2009-10 estimates to bring them in line with European statistical requirements and to assist in making UK and international comparisons.

** The 2012/13 and 2009/10 estimates are for financial year, whilst the 2000, 2003 and 2006 estimates were for calendar year. The change to financial year was made to bring the estimates in line with other available information sources on drugs (e.g. Scottish Crime and Justice Survey and Scottish Drug Misuse Database) and also to align them with the reporting format of the other UK administrations.

*** A revised set of estimates for 2012/13 was published on 4 March 2016 using updated treatment data for the City of Glasgow and East Renfrewshire.  Data used to produce the estimates in the original publication (October 2014) was later found to have been incomplete.

DEFINITIONS:

In the context of these estimates problem drug use is defined as the problematic use of:

• Opiates (including heroin and prescribed and illicit methadone) and/or
• Benzodiazepines illicitly

It implies routine and prolonged use as opposed to recreational and occasional drug use.

The definition used for the 2012/13 estimates is consistent with that used for the earlier estimates.

Age range: Estimates for 2006, 2009/10 and 2012/13 are based on those between 15 and 64 years of age. Historical estimates (for 2000 and 2003) were for those aged between 15 and 54 years.

BASELINE AND PAST TRENDS:

The baseline year is 2006 as this is the last data point before the first term of the current administration. The baseline figure is an estimated 55,300 individuals with problem drug use.

Estimated number of people with problem drug use (opiates and/or benzodiazepines): Scotland 2000, 2003, 2006, 2009/10 and 2012/13 (Revised)

CRITERIA FOR RECENT CHANGE ARROW:

This evaluation is based on: any difference within +/- 2% per annum suggests that the position is more likely to be maintaining than showing any change. A decrease of 2% per annum or more suggests the position is improving; whereas an increase of 2% or more per annum suggests the position is worsening. The threshold of 2% per annum chosen is based on an assessment of the data available at this time, and may need to be reviewed as more information becomes available in the future.

For information on general methodological approach, please click here.

FUTURE ISSUES OR REVIEWS:

A review of the methodology is taking place prior to commissioning the work to derive the 2015/16 estimates.

ASSOCIATED TARGET:

Reduce the number of individuals with problem drug use in Scotland.