Drug-related deaths in Scotland in 2010

2 Data sources

2.1 The National Records of Scotland (NRS) - formerly General Register Office for Scotland (GROS) holds details of all deaths which are registered in Scotland. By convention, deaths are counted on the basis of the calendar year in which they are registered rather than the year of occurrence (as the latter might not be known). NRS closes its statistical database for a calendar year about five or six months after the end of the calendar year. The statistics for 2010 are based upon the information which NRS had obtained by the end of May 2011. NRS classifies the underlying cause of each death using International Statistical Classification of Diseases and Related Health Problems (ICD) codes, based on what appears in the medical certificate of the cause of death together with any additional information which is provided subsequently by (e.g.) certifying doctors, pathologists and Procurators Fiscal.

2.2 Drug-related deaths are identified using details from the death registrations supplemented by information from a specially-designed questionnaire, which is completed by forensic pathologists and lists the drugs and solvents that were found. NRS requests this information for all deaths involving drugs or persons known, or suspected, to be drug-dependent. Additionally, NRS follows up all cases of deaths of people where the information on the death certificate is vague or suggests that there might be a background of drug abuse. This enhancement to the data collection system was described in a paper published by NRS in June 1995 (Annex C: References). A copy of the questionnaire used with effect from 2008 is in Annex D. In the case of deaths which involved drugs which are available on prescription, it should be noted that NRS does not know whether those drugs had been prescribed to the deceased: such information is not collected by the death registration process nor by the pathologists' questionnaires. Therefore, NRS does not know how many of the deaths which involved (say) methadone were of people who had been prescribed the drug (some information about this is available from the NHS report referred to above paragraph B9 of Annex B).

2.3 The questionnaire was revised for 2008, in order to collect more complete information about the substances present in the body. This caused a break in the series of figures for 'drugs reported'.

The discontinuity arose because:

pre-2008, the form asked about the 'principal drug or solvent found in a fatal dose' and about 'any other drugs or solvents involved in this death' - so some pathologists reported only the substances which, they believed, contributed directly to each death;
now the form asks about the drugs or solvents 'implicated in, or which potentially contributed to, the cause of death' and about 'any other[s] � which were present, but which were not considered to have had any direct contribution to this death'- so some pathologists now report substances which they would not have mentioned previously.

2.4 NRS's data from the questionnaires for 2008 onwards distinguish between (a) drugs which were implicated in, or which potentially contributed to, the cause of death and (b) any other drugs which were present, but which were not considered to have had any direct contribution to the death. As a result, NRS can produce figures for 2008 onwards:

(i) on the 'drugs which were implicated in, or which potentially contributed to, the cause of death' basis - i.e. counting only drugs which were reported under (a); and
(ii) on the 'all drugs which were found to be present in the body' basis - i.e. covering drugs which were reported under either (a) or (b).

Following consultation with the National Forum on Drug-related Deaths in 2009 and 2010, 'drugs which were implicated in, or which potentially contributed to, the cause of death' became the standard basis for the figures for 2008 onwards that NRS produces for individual drugs.

2.5 It should be noted that:

the introduction of the new questionnaire caused a break in the series of figures for individual drugs between 2007 and 2008. This is because, in 2007 and earlier years, some pathologists reported, in the old questionnaire, all the drugs that they found (i.e. not just the drugs that they believed were implicated in, or contributed to, the cause of death) - so they provided information on the 'all drugs which were found to be present in the body' basis (i.e. not on the new standard basis); and
the change in the basis of the figures for individual drugs has not affected the overall total number of drug-related deaths - it has just reduced the number of drugs which are counted, for the purpose of the standard figures, for some deaths.

2.6 Users of the statistics are reminded that:

in this publication, Table 3 and Table Y provide figures for 2008 to 2010 on the standard basis, Tables HB3 and C3 give figures for 2010 on the standard basis, and Table 6 shows the figures for 2010 on the two bases;
alternative versions of Tables HB3 and C3, giving figures for 2009 and 2010 on the 'all drugs which were found to be present in the body' basis, are available on the web site (which makes it clear that they are not on the standard basis).

2.7 More information about the change (including why NRS cannot produce figures on the standard basis for 2007 or earlier years) is available in the previous edition.

2.8 The statistics of drug-related deaths may be affected by other differences, between years and/or between areas, in the way in which the information was produced. For example:

technical advances may enable the detection of small quantities of substances that could not have been found in the post-mortems that were performed several years ago;
the range of substances for which tests are conducted may change - e.g. for a number of years, a laboratory did not routinely test for the presence of cannabis (because the view was that, in general, it did not contribute to causing deaths), but now does so more often, because Procurators Fiscal are now more likely to want to know whether the deceased had been using it. More generally, advice is that there is a demand to obtain more complete and thorough toxicology on all cases tested for drugs, which includes fuller examinations for, and hence a greater possibility of finding, more drugs; and
pathologists in one area report any findings of benzodiazepines by referring to that group of drugs unless they are sure that only one particular benzodiazepine (e.g. diazepam) was used, so the areas which they serve appear to have low proportions of deaths for which diazepam is mentioned (compared to areas where diazepam is more likely to be named specifically, and where there are proportionately fewer reports of benzodiazepines as a group).

previous | contents | next