4.1 Deaths are normally classified by geographical area on the basis of the usual place of residence of the deceased (or, if that is not known, or is outwith Scotland, on the basis of the location of the place of death). Table HB1 shows the numbers of drug-related deaths for each NHS Board area. Of the 584 deaths in 2011, 192 (33 per cent) were counted against the Greater Glasgow & Clyde NHS Board area. Lothian, with 73 (13 per cent), had the next highest total followed by Grampian (58 or 10 per cent) and Lanarkshire (52 or 9 per cent).
4.2 Because of the generally small numbers involved, particularly for some NHS Board areas, great care should be taken when assessing any apparent trends shown in the table. Year-to-year variation in the figures could result in apparently large percentage changes. This is more likely for the areas with smaller populations, but can also be seen sometimes in the figures for the more populous areas (e.g. Greater Glasgow & Clyde: 151 in 2004; 111 in 2005; 162 in 2006). Therefore, using 5-year moving annual averages should 'smooth out' the effects of any fluctuations, and so provide a better indication of the longer-term trends. The areas with the largest increases between their annual averages for 1997-2001 and 2007-2011 were Greater Glasgow & Clyde (up by 68, from 115 to 183), Lothian (up by 32, from 43 to 75), Lanarkshire (up by 27, from 22 to 49), Ayrshire & Arran (up by 23, from 16 to 39), Fife (up by 22, from 11 to 33) and Tayside (up by 21, from 20 to 41).
4.3 The table also shows the population of each NHS Board area, and what its average number of drug-related deaths per year (for 2007-2011) represented per 1,000 population (using the population in the middle of the 5-year period as a proxy for the average population over the whole period). For Scotland as a whole, the average of 529 drug-related deaths per year represented a rate of 0.10 per 1,000 population. The area with the highest rate was Greater Glasgow & Clyde (0.15), the next highest rates were for Ayrshire & Arran (0.11) and Tayside (0.10), and four areas (Fife, Grampian, Lanarkshire and Lothian) had rates of 0.09.
4.4 Table HB2 gives a breakdown by cause of death for each NHS Board area for 2011. Table HB3 shows some geographical differences in the reporting of certain drugs: figures which should be used with particular care, in the light of the points mentioned in sections 2 and 3.3, the effects of which could be proportionately greater on the figures of some of the areas with lower populations. Note also that the figures given in Table HB3 are on the standard basis (drugs implicated in, or which potentially contributed to, the cause of death), and so are not comparable to figures (in the editions for 2008 and earlier years) on the basis of 'all drugs which were [reported as having been] found to be present in the body'. As mentioned earlier, this web site has versions of Table HB3 which give (i) figures for 2008 on the standard basis and (ii) figures for 2009, 2010 and 2011 on the 'all drugs which were found to be present in the body' basis.
4.5 Table HB3 shows the drugs reported for NHS Board areas. Overall, heroin/morphine was believed to have been implicated in, or to have potentially contributed to, 35 per cent of the total number of deaths in 2011 - but for a noticeably above-average proportion in Tayside (23 out of 45) and for particularly low proportions in Grampian (13 out of 58) and Lothian (14 out of 73). Methadone was implicated in, or potentially contributed to, 47 per cent of drug-related deaths, and for an unusually high proportion in Lothian (42 out of 73) and a rather low proportion in Lanarkshire (20 out of 52). The table also shows that benzodiazepines were implicated in, or potentially contributed to, 83 per cent of the deaths in Grampian (48 out of 58), compared to 32 per cent for Scotland as a whole - although this comparison might be affected by the differences in reporting practices which are mentioned in section 2. Cocaine accounted for a relatively high proportion of the drug-related deaths in Grampian (11 out of 58), compared to 6 per cent for Scotland as a whole.
4.6 Table HB4 provides, for each NHS Board area, for a number of age-groups, the drug-related death rate per 1,000 population. As with the overall rates in Table HB1, the figures were calculated using the average number of drug-related deaths per year (for 2007-2011), by taking the population in the middle of the 5-year period as a proxy for the average population over the whole period. Even though the figures are five-year averages, they must still be used with caution for the less populated areas (e.g. just three 15-24 year old drug-related deaths in the five years from 2007 to 2011, inclusive, caused Shetland to have a death rate for that age-group which was double the rate for Scotland as a whole). Of the more populous areas, Greater Glasgow & Clyde had the highest drug-related death rates: 0.34 for 25-34 year olds and 0.39 for the 35-44 age-group; both well above the overall average rates for Scotland as a whole for the same 5-year period (0.27 and 0.24, respectively). Ayrshire & Arran, Fife, Grampian and Tayside had rates for 25-34 year olds which were above-average (0.32, 0.31, 0.29 and 0.29, respectively), but their rates for the 35-44 age-group were much lower, with the exception of Tayside (0.26, 0.21, 0.17 and 0.28) and, in some cases, were below the average level for Scotland as a whole for the five years. Greater Glasgow & Clyde's death rate for 45-54 year olds was 0.16, well above the overall level of 0.10, which also happened to be higher than the figure for any of the other areas. However, the pattern was less clear for the 15-24 age-group, for which several areas had death rates which were above the overall average level for Scotland for the five years.