3.1.1 On the basis of the definition used for these statistics, there were 574 drug-related deaths in 2008, 119 (26 per cent) more than in 2007 and 325 (131 per cent) more than in 1998. The figures in Table 1 show that the number of drug-related deaths has risen in eight of the past ten years: the long-term trend appears to be steadily upwards.
3.1.2 However, the statistics also show some year to year fluctuations. For this reason, moving annual averages are likely to provide a better guide to the long-term trend than the change between one year and the next. Figure 1 illustrates this:
Clearly, individual years' figures tend to fluctuate around a long-term upward trend, and are generally within the likely range for random year to year variation about the trend.
3.2 Underlying causes of death
3.2.1 Table 2 shows the number of drug-related deaths categorised by the underlying cause, using groupings of the ICD codes. The majority (370 or 64 per cent in 2008) were coded to "drug abuse" (which is described within the ICD classification as "mental and behavioural disorders due to psychoactive substance use").
3.2.2 As some of the figures can fluctuate markedly from year-to-year, a better indication of the main changes over the years shown in the table should be obtained from a comparison of the averages for the 5-year periods at the start and end. These show that there have been increases in the numbers of deaths for which the underlying cause is "drug abuse" (from an average of 189 per year in 1996-2000 to an average of 277 in 2004-2008), "accidental poisoning" (from an average of 13 to an average of 42), and "undetermined intent" (from an average of 25 to an average of 74). There was little change in the number of deaths caused by intentional self-poisoning (averages of 34 per year in 1996-2000, and 35 in 2004-2008 ).
3.3.1 The GROS database records a wide range of drug combinations (e.g., in 2006, diazepam was mentioned in almost a fifth of the deaths for which heroin or morphine were reported; and heroin, morphine or methadone were mentioned in over half of the deaths for which cocaine was reported). "Unspecified drug(s)" is recorded in only a small proportion of cases (on average, around 3% per year). Table 3 gives information on the frequency of reporting of selected drugs, whether alone or in combination with other substances. The drugs listed in the table are reported in the majority of drug-related deaths (for example, not counting alcohol, at least one of them was reported in 91 per cent of the drug-related deaths in both 2000 and 2008). The table shows a combined figure for ‘heroin/morphine’ because it is believed that, in the overwhelming majority of cases where morphine has been identified in post-mortem toxicological tests, its presence is a result of heroin use.
3.3.2 Since the table records individual mentions of particular drugs, there will be multiple-counting of some deaths (e.g. a death for which both heroin and diazepam were reported would be counted in three columns: under "heroin/morphine", under "benzodiazepines" and under "diazepam"). This means that the table does not give the numbers of deaths that are attributable to each of the drugs mentioned. Where a number of drugs were reported for a particular death, the GROS database does not identify which (if any) of them was thought to be the (main) cause of the death, and has no information about the amounts of each drug that were found, or the possible consequences of taking particular combinations of drugs.
3.3.3 Heroin/morphine was reported in 336 (59 per cent) of the deaths in 2008; methadone was reported in 181 (32 per cent) of the deaths; and benzodiazepines were reported in 364 (63 per cent) of the deaths. Cocaine, ecstasy and amphetamines were reported in 79, 7 and 12 cases respectively. The presence of alcohol was mentioned for 273 of the 574 drug-related deaths in 2008.
3.3.4 The figures for 2008 are not directly comparable with those for earlier years, due to the revision, with effect from 2008, of the questionnaire which collected information about the drugs which were found in the body (see paragraph 2.3). The statistics may also be affected by other differences, between years or between areas, in the reporting of drugs found in the body (see paragraph 2.4). Therefore, apparent changes in the numbers of deaths for which particular drugs were reported must be interpreted with caution, and with the knowledge that there is a clear break in the figures between 2007 and 2008. It is thought that the change in the method of data collection accounts for most (if not all) of the apparent large increases, between 2007 and 2008, in the figures for (e.g.) benzodiazepines, diazepam and alcohol.
3.3.5 Because some of the figures can fluctuate markedly from year to year, the main changes over time are best identified by comparing the averages for 1996-2000 and 2003-2007 (the latter being the final 5-year period before the break in the series). These show that there were marked increases in the numbers of deaths for which there were reports of:
that there was not much change in the numbers of deaths for which there were reports of:
and a marked fall in the number of deaths for which temazepam was reported (from an average of 47 per year in 1996-2000 to an average of 12 in 2003-2007).
3.3.6 However, while comparing 5-year averages should reduce the effect of year-to-year fluctuations, it will not necessarily give the full picture. In this case, it does not reveal some marked changes during the period:
3.4.1 Table 4 shows that males accounted for the vast majority (461, or 80 per cent) of the drug-related deaths in 2008. This was the case throughout the past decade, although the precise balance between the sexes varied from year to year. Comparing the averages for 1996-2000 and 2004-2008, to reduce the effects of year-to-year fluctuations on the figures, the increase in the number of drug-related deaths was greater for males (68 per cent) than for females (53 per cent).
3.4.2 In recent years, of the age-groups shown, the largest number of drug-related deaths has tended to be among 25-34 year olds: using the averages for 2004-2008, 151 out of 428 deaths (35 per cent) were of 25-34 year olds. There were also large numbers in the 35-44 age-group (on average, 134 per year from 2004 to 2008, or 31 per cent). In 2008, there were 211 drug-related deaths of people aged 25-34 (representing 37 per cent of all drug-related deaths) and 174 drug-related deaths of 35-44 year olds (30 per cent). In addition, 92 people aged under 25 died (16 per cent), as did 97 people aged 45 and over (17 per cent). The table shows that the number of deaths in a particular age-group can fluctuate markedly over the years (for example, the number of under 25s who died was 100 in 2002, 48 in 2005, and 94 in 2007). However, some clear trends can be seen. Comparing the averages for 1996-2000 and 2004-2008 (to reduce the effects of year-to-year fluctuations on the figures), there have been large percentage increases in the number of deaths of 35-44 year olds (from an average of 46 per year in 1996-2000 to an average of 134 in 2004-2008) and people aged 45 and over (from an average of 23 to an average of 67); the number of deaths of 25-34 year olds rose less rapidly (from an average of 108 to an average of 151) and there was a fall in the number of people aged under 25 who died (from an average of 83 to an average of 77).
3.4.3 Changes in the ages of drug-related deaths can also be seen from the values of the lower quartile (a quarter of drug-related deaths were of people of this age or under), median (half the deaths were of people of this age or under) and upper quartile (a quarter of the deaths were of people of this age or older), which appear in the table:
The median is used (rather than the average) because it should be affected less by any unusually high (or low) values.
3.4.4 Table 5 shows that, in 2008, 304 (66 per cent) of the male deaths were of known or suspected drug abusers compared to 66 (58 per cent) of the female deaths. Of the 97 deaths aged 45 and over, only 40 (41 per cent) were of people who were known, or suspected, to be drug-dependent. The table also provides a more detailed breakdown of the numbers by age-group for each sex.