3.1.1 On the basis of the definition used for these statistics, there were 455 drug-related deaths in 2007, 34 (8 per cent) more than in 2006 and 231 (103 per cent) more than in 1997. 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 (299 or 66 per cent in 2007) 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 246 in 2003-2007), "accidental poisoning" (from an average of 13 to an average of 34), and "undetermined intent" (from an average of 25 to an average of 61). There was little change in the number of deaths caused by intentional self-poisoning (averages of 34 per year in 1996-2000, and 36 in 2003-2007 ).
3.3.1 A wide range of drug combinations is recorded in the GROS database (for example, in 2006, diazepam was also mentioned in almost a fifth of the deaths involving heroin or morphine; and over half of the deaths involving cocaine also involved heroin, morphine or methadone). Table 3 gives information on the involvement of selected drugs, whether alone or in combination with other substances. The drugs listed in the table are involved in the majority of drug-related deaths (for example, they were involved in over five-sixths of the drug-related deaths in 2006). 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, it will involve multiple-counting of some deaths (e.g. a death involving both heroin and alcohol would be counted in two columns). This means that the table does not give the numbers of deaths that are attributable to each of the drugs mentioned. The GROS database has no information about which (if any) of the drugs mentioned were thought to have caused each death, the amounts of the different drugs that were found, or the possible consequences of taking particular combinations of drugs.
3.3.3 Heroin/morphine was involved in 289 (64 per cent) of the deaths in 2007; methadone was involved in 114 (25 per cent) of the deaths; and diazepam was involved in 79 (17 per cent) of the deaths. Cocaine and ecstasy were involved in 47 and 11 cases respectively. The presence of alcohol was mentioned for 157 of the 455 drug-related deaths in 2007.
3.3.4 As some of the figures can fluctuate markedly from year-to-year, the main changes over the years shown in the table should be found by comparing the averages for the 5-year periods at the start and end. These show that there have been marked increases in the numbers of deaths involving:
that there has been not much change in the numbers of deaths involving:
and a marked fall in the number of deaths involving temazepam (from an average of 47 per year in 1996-2000 to an average of 12 in 2003-2007).
3.3.5 However, while comparing the 5-year averages at the start and end of the period should reduce the effect of year-to-year fluctuations, it may not show all the main trends. 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 (393, or 86 per cent) of the drug-related deaths in 2007. 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 2003-2007, 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 (48 per cent) than for females (34 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 2003-3007, 134 out of 377 deaths (36 per cent) were of 25-34 year olds. However, in 2007, the numbers of 25-34 and 35-44 year olds who died were the same: 149 in each age-group (in each case, representing 33 per cent of the total of 455 deaths). In addition, 94 people aged under 25 died (21 per cent), as did 63 people aged 45 and over (14 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 2003-2007 (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 115 in 2003-2007) and people aged 45 and over (from an average of 23 to an average of 54); the number of deaths of 25-34 year olds rose less rapidly (from an average of 108 to an average of 134) and there was a fall in the number of people aged under 25 who died (from an average of 83 to an average of 74).
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 2007, 269 (68 per cent) of the male deaths were of known or suspected drug abusers compared to 30 (48 per cent) of the female deaths. Of the 63 cases aged 45 and over, only 27 (43 per cent) 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.