1301.0 - Year Book Australia, 2002  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 25/01/2002   
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Contents >> Health >> Drug-related deaths

DRUG-RELATED DEATHS

Drug abuse is often considered to be an indicator of general social dysfunction, a particularly serious consequence of which is the premature deaths of drug users. The number and nature of drug-related deaths in a community are the result of numerous social forces, including the prevalence of illicit drug use, the types of drugs being used, and the response of government and society to the issue of drug abuse. This article focuses solely on deaths occurring between 1979 and 1999 which were caused by the use of illegal drugs and the misuse of legal drugs other than tobacco and alcohol.

In 1998, 3.3 million Australians, or 23% of people aged 14 years and over, reported that they had used illicit drugs in the previous 12 months (AIHW 2000b). Cannabis was the most prevalent drug used (by 18% of people in this age group), with the more potentially lethal illicit drugs being used by much smaller proportions of people. Amphetamines were used by 4% of people aged 14 years and over, ecstasy by 2% and heroin by less than 1%.


Drug-related deaths are those caused directly by drug abuse, including deaths from organ damage caused by drugs. They include deaths from illegal drugs as well as the misuse of legal drugs.

Excluded from the article are: deaths directly attributable to alcohol and tobacco use; deaths from poisoning or exposure to volatile organic compounds (such as petrol); and murder where drugs were the weapon. Also excluded are deaths such as some road traffic accidents or AIDS deaths where drug use partially contributed to the death.

Deaths from 1979 to 1998 were classified according to the International Classification of Disease Ninth Edition (ICD–9), while deaths in 1999 were classified according to the Tenth Edition (ICD–10). The drug-related deaths from these different classifications have been matched to facilitate comparisons over time.

In this article, drug-related deaths include the following categories from the ICD–10:
  • suicide by drugs (X60–X64);
  • accidental drug-related deaths which includes two components: accidental poisoning by drugs (x40–X44) and mental and behavioural disorders due to drug use (F11–F16 , F19 & F55); and
  • drug deaths where the intent of the poisoning was undetermined (Y10–Y14).

Trends in drug-related deaths
In 1999, there were 1,737 deaths where the underlying cause was identified as drug-related, representing 1.4% of all deaths in that year. The number of drug-related deaths in 1999 was almost two and a half times the number in 1979 (734). Over the 1979-1999 period, the standardised drug-related death rate increased by 79%, from 5 to 9 deaths per 100,000 population.

The overall increase in drug-related deaths over this 20 year period was driven primarily by increases in drug-related deaths of males. In 1979, males and females had similar standardised drug-related death rates (around five deaths per 100,000 population). By 1999, the rate for males had grown to almost 14 deaths per 100,000 while the rate for females was still around 5 per 100,000 (graph 9.15). Consequently, males accounted for 72% of drug-related deaths in 1999 compared with 48% in 1979.




Accidental drug-related deaths

Drug-related deaths are usually the result of an unintentional overdose or the effects of prolonged misuse of drugs. The rates of accidental deaths due to drugs increased more rapidly between 1979 and 1999 than those for all drug-related deaths, a fourfold increase from 2 to 8 deaths per 100,000 population. Of the total drug-related deaths in 1999, 81% were accidental, 16% were suicides and 3% were of undetermined intention. In contrast, accidental drug-related deaths comprised just 35% of all drug-related deaths in 1979.

The accidental drug-related death rate for males increased sixfold over the period to 11 deaths per 100,000 population, with 80% of this increase occurring since 1989. In comparison, the death rate for females increased from 2 to 4 deaths per 100,000 between 1979 and 1999 (graph 9.16). Consequently, despite having similar death rates in 1979, by 1999 the rate for males was almost three times that for females.

Increases in the use and availability of heroin (an opiate) have been a focus of public debate over the 1990s. Opiates were the cause of 31% of accidental drug-related deaths in 1979. By 1999, this had increased to 63%.




Suicides by drugs

In contrast to accidental drug-related deaths, suicides by drugs decreased over the 1979–1999 period. Furthermore, the death rates from suicides by drugs were more equally distributed between males and females. Rates for both males and females declined from 3 per 100,000 in 1979 to around half that in 1999 (graph 9.17).




The suicide rate for non-drug-related methods for males increased from 15 to 20 deaths per 100,000 population over the 1979-1999 period, while the corresponding rate for females increased from 3 to 4 deaths per 100,000 population. Consequently, the proportion of all suicides from drugs has halved; from 16% to 8% of male suicides, and from 49% to 24% of female suicides.


Demographic characteristics

The tendency of people to die from drug-related causes varies across the population, according to people’s ages, marital status and place of residence. In addition, the demographic characteristics of people who died accidentally from drug-related causes differed substantially from those of people who suicided using drugs.

In 1999 rates of accidental drug-related deaths were highest among young adults, peaking among 25-29 year olds at 20 deaths per 100,000 population, gradually falling with age before stabilising at around 2 deaths per 100,000 for people aged 55 years and over (graph 9.18).

Over the last two decades there has been a steady increase in the age at which people die from accidental drug-related causes, due to the large increase in the death rate from this cause of men aged in their 30s and 40s. This may reflect the ageing of the population of illicit drug users over the period.

Accidental drug-related death rates were highest for people who had never married (25 deaths per 100,000) and for those who were divorced (16 per 100,000 population). In contrast, the death rate for people who were married was 2 deaths per 100,000 in 1999. The comparatively low rate for married people suggests they may be less likely to use drugs, especially more lethal drugs such as heroin.

Accidental drug-related death rates in capital cities were around 50% higher than those in the rest of the country, with particularly high rates in Melbourne and Sydney. The highest rates tended to be in the inner suburbs of capital cities.
The demographic characteristics of people who committed suicide using drugs were very different to those of people who died accidentally from drug-related causes. They also had quite different characteristics to those who suicided using other methods.

In 1999, there were 278 suicides by drugs, accounting for 11% of all suicides in that year. Drugs were used in 25% of the suicides of females, making it the second most common method after hanging and strangulation (33%). Drugs were used in 8% of the suicides of males, making it the fourth most common method after hanging and strangulation (43%), exposure to gases (mostly carbon monoxide from motor vehicle exhaust) (24%), and firearms (13%).

Rates of suicide by drugs were relatively constant among all ages from 25 years on, with age-specific death rates around 2 deaths per 100,000 population (graph 9.18). In contrast, the rate for all suicides peaked among 20 to 34 year olds and declined with increasing age. However, as a proportion of all suicides, drug suicides increased with age, with 13% of suicides of people aged 50 years and over from drugs, compared with 3% for those aged less than 20 years.




As with accidental drug-related deaths, unmarried people were more likely to die from drug-related suicides than married people. In 1999, the drug-related suicide rates for people who had never married, or who were divorced or widowed were five, four and eight deaths per 100,000 population respectively, compared with one death per 100,000 of people who were married (table 9.19).

In 1999, capital cities had a standardised death rate for suicides by drugs of 1.5 deaths per 100,000 population, compared with 1.2 outside capital cities. However, non-drug methods of suicide were more common outside the capital cities where the standardised rate was 13 deaths per 100,000 population (compared with 11 in the capitals).

9.19 DRUG-RELATED DEATHS, Selected Characteristics - 1999

Accidental drug-related deaths
Suicide by drugs
All suicides
Proportion of all
suicides due to drugs
rate per 100,000
rate per 100,000
rate per 100,000
%

Age specific rates
0–19 years
1.4
0.1
2.7
3
20–34 years
17.8
2
20.7
10
35–49 years
10.8
2.2
17.7
12
50 years and over
2.3
1.8
13.8
13
Sex(a)
Males
11.4
1.6
21.2
8
Females
3.9
1.2
5.1
25
Registered marital status(a)
Never Married
24.8
5.1
38
14
Married
2.2
0.9
10
9
Widowed
9.9
7.7
29.6
26
Divorced
15.7
4.4
23.2
19
Part of State(a)
Capital city
8.4
1.5
12.1
12
Balance of State
5.5
1.2
14.2
9

deaths
deaths
deaths
%
Total
1,403
278
2,492
11

(a) Standardised.

Source: Data available on request, ABS Causes of Death Collection.


Types of drugs

Because of the pharmacological interactions between different drugs, having a mixture of drugs is more likely to result in adverse health effects including death, than use of a single type of drug. For example, alcohol increases the effects of some drugs, and was present in 14% of accidental drug-related deaths as a contributing factor rather than as the drug that ultimately caused the death.

In 1999, opiates were involved in 63% of accidental drug-related deaths, while benzodiazepines were involved in 27% (table 9.20). Opiates were involved in the highest proportions of accidental drug-related deaths of both males and females (67% and 50% respectively). However, the accidental deaths of females were more likely to involve benzodiazepines (35%) and antidepressants (28%) than those of males (25% and 10% respectively).

The drugs used most commonly in suicides were benzodiazepines, antidepressants and opiates, with each involved in a third of all suicides by drugs. Antidepressants were more likely to be used by females who suicided than by males (46% and 23% respectively), as were drugs such as paracetamol (18% and 8% respectively). Alcohol was also used in combination with other drugs in 19% of suicides by drugs, although it was not the underlying cause of the death.

9.20 TYPES OF DRUGS(a) CONTRIBUTING TO DRUG-RELATED DEATHS - 1999

Suicide by drugs
Accidental drug-deaths
ICD–10 Code
Example/ common name
Males
Females
Males
Females

Drug poisoning
%
%
%
%
4–Aminophenol derivatives
T391
Paracetamol
8
18
3
10
Opiates
T400-402
Heroin/morphine
34
32
67
50
Methadone
T403
Methadone
6
2
8
10
Other Narcotics & Hallucinogens
T404-409
Pethedine
10
8
15
18
Benzodiazepines
T424
Valium/ tranquilisers
34
33
25
35
Antidepressants
T430-432
Antidepressants
23
46
10
28
Psychostimulants
T 436
Methyl-amphetamines
-
-
5
5
Alcohol(b)
T51
Alcohol
22
14
16
10
Total(c)
100
100
96
96
Long term organ damage
-
-
5
2
Total(c)
100
100
100
100

no.
no.
no.
no.
Deaths
158
120
1,043
357

(a) Drugs mentioned on the medical certificate. These drugs may be the underlying cause, or may be a contributing part of a mixture of drugs which lead to the death.
(b) Alcohol is not included in the scope of accidental poisoning in this article. Therefore alcohol is not the underlying cause of death, but taken in conjunction with other drugs, has led to these deaths.
(c) Death may be caused by more than one drug and therefore components do not add to total.

Source: ABS data available on request, ABS Causes of Death Collection.