# Exercise: Deaths from volatile substance abuse

This is a section from Martin Bland's text book An Introduction to Medical Statistics, Third Edition. I hope that the topic will be useful in its own right, as well as giving a flavour of the book. Section references are to the book.

## Exercise 16E: Deaths from volatile substance abuse

Anderson et al. (1985) studied mortality associated with volatile substance abuse (VSA), often called glue sniffing. In this study all known deaths associated with VSA from 1971 to 1983 inclusive were collected, using sources including three press cuttings agencies and a six-monthly systematic survey of all coroners. Cases were also notified by the Office of Population Censuses and Surveys for England and Wales and by the Crown Office and procurators fiscal in Scotland.

The table shows the age distribution of these deaths for Great Britain and for Scotland alone, with the corresponding age distributions at the 1981 decennial census.

Volatile substance abuse deaths and population size for Great Britain and for Scotland alone, by age
Age group
(years)
Great Britain Scotland
VSA deaths Population
(thousands)
VSA deaths Population
(thousands)
0-9 0 6,770 0 653
10-14 44 4,271 13 425
15-19 150 4,467 29 447
20-24 45 3,959 9 394
25-29 15 3,616 0 342
30-39 8 7,408 0 659
40-49 2 6,055 0 574
50-59 7 6,242 0 579
60+ 4 10,769 0 962

1. Calculate age specific mortality rates for VSA per year and for the whole period. What is unusual about these age specific mortality rates?
2. Calculate the SMR for VSA deaths for Scotland.
3. Calculate the 95% confidence interval for this SMR.
4. Does the number of deaths in Scotland appear particularly high? Apart from a lot of glue sniffing, are there any other factors which should be considered as possible explanations for this finding?

## Reference

Anderson, H.R., MacNair, R.S., and Ramsey, J.D. (1985) Deaths from abuse of substances: a national epidemiological study. British Medical Journal 290, 304-7.
Solution to this exercise.