Mortality among Australian conscripts of the Vietnam conflict era. II. Causes of death.

In a cohort of Australian national service conscripts, death rates from International Classification of Diseases, Eighth Revision (ICD-8) cause of death classes for 19,205 veterans of the Vietnam conflict were compared with those of 25,677 veterans who served only in Australia. Comprehensive, clinically reviewed cause of death data were collected and coded to a single ICD-8 three-digit cause of death code by the Australian Bureau of Statistics. Over 98% of the deaths among veterans were included in five classes of causes of death. These were neoplasms (14%), diseases of the circulatory system (7%), accidents, poisonings, and violence (external causes) (74%), and diseases of the digestive system and mental disorders (2% each). For the last two classes, chronic abuse of alcohol was a common factor in most deaths among Vietnam veterans. The death rates of Vietnam veterans were statistically significantly higher than those for other veterans for only two classes of causes of death: diseases of the digestive system and external causes. After adjustment for Army corps grouping, this excess was not statistically significant for external causes. There was no statistically significant difference in death rates from neoplasms, nor were deaths from specific neoplasms more frequent among the group that served in Vietnam. While this suggests that service in the Vietnam conflict has not increased death rates from neoplasms among servicemen, the follow-up period, ranging from 9-16 years, is shorter than the latency period for some neoplasms. The study findings provide a measure of support for claims by Australian Vietnam veterans of an increased incidence of stress-related disorders associated with service in the Vietnam conflict.

Mortality among Vietnam veterans compared with non-veterans and the Australian population.

A retrospective cohort study of mortality was conducted to assess whether the military service of young Australian men in Vietnam has influenced their overall death rates, or those from specific causes. The study was of all national servicemen who were conscripted during the conflict and served in the Army for at least 12 months. Of these, 19 205 served in Vietnam (veterans) while 25 677 served only in Australia (non-veterans). These men were traced from the end of their national service (between 1966 and 1973) until the beginning of 1982. For most causes of death, the observed number of deaths of veterans and of non-veterans was less than expected from Australian population death rates, and for no cause was there a statistically significant excess of deaths compared with that of the Australian population. Similarly, when veterans were compared with non-veterans, there was no statistically significant difference in deaths for all causes combined, for diseases of the circulatory system, for deaths in motor vehicle accidents, for suicide and for all external causes after adjustment for the different subsequent death rates of men who had served in different Army corps. All seven deaths from diseases of the digestive system were of veterans. There was no excess of deaths among veterans from cancer or from atypical causes of death in this group of young men. Three-quarters of deaths of both veterans and non-veterans were from external causes, often involving motor vehicle accidents.

The quality of cause of death data for young Australian men.

Accuracy and consistency of death certification and coding practices in Australia were examined in relation to a defined population of 552 young men who died aged 20 to 40 years. For each death a mock death certificate was prepared by a team of physicians using all available clinical, pathological, and coronial data. These certificates, and their International Classification of Diseases (ICD 8) codes derived by an Australian Bureau of Statistics (ABS) nosologist, were compared with the actual death registration papers and their ICD 8 codes. Data for deaths from malignant neoplasms were also compared with results of histopathological review. The mock death certificates were superior to the true death certificates in both completeness of content and accuracy of the recorded cause of death. The major source of discrepancies was unsatisfactory narrative on the original death certificates, the standard of which varied with Australian state and with cause of death. The cause of death coding by ABS was of high standard, but its coding practices generally identify only death certificates where content is inadequate for specific coding. Where the narrative is sufficiently specific to be coded there is no mechanism for checking the accuracy of the cause of death recorded. Suggestions are made for improving the narrative.

Five-year winter chemoprophylaxis for chronic bronchitis.

Seventy-nine patients with chronic bronchitis were randomly allotted to four treatment regimens-placebo throughout the winter months for five years; tetracycline for the first two winters and placebo for the next three; placebo for the first two winters and tetracycline for the next three; and tetracycline for five winters. In addition all groups recevied a five-day course of tetracycline for any acute exacerbation. There was a significant reduction in the number of exacerbations among the more susceptible patients-that is, those who suffered more than one exacerbation each winter. Though the average decline in F.E.V.(1) over the five-year period was less in the treated groups this was not statistically significant. There was no significant difference between the groups in respect of lung volumes, diffusing capacity, and blood gases.