Download Frequently Asked Questions - Department of Veterans` Affairs

Frequently Asked Questions
Vietnam Veterans Mortality and Cancer Incidence Studies
1) I am a Vietnam veteran. Why was I not contacted for this study?
The studies investigated the mortality and cancer incidence of Vietnam veterans from
all three service branches. The information for this type of study was obtained by
matching the names and dates of birth of veterans from the Vietnam Veterans
Nominal Roll to national databases such as the National Death Index and the Cancer
Registries. This data matching gives information on date and cause of death and
cancers diagnosed. The mortality rates and cancer incidence can then be calculated
from this information. There was no need to personally contact individuals to obtain
the data needed to undertake these studies.
2) What is the Healthy Worker Effect?
The Healthy Worker Effect is a phenomenon observed in occupational health studies
in which those who are employed have a lower mortality than the general population
which includes those employed and those who are too ill or disabled to work. Many
factors can modify this extent of this effect, such as subsequent employment, lifestyle,
age and length of follow-up. The Healthy Worker Effect does not affect all causes of
death equally. Generally, the effect of lower mortality is largest for cardiovascular
diseases, diabetes and respiratory disease whereas the effect is small for cancer
mortality.
The National Servicemen study is able to take into account the Healthy Worker Effect
by comparing the mortality and cancer incidence of National Service personnel who
served in Vietnam to those who served in Australia. It compares two groups who
were of similar health and fitness at the time of enlistment and who differed by
service in Vietnam.
3) Why are the number of deaths for some cancers more than the number of
cancers diagnosed (incidence)?
The study period for the mortality study was from 1963 to 2001 whereas the study
period for the cancer incidence study was from 1982 to 2000. The difference in study
periods is because national data for cancer incidence is available from 1982 only
whereas mortality data is available for a much longer time period.
4) Who did the Study?
The study was done by the Department of Veterans’ Affairs and the Australian
Institute of Health and Welfare. The scientific aspects of the study were overseen by
a Scientific Advisory Committee made up of eminent academics in the fields of
epidemiology, cancer research, toxicology and biostatistics and chaired by Professor
Peter Smith, Dean of the Faculty of Medicine, University of New South Wales.
5) Were Vietnam veteran representatives involved during the study?
A Consultative Forum made up of representatives of key ex-service organisations, the
Vietnam Veterans Association, the Vietnam Veterans Federation, the Naval
Association, the RSL and the Australian Veteran and Defense Service Council, have
been involved in the study from the beginning and have met regularly to discuss its
progress and findings.