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MORTALITY STUDY 2003

Australian Veterans of the Korean War

Executive summary

Identifying deaths amongst veterans
Number of veteran deaths studied
Findings
Cancer mortality
Effect of Nature of Service
Strengths and weaknesses of the study
Conclusion
Recommendations

This is a study of the mortality patterns of Australian Korean War veterans following the Korean War. It was prompted by concerns from the Korean War veteran community that their death rates were higher than the Australian male population, and that this increase was due to their service in Korea.

It is the first mortality study of all Australian military personnel, Royal Australian Navy, Australian Army, Royal Australian Air Force and included a small number of members of approved philanthropic organisations - Australian Red Cross, Salvation Army and Young Men's Christian Association - who served in Korea. It covers deaths of veterans in the period 27 June 1950 to 31 December 2000 following completion of Korean service.

The aims of the Korean War Veterans Mortality Study were to:

develop a nominal roll of all Australian veterans of the Korean War,
develop a geographic profile of all living Australian veterans of the Korean War,
determine mortality rates of Australian veterans of the Korean War, and
compare the mortality rates of male Australian veterans of the Korean War with those of Australian males.

A protocol for this study was completed in September 1999. It defined the study aims, methods of data collection and analysis, limitations of the study, reporting, and privacy and confidentiality considerations. The absence of quantitative data on occupational and environmental exposures was acknowledged.

Ethical approval for the study was obtained from the Department of Veterans' Affairs (DVA) Ethics Committee and the Australian Institute of Health and Welfare (AIHW) Ethics Committee.

The study was conducted by DVA while the AIHW ascertained the causes of death and compared the death rates of Korean War veterans with the Australian population. An independent Scientific Advisory Committee was established to oversight the scientific aspects of the study and representatives of ex-Service organisations formed a Consultative Committee to represent the interests of Korean War veterans.

Table 1 shows the total numbers of male and female Korean War veterans on the Nominal Roll, categorised by the first organisation in which they served.

Table 1: Number of veterans on the nominal roll
	Males	Females	Total
Navy	5,769	0	5,769
Army	10,814	34	10,848
Air Force	1,204	21	1,225
Philanthropic organisations^a	16	3	19
Civilians^b	10	0	10
Total	17,813	58	17,871
^a Includes personnel from the Australian Red Cross, Salvation Army and Young Men's Christian Association. ^b Includes war correspondents and civilian canteen staff aboard HMAS Sydney

Because only 58 females served in the Korean War, it was not feasible to conduct a scientifically reliable cohort study of mortality rates amongst female veterans. Accordingly, mortality rates were derived for male veterans only.

Identifying deaths amongst veterans

After the nominal roll had been compiled, the names of male veterans were matched with a number of registers to determine whether the veterans had died since the end of their service in Korea or were still alive on 31 December 2000. The sources of data on vital status were: Department of Defence records; DVA records; the National Death Index; Electoral Commission rolls; the Health Insurance Commission Medicare database; and, for pre-1980 deaths, death registers maintained by New South Wales, Victoria, Queensland, Western Australia, South Australia, Tasmania and Australian Capital Territory Registries of Births, Deaths and Marriages. The New Zealand Registry of Births, Deaths and Marriages also provided details of Australian male veterans who had died in that country. Just over 81% of all veterans were identified on DVA databases, and this became the major source of information on the vital status of veterans.

A total of 17,813 males served in the Korean War, and 339 veterans were killed in action and 10 died of injury or disease in Korea during the cease-fire period between 28 July 1953 and 19 April 1956. These 349 deaths were excluded from the study. The study population thus consisted of the remaining 17,464 male veterans who returned to Australia following their Korean War service. Table 2 shows the number and percentage of male veterans determined to be alive or dead in the study as at 31 December 2000. After a search of death records covering nearly 50 years, the vital status of 5.1% remains unknown. This percentage is very low for a study of this type. The distribution of unknowns varied between the Services and vital status was most difficult to determine in the Army. There is evidence that many veterans of unknown vital status may have emigrated from Australia since the end of the Korean War, but the numbers were not able to be quantified. Other veterans may not have been found due to changed names.

Table 2: Summary results of nominal roll matching
Group	Alive	Dead	Unknown	Total
Navy	3,256	2,271	239	5,766
Army	4,976	4,929	626	10,531
Air Force	638	508	21	1,167
Total	8,870	7,708	886	17,464
	Per cent
Navy	56.5	39.4	4.1	100
Army	47.3	46.8	5.9	100
Air Force	54.7	43.5	1.8	100
Total	50.8	44.1	5.1	100

The place of residence of Korean War veterans who were alive on 31 December 1999 (the initial study end-date) was determined from the postcode recorded on the relevant State or Territory electoral roll provided by the Australian Electoral Commission. Surviving male Korean War veterans live predominantly on the coast of the eastern states. Furthermore, approximately 60% of all surviving veterans are urban metropolitan dwellers - living in the State and Territory capitals.

The statistical analysis of the Korean War veteran cohort employed standard statistical methods for cohort studies. The following information was determined in order to conduct the analysis:

the population at risk in the veteran cohort by age and calendar period, duration of service in Korea, and branch of Service;
the number and cause of deaths in the veteran cohort by age, calendar period, duration of service in Korea, and branch of Service; and
the age-specific mortality rates by calendar period and cause in the comparison population, in this case Australian males with a comparable age profile.

The results presented are obtained from analysis of deaths of veterans whose vital status has been determined. These results assume that veterans of unknown status had the same mortality rate as the veterans whose vital status is known which may or may not be true. The 886 veterans in the unknown category are referred to as the 'veterans whose vital status is unknown' for the purposes of this study. The effect on the results of excluding this group was assessed in an additional analysis. This additional analysis assumes that all veterans of unknown vital status are alive (an unlikely situation). The results from this analysis can then be compared with the previous results to assess their validity. Both sets of results are presented in the body of the report. The most likely results, that is, where it is assumed veterans of unknown status had the same mortality rate as the veterans whose vital status is known, are presented as Scenario 1. The additional analysis that assumes all veterans of unknown status are alive is presented as Scenario 2 and is an under-estimation of risk. The results from Scenario 2 reveal that the conclusions reached in Scenario 1 are robust. For readability, results from Scenario 1 only are presented in the Executive Summary.

Number of veteran deaths studied

Australian male mortality rates, against which the Korean War veterans' deaths are compared, only refer to deaths within Australia. Accordingly, veterans who died in the Vietnam War or elsewhere overseas during the period of the study have been excluded, as were 79 deceased veterans with an unknown date of death and two deceased veterans with unknown dates of birth.

Following these exclusions, a total of 7,514 veteran deaths were included in the study. Of these deaths, a cause of death could not be determined for 262 (3.5%). For these deaths, a cause of death was assigned in line with the mortality pattern of known causes existing amongst the other veterans who died in the same time period.

Findings

In this section, all references to elevation or lowering of mortality rates are statistically significant compared to the Australian male population.

During the development of the protocol for the study, causes of death of a priori interest were identified from the literature and consultation with veterans. Mortality from 13 causes of death of a priori interest were elevated (section 6.2 refers). They included mortality from all causes, chronic obstructive pulmonary disease, ischaemic heart disease, stroke, alcoholic liver disease and external causes, such as suicide and motor vehicle accidents.

Among the cancers of interest, mortality rates for cancer of the oesophagus, gastrointestinal and colo-rectal cancers, head and neck, lung, genito-urinary and prostate cancers were elevated. Mortality rates from two a priori diseases (tuberculosis and peptic ulcer disease) and four cancers (liver and gallbladder, mesothelioma, melanoma and leukaemia) did not differ from that of Australian males.

None of the a priori diseases showed a lower mortality rate.

As for the Australian male population, the most common causes of death were from diseases of the circulatory system, cancer, external causes such as suicide and motor vehicle accidents, and diseases of the respiratory system.

Overall, Korean War veterans experienced a 21% higher mortality rate than an equivalent Australian male population.

Elevated mortality rates for specific causes of death were found for a number of conditions:

the death rate from diseases of the circulatory system was elevated by 13%, with ischaemic heart disease elevated by 10% and stroke by 17%.
the death rate from cancer was elevated by 31%;
the death rate from all external causes (homicides, accidents and suicides) was elevated by 37%, with suicides elevated by 31%;
the death rate from respiratory diseases was elevated by 32%. Chronic obstructive pulmonary disease information has been available since 1979 and was elevated by 49%. Respiratory diseases remained elevated by 45% after exclusion of chronic obstructive pulmonary disease;
the death rate from all digestive diseases was elevated by 35%, with deaths from diseases of the liver, gallbladder and bile ducts elevated by 33% and deaths from alcoholic liver disease elevated by 36%.

Korean War veterans had lower mortality rates for diseases of the skin (reduced by 74%) and congenital malformations (reduced by 64%), with one and three deaths recorded respectively.

Mortality by Service branch

Of the three Services, Army veterans experienced the highest level of mortality followed by Navy, then Air Force. Air Force veterans showed a statistically significantly lower mortality rate than the Australian male population.

The most common causes of death in each Service were the same as for all Korean War veterans overall and the Australian male population, and were from diseases of the circulatory system, neoplasms, external causes such as suicide and motor vehicle accidents, and diseases of the respiratory system.

Navy
Navy veterans experienced an 11% overall increased mortality rate with an increased mortality from:

circulatory diseases (elevated by 9%), including stroke (21% increase);
neoplasms (elevated by 22%); and
chronic obstructive pulmonary disease (elevated by 30%).

Navy veterans had a lower mortality for four of the 27 causes of death analysed:

the death rate from infectious diseases was 44% lower;
the death rate from tuberculosis was 73% lower;
the death rate from genito-urinary diseases was 39% lower; and
the death rate from motor vehicle accidents was 27% lower.

Army
Compared to the Australian male population, Army veterans had a 31% increased mortality rate for all cause mortality and for 13 other causes of death. Specifically:

the death rate from all circulatory diseases was elevated by 20% with rates from ischaemic heart disease and stoke being elevated by 18% and 22% respectively;
the death rate from neoplasms was elevated by 41%;
the death rate from external causes was elevated by 58%, with suicides elevated by 53%;
the death rate from all respiratory diseases was elevated by 48%. Chronic obstructive pulmonary disease information has been available since 1979 and was elevated by 69%, and respiratory diseases excluding chronic obstructive pulmonary disease elevated by 57%; and
the death rate from all digestive diseases was elevated by 57%, including rates from diseases of the liver, gallbladder and bile ducts elevated by 51%, peptic ulcer disease elevated by 90%, and alcoholic liver disease elevated by 47%.

Army veterans showed a lower mortality rate for one cause of death, that being deaths from congenital malformations which was 79% lower than for Australian males.

Air Force
Air Force veterans demonstrated an 11% lower mortality rate for all causes of death. Lower mortality rates were demonstrated for three causes of death, specifically:

the death rate from all circulatory diseases was 18% lower, including deaths from ischaemic heart disease which was 16% lower; and
the death rate from alcoholic liver disease which was 65% lower.

Cancer mortality

All Services

Mortality from specific cancers was investigated by individual primary site. For all male Korean War veterans, the most frequently occurring cancer deaths are from lung, gastrointestinal and genito-urinary cancers. The overall death rate from cancers was elevated by 31% compared to the Australian male population. Specifically:

the death rate from lung cancer was elevated by 47%;
the death rates from gastrointestinal cancer and colo-rectal cancer were increased by 18%;
the death rate from genito-urinary cancer was increased by 24%;
the death rate from cancers of the head and neck was elevated by 96%;
the death rate from cancer of the oesophagus was elevated by 59%;
the death rate from cancer of the larynx was elevated by 95%; and
the death rate from cancer of unknown primary site was elevated by 51%.

Cancer mortality by Service branch

The most common deaths from cancer in the Navy and Army were similar to those of all Korean War veterans, that is from lung, gastrointestinal and genito-urinary cancers. However, in the Air Force, genito-urinary cancers were more common than gastrointestinal cancers.

Navy
A significantly elevated mortality rate of 22% was found for all neoplasms. Lung cancer was elevated by 27%, genito-urinary cancers by 34% and cancer of the head and neck was elevated by 109%. Death from lymphoid leukaemia among Navy personnel was 60% lower than the Australian male population.

Army
An elevation in mortality rate from all neoplasms of 41% was found in the Army. Specifically:

lung cancer was elevated by 69%;
gastrointestinal cancer was elevated by 24% with colo-rectal cancer increased by 22%;
cancer of the head and neck was elevated by 90%;
cancer of the oesophagus was elevated by 82%;
cancer of the liver and gallbladder was elevated by 67%;
cancer of the larynx was elevated by 144%; and
cancer of unknown primary site was elevated by 77%.

Air Force
Overall cancer mortality was not elevated, and only prostate cancer was statistically significantly elevated among Air Force veterans by 71%. Two cancer categories, liver and gallbladder cancer, and stomach cancer, showed a lower mortality rate among Air Force veterans of 75% and 59% respectively.

Smoking-related cancers

Many cancers for which there was elevated mortality among the Korean War veterans are cancers associated with smoking. Modelling indicates that very high rates of smoking would be required to account for the increases observed and might not account for all the cancer elevation. However in the absence of information about the percentage of veterans who smoked and the numbers of cigarettes smoked per day, it is not possible to determine precisely how much of the excess mortality could be attributed to smoking. Therefore this limits the ability to assess the extent to which other possible causes have contributed to the deaths apart from tobacco consumption.

Effect of Nature of Service

The nature of service in Korea varied considerably between the Navy, Army and Air Force. Navy personnel spent an average of 249 days in Korean waters with 85% completing one tour only. Army personnel averaged 305 days in Korea with 77% completing one tour only. In contrast, only 57% of Air Force personnel completed one tour only, with an average duration of service of 145 days. The large number of visits conducted by Air Force personnel reflects both the arrangements for aircraft maintenance, which were split between Korea and Japan, and the operational transport role, including aeromedical evacuation.

Almost 9% of Korean War veterans participated in the Vietnam War and the DVA client database indicates that at least 30% of Korean War veterans participated in World War II. These factors need to be taken into consideration when interpreting the results.

Given the absence of quantitative data on exposure to occupational and environmental hazards, the effect of duration of service and the period of service in Korea were investigated for Navy and Army veterans. (The number of Air Force veterans was too small for this analysis.) Mortality by duration of service in Korea for Navy and Army veterans did not show any clear pattern between the different duration categories or within each Service branch.

However, investigating mortality by period of service among Army veterans reveals that those who completed their Korean service prior to 1952 (which marked the end of the offensive / counter-offensive phase of the conflict), had a significantly lower mortality rate from suicide compared to the Australian male community. Those who served in Korea after 1952 had a higher mortality rate from suicide compared to Australian males. Apart from this unexpected and possibly chance post hoc finding, there was no other apparent trend from the effect of period of Korean service on mortality.

Strengths and weaknesses of the study

The study has various strengths, and, given the constraints of the study design, unavoidable weaknesses that affect its interpretation.

The strengths of this study include:

identification of the total veteran population was close to complete;
follow-up or tracing was from the end of service until 31 December 2000 - the length of time that elapsed since service ranged from approximately 44 to 50 years;
vital status was established for 94.9% of veterans in the study; and
the study was conducted in a country with an advanced medical system ensuring the majority of causes of death are accurately classified.

The weaknesses of this study include:

there was an under-ascertainment of deaths. About 5.1% of the Korean War veterans could not be located. It is expected that some of these have died prior to the establishment of the National Death Index. This may have lead to an under-estimation of the effects of Korean War service;
there was a lack of measurement of exposure to risk factors that might contribute to the observed associations, such as cigarette smoking, alcohol intake, hepatitis B virus infection, endemic parasites and bacteria, pesticides, solvents, chemical exposures and environmental exposures in Korea; and
the exposure measures available were duration and period of service in Korea. These could not reflect occupational variations or the variation in exposure to Korean War service within and between the Royal Australian Navy, Australian Army and Royal Australian Air Force.

Conclusion

This study has demonstrated that participation in the Korean War is associated with an overall increase in mortality of 21% and an increase in cancer mortality of 31%. Korean War veterans have an elevation in mortality from 12 of the a priori diseases of interest. Mortality was highest in Army veterans and lowest in Air Force veterans.

Because of the limitation in measurement of factors known to affect mortality, their contribution to the increase in mortality could not be determined. Some of the diseases with higher mortality rates have been linked with cigarette smoking. Although Korean War veterans have a higher mortality for several causes of death that have been identified, there is no way of determining whether this resulted from some exposure in Korea or whether it was the result of lifestyle changes arising as a consequence of Korean War service or a combination of both.

Recommendations

1. The Korean War has been referred to as ' The Forgotten War'. This study has demonstrated that participation in the Korean War is associated with an overall increase in mortality of 21% and an increase in cancer mortality of 31%. About 50% of all Korean War veterans are still alive. In light of the demonstrated increase in mortality consideration should be given to targeted health interventions for the surviving Korean War veterans.

2. This mortality study should not be considered in isolation, but with the companion studies that are being undertaken simultaneously. Thus, this study and the companion cancer incidence study should be referred to the Scientific Advisory Committee oversighting the health study of surviving Korean War veterans, as these studies may indicate additional areas to address in the health survey.

3. There is anecdotal evidence that Australian veterans of the Korean War smoked more than the comparable Australian population. A health survey of surviving veterans of the Korean War is about to commence. It is recommended that the level of cigarette consumption in the survivors be assessed and that the current survey of veterans of the Korean War include questions on current smoking. This may allow programs of smoking cessation to be more effective and to be better targeted within the Korean War veterans.

4. Similarly, the increase in mortality from alcoholic liver disease indicates that the level of alcohol consumption be assessed in the health survey of survivors. This may allow programs aimed at reducing alcohol intake to be better targeted within the surviving Korean War veterans.

5. The information from the current study, including the date when each veteran was last known to be alive or dead, should be stored safely together with the nominal roll. Updated vital status data should be stored separately and this information made available for the general health survey of surviving Korean War veterans.

6. In this study there was considerable difficulty in locating some veterans. Some of this difficulty was due to errors in recording client data in the DVA database and matching against Defence records. DVA should liaise with Defence to ascertain methods of improving matching against Defence personnel records. This should be of longer term benefit in conducting studies of cohorts of veteran populations and may lead to improvement in quality control systems on data entry.