The Australian Korean War veterans’ Health Study was designed to complement the recently completed Australian Korean War veterans’ Mortality, [19] and Cancer Incidence, [20] Studies. Together, these three studies constitute the first major study program of health in this Australian veteran population. The Health Study was a survey of the entire population of Australian Korean War veterans known to be alive and residing in Australia, and a comparison survey of a sample of similarly aged Australian men registered on the Australian Electoral Roll and reportedly residing in Australia at the time of the Korean War.
The Korean War veterans’ Health Study aimed to compare the two groups on measures of self-rated quality of life and life satisfaction, indicators of depression, alcohol misuse and anxiety including posttraumatic stress disorder (PTSD), self-rated physical health, reported medical conditions and hospitalisations. The study also investigated whether specific service-related characteristics of the Korean War deployment were associated with current health.
Commissioned and funded by the Australian Government Department of Veterans’ Affairs (DVA), and conducted by staff at Monash University’s Department of Epidemiology and Preventive Medicine, the Australian Korean War veterans’ Health Study commenced in early 2004 with recruitment closing in August of that year.
Recruitment, investigation of possible participation bias, and effects of proxy respondents
The study achieved an excellent participation rate within the Korean War veteran group, with more than 81% of 7,525 eligible Korean War veterans participating by returning their completed participant questionnaires. This high recruitment rate reflects the enthusiasm in the Korean War veteran community for this long-awaited health study, more than fifty years after the cease-fire.
The participation rate within the population sample was satisfactory, with 64% of 2,964 subjects returning completed questionnaires. 1,505 (80%) of the participating population sample subjects were subsequently assessed as being Australian born or having resided in Australia at the time of the Korean War, and therefore eligible for inclusion in the comparison group against which the results of the Korean War veterans were compared.
Participants in both study groups provided very complete data with very few responses missing from their questionnaires. Most of the questionnaire instruments could be fully scored for between 95% and 99% of all participants.
In both study groups the participation rates, and questionnaire data quality, represented substantial improvements over those achieved in the 2002 pilot study. These improvements can be partly attributed to modifications which were made to the main study design as a direct result of careful appraisal of the pilot study results.
Participation bias can occur if the health status of non-participants differs markedly, on average, to that of participants. This is less likely to have occurred in the Korean War veteran group where the participation rate was high, than in the population sample where the rate was lower. Several methods were used in the study to assess possible participation bias in both groups. Comparison of participants with non-participants on known demographic variables suggested that participants were very representative of the larger populations from which they were drawn, with participation rates varying little across known group characteristics including Service branch and rank during Korea, and current State or Territory of residence.
It was noted that non-participation was highest amongst the oldest subjects, and that refusers were more likely to report poorer general health and lower life satisfaction than participants. These differences are likely to have resulted in some over-estimation of the true health status of both study populations, compared with that which would have been observed if full participation had been achieved. However, the pattern of non-participation by older, and less well, subjects was observed in both study groups and, therefore, it was unlikely to notably effect the magnitude or direction of the differences in health outcomes between study groups which were observed in the study.
To maximise participation by the oldest and least well subjects, and by those unable to complete a written questionnaire for any other reason, subjects were invited to seek the assistance of a proxy, such as a relative, friend or carer, to complete the questionnaire. Previous studies comparing self-reported versus proxy ratings of health have demonstrated reasonable agreement between subjects and their proxies on reports of quality of life, [161] medical histories and medication use, [162, 163] and smoking status, [164] but also a tendency for proxies to over-estimate impairment and under-estimate quality of life, [165] and for agreement to decrease as level of impairment increases. [161] Assessment of proxy respondents in our study showed that only a small proportion of questionnaires were completed by proxy in both study groups, and that most proxies transcribed answers provided by the participants rather than estimating their own answers on behalf of the participants. In fact only 70 Korean War veteran questionnaires (1%) and 44 population sample questionnaires (2%) were completed by proxies who reported writing their own answers on behalf of the invited participants. With such small numbers of true proxy responses it was considered unlikely that misclassification of participant health, resulting from proxies erroneously estimating questionnaire responses, would notably impact upon the results of this study.
Overview of the participating Korean War veterans
At the time of completing their questionnaires, the 6,122 participating male Korean War veterans ranged in age from 66 to just under 100 years old. They had averaged just 23 years of age at the time of their deployment to Korea. Approximately 38% had served with the Royal Australian Navy (Navy), 55% with the Australian Army (Army) and 8% with the Royal Australian Air Force (Air Force). Most (78%) undertook one tour of duty during the Korean War, and the average duration of a tour was 218 days for the Navy, 245 days for the Army and 108 days for the Air Force. The majority of veterans (74%) served under an enlisted rank during the war, one third of the total group had less than two years of previous service experience in the Australian armed forces and, for 45%, the Korean War was their only career deployment to a major military conflict.
Whilst the 6,122 participating Korean War veterans represented approximately 81% of male veterans who were identified as alive and residing in Australia in 2004, they also comprised only 34% of all male Australian armed forces personnel who were deployed to the Korean War. The majority of Australia’s Korean War veterans (approximately 57%) were deceased at the time of the Health Study.
The participating Korean War veterans differ from the original Korean War veteran group of almost 18,000 personnel, in regard to some known demographic and military characteristics.
Participating veterans were, on average, very slightly younger at the time of the Korean War deployment than the original group (median age 23 years versus 24 years respectively). More notably, the age range at the time of deployment differs between the two groups; the participating study group ranged in age from 16 to 47 years at the time of deployment, whilst the original group ranged from 14 to 59 years.
The participating Korean War veterans were less likely than the original veteran group (17% versus 30% [19] respectively) to have deployed to World War II, and more likely (14% versus 9% [19] respectively) to have deployed to the Vietnam War.
Further, the participating study group comprised 55% Army veterans, whereas 61% of the original deployment were Army personnel.
These differences between the two groups reflect the fact that veterans who were older at the time of the Korean War have been more likely to die than younger veterans, and that Korean War Army veterans have experienced a higher mortality rate than Navy and Air Force veterans. [19]
The participating, surviving Korean War veterans in this Health Study, therefore, are not entirely representative of the original Australian Korean War veteran population. Consequently, the health patterns and lifestyle behaviours observed in the participating veterans in the Health Study may not necessarily reflect those which may have been observed if the entire veteran group had been studied while alive.
The Health Study results, however, will be complemented and informed by the findings of the Australian Korean War veterans’ Mortality [19] and Cancer Incidence [20] Studies and, together, the three studies will provide comprehensive information about the health of the entire veteran group.
Health outcomes in Korean War veterans and the comparison group
The results of the study showed that, approximately five decades after the Korean War, surviving veterans are experiencing markedly poorer psychological health, physical health, life satisfaction and quality of life, compared with a group of similarly aged Australian men who were residing in Australia at the time of the Korean War. The results also show that surviving Korean War veterans report a lifetime pattern of excess alcohol and tobacco consumption.
Psychological disorders; anxiety including PTSD, and depression
The two study groups differed markedly on measures of psychological morbidity, with Korean War veterans substantially more likely to report symptoms meeting criteria for anxiety, PTSD and depression.
Korean War veterans (26% or 33%, using two different cut-off scores for the Posttraumatic Stress Disorder Checklist (PCL)) were about six times more likely to meet criteria for PTSD than the comparison group. PTSD has been by far the most thoroughly investigated psychological health outcome in the international Korean War or WWII veteran health literature. Whilst reported prevalences of PTSD in studied veteran populations have been as low as 1% in veterans drawn from the US Normative Aging Study (NAS) [47, 53] and as high as 88% in Korean War POWs, [46] our findings are consistent with the majority of recent studies which report PTSD prevalences in the range of 24% to 32%. [40-43, 54, 166]
Importantly, few of these recent major studies have included comparison groups against which the results of the veterans could be directly compared. In our study, the 5% prevalence of comparison group subjects meeting PCL questionnaire criteria for PTSD was high compared with the 2.3% prevalence of PTSD previously reported in the Australian male community by the Australian Bureau of Statistics (ABS) 1997; [56] the latter study used DSM-IV criteria. This suggests that the PCL questionnaire results may represent an over-estimation of the true level of PTSD in both study groups. Even so, the magnitude of the difference between the two study groups provides compelling evidence that Australian Korean War veterans are experiencing markedly higher levels of PTSD than that which would be expected in Australian men of similar age and ethnic background.
The adverse impact of PTSD upon the lives of affected individuals can be significant, with chronic PTSD characterised by interacting groups of unpleasant and distressing symptoms including intrusive, avoidant and hyperarousal phenomena. These may include, for example, distressing memories, dreams or nightmares of the event, restricted range of affect and emotional responses, and irritability and/or sudden outbursts of excessive anger. [167] It is not unusual for PTSD to be accompanied by other physical, psychological and social problems, including comorbid depression, alcohol abuse and/or panic disorder, marital and family dysfunction, and worsened experience of physical disability from other medical problems. [167] As the affected Korean War veterans age, symptoms in many cases are likely to worsen rather than improve. [42, 167, 168] For example, Port et al (2001) [42] reported a PTSD symptom pattern of immediate onset after war deployment and gradual decline, followed by increasing PTSD symptoms among older survivors. The authors suggested that retirement could be an important developmental milestone contributing to PTSD symptom increases.
Treatment of PTSD requires a broad approach utilising pharmacological, psychological and social interventions. It is important to address both psychiatric and physical co-morbidities. Importantly, elderly sufferers from long-standing chronic PTSD can achieve symptomatic and functional improvement with appropriate treatment. [167]
As PTSD is an anxiety disorder, it is consistent that the study results also show Korean War veterans (31%) to be six times more likely than the comparison group to meet Hospital Anxiety and Depression (HAD) scale criteria for anxiety. It is not clear from the current analyses, however, the extent to which anxiety disorders other than PTSD affect Korean War veteran and comparison group participants.
Also using HAD scale criteria, Korean War veterans (23%) were shown to be about five times more likely than the comparison group to be suffering from depression. Like the PCL questionnaire, the HAD scale results may represent a slight overestimation of the true prevalence of both anxiety and depressive disorders in both study groups, as the observed prevalences in the comparison group are higher than those found in the ABS 1997 Survey. [56] Nonetheless, the magnitude of the differences between the Korean War veterans and the comparison group are large. Without treatment, depression can be a serious illness typically characterised by loss of enjoyment for life, lack of energy and concentration, and sleep and appetite disturbances. [56] It is associated with poor life satisfaction, [115] risk of suicide [66] and medication non-compliance which can complicate comorbid medical conditions. [123]
Depression is often found to co-occur with PTSD, however there is an overlap in symptom criteria between PTSD and depressive disorders and the literature is unclear as to whether depression may be related to trauma as part of PTSD itself, or whether it represents autonomous symptoms occurring separately from PTSD. [39] The distinction has important implications for clinicians in regard to the most appropriate psychological health interventions. Southwick et al (1991) [169] for example, found that depression co-occurring with PTSD among war veterans was more resistant to conventional anti-depressants and biologically and psychologically different from depression in the absence of PTSD. Further, Brewin et al (1993) [170] (cited in Hyer et al. 1999) [39] recommended adding a trauma processing component to standard cognitive therapy for depression. Effective interventions may be informed by further analysis to assess patterns of interrelationship between depressive and PTSD symptoms in Australia’s Korean War veterans. Clinicians caring for individual veterans may need to consider integrated intervention approaches which reflect the complexity of veterans’ prevailing symptoms.
Life satisfaction and quality of life
When asked how they felt about their life as a whole, taking into account what had happened in the last year and what was expected to happen in the future, Korean War veterans were less likely than the comparison group to report feeling delighted, pleased or mostly satisfied, and more likely to report feeling mostly dissatisfied, unhappy or terrible. Expressed as a Percent Life Satisfaction Score (PLS), Korean War veterans averaged 56%, well below (by approximately 0.5 of a standard deviation) the mean PLS score of 69% recorded by the comparison group. This finding is consistent with parallel findings of poorer physical and psychological health in these veterans, as these have both been shown to be closely associated with lower life satisfaction. [115] The comparison group mean score, in turn, was remarkably consistent with Cummins (1998) proposed universal norm of 70%, [118] and Dear, Henderson & Korten’s (2002) report of a 70.4% mean PLS score in Australian adults. [115]
Using the broader World Health Organisation brief Quality of Life (WHOQOL-Bref) measure, Korean War veterans recorded poorer scores than the comparison group on several dimensions of overall quality of life. The WHOQOL Group defined quality of life as individuals’ perceptions of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns; it is a subjective evaluation that is embedded in a cultural, social and environmental context. [113] Poorer scores for Korean War veterans comprised their assessments of poorer physical health (including ability to perform activities of daily living and mobility), psychological functioning (including self-esteem, concentration, negative mood, and body image), social relationships (including personal relationships and social support) and environment (including financial resources, transport, safety, and access to information). Consistent with the above findings, Korean War veterans were more likely than the comparison group to rate their quality of life as very poor, or poor, and to report dissatisfaction with their health.
Smoking patterns
Korean War veterans reported a lifetime pattern of tobacco smoking in excess of that reported by the comparison group. Korean War veterans were much more likely to be current smokers or former smokers, and more likely to have smoked in higher quantities, or for longer durations.
The increase in overall smoking exposure in Korean War veterans compared with the comparison group, particularly in former smoking history, may be in part associated with the fact that during the Korean War “cigarettes were freely available in large numbers” (p. 07). [20] Irrespective of the cause, the Korean War veterans’ increased exposure to tobacco smoking over time has increased their risk of multiple diseases associated with smoking. Indeed tobacco smoking is the risk factor considered responsible for the greatest burden of disease in older Australians. [66]
The Australian Korean War veterans’ Mortality Study (2003) [19] found that veterans had been dying at a higher rate than expected, based on rates in the Australian male population. This included elevated death rates from cancers, some of which are associated with smoking. It could be assumed, therefore, that some of Australia’s deceased Korean War veterans may have smoked at even higher rates than the surviving Korean War veterans who participated in the Health Study. If the total Korean War veteran population could have been included in the Study, it is possible that the observed increase in smoking exposure, relative to the comparison group, would have been greater in magnitude.
Our comparison group was restricted to participants who were residing in Australia at the time of the Korean War. Therefore the ethnic composition of the comparison group is slightly different to that of the average, current ageing Australian male population which includes men who have arrived from other countries more recently than the 1950s. As smoking patterns are known to vary significantly across different ethnic groups, it was particularly important to this measure that our comparison group was as similar as possible in terms of ethnic background to the Korean War veterans.
Compared with data from the Australian 1995 National Health Survey, [171] Korean War veterans (21%) were a little less likely to have never smoked than average Australian men aged 65 and above (27%), whilst the comparison group (40%) were much more likely to have never smoked. Also compared with the Australian 1995 Survey, [171] both Korean War veterans (12%) and the comparison group (7%) were less likely than Australian men aged 65 and above (15%) to be current smokers. The difference between our comparison group results and the National Health Survey results may reflect their different ethnic group composition, and this highlights the importance of using appropriately selected comparison groups in veteran studies in preference to comparisons with national normative data.
Alcohol consumption
Korean War veterans reported a pattern of lifetime and current alcohol consumption in excess of that reported by the comparison group.
Korean War veterans were slightly more likely to report being current alcohol drinkers, much more likely to report drinking in higher volumes and more likely to report binge drinking than the comparison group. Combined, these factors made the Korean War veterans more likely to be meet AUDIT-C questionnaire criteria for current “hazardous” drinking.
Korean War veterans were also more likely than the comparison group to meet CAGE questionnaire criteria for a history of alcohol related problems indicative of dependence and/or abuse at some point in their lifetime, to have considered themselves heavy drinkers, and to report having been treated for alcoholism or drinking problems.
In both study groups the percentages of subjects meeting CAGE questionnaire criteria for a history of lifetime alcohol problems (36% of Korean War veterans versus 14% of the comparison group) were higher than expected based on previous veteran literature. Other veteran studies using the CAGE questionnaire have reported lifetime alcohol problems in 9% to 19% of participating WWII or Korean War veterans from the US [43, 47, 49] and in 4% of non-veteran, mixed sex US controls. [49] However, using DSM-III criteria, other studies have reported lifetime alcohol abuse or dependence in between 25% and 34% of non-POW US WWII or Korean War veterans [46, 48] and in 24% of age-matched US non-veteran controls. [48]
The percentages of subjects meeting AUDIT-C questionnaire criteria for current hazardous drinking (45% of Korean War veterans and 31% of the comparison group) is also unexpectedly high in both study groups. The ABS (1997) [56] estimated current substance use disorders using DSM-IV criteria (including alcohol and drug use disorders) to occur in only 2.1% of Australian males aged 65 and over. Current risky alcohol consumption, as assessed in the Australian 2001 National Drug Strategy Household Survey, [62] was estimated to occur in only 7.7% of men aged 65-74 and in 3.3% of men aged 75 or over. Our finding of hazardous drinking in 31% of the comparison group appears to be an over-estimation of the likely, true level of drinking in this group based on the above figures for the Australian aged male population. If so, a similar over-estimation is likely to be affecting the Korean War veteran results.
Whilst the measures of alcohol consumption used in this study may be overestimating the true levels of drinking or alcohol disorders in both study groups, the important observations are those reflecting the magnitude and direction of the differences between the Korean War veterans and the comparison group. Our measures consistently indicated that Korean War veterans have been at higher risk of lifetime alcohol problems, and of currently drinking in higher amounts, than the comparison group.
By maintaining a lifetime pattern of increased alcohol consumption, Korean War veterans have placed themselves at increased risk of multiple health outcomes associated with long-term excessive alcohol consumption, including liver disease, pancreatitis, diabetes and cancers, accidental injury and adverse interactions with medications. [66]
Current medical conditions and hospitalisations
Fifteen medical conditions included in the participant questionnaire were all reported one and a half to three times more frequently by Korean War veterans than the comparison group. These included asthma, high blood pressure, stroke (or after effects of stroke), heart attack or angina, rapid or irregular heart beat, liver disease, arthritis, kidney disease, diabetes, melanoma, other skin cancer, other cancer (not skin), stomach or duodenal ulcer, partial or complete blindness (not corrected by glasses) and partial or complete deafness.
The pattern of excess medical conditions in Korean War veterans is consistent with findings of the Australian Korean War veterans’ Mortality and Cancer Incidence Studies which found excess cancers including melanoma, [20] and excess mortality associated with cancer, respiratory diseases, digestive diseases and with diseases of the circulatory system including ischaemic heart disease and stroke. [19] Excesses in several self-reported medical conditions are also consistent with veterans’ increased exposure to tobacco and alcohol as described earlier.
Our findings rely on self-report of medical conditions without elucidation of symptom patterns or medications, without further evaluation in a clinical setting and without validation using medical records. Some previous studies have shown that self-report of medical conditions can be unreliable. [172, 173] Where we have been able to compare the observed comparison group prevalences with alternative sources of normative Australian data, we have found some striking similarities and some differences. The ABS (1999) [149] report complete or partial deafness in 42%, and arthritis in 53%, of men aged 75 years and over, these figures being very close to those found in our comparison group (41% and 51% respectively). In contrast the ABS (1999) [149] report prevalences of 9% for diabetes, 7% for asthma and 35% for hypertension in men aged 75 years and over, all lower than the prevalences observed in our comparison group (15%, 11% and 43% respectively).
There are several possible explanations for the observed differences in the prevalence of medical conditions between the ABS study populations and our study comparison group. The ABS typically surveys members of households, thereby excluding Australians who are hospitalised or in nursing homes or similar institutions. Our comparison group may have included hospitalised or institutionalised participants, and their inclusion may explain higher than ‘normal’ prevalences of some medical conditions. Some health differences between the ABS study populations and our study comparison group may also be related to the different ethnic composition of the comparison group compared with the normal Australian population. Alternatively, some differences may be related to over-reporting of medical conditions which can occur if participants mistakenly report medical conditions which they don’t have. For example, the Korean War veteran group reported an unexpectedly high 21% prevalence for melanoma, a figure well in excess of findings from the Australian Korean War veterans’ Cancer Incidence Study [20] which found melanoma occurred in less than 2% of veterans. This over-reporting may be due to veterans confusing melanoma with basal or squamous cell skin carcinomas or benign skin lesions which may have been treated or removed by their doctors. Some over-reporting of this kind may be affecting the results for some medical conditions in both study groups.
The possibility of over-reporting of medical conditions means that we cannot be fully confident in the validity of all of the absolute prevalences observed in our two study groups. We prefer, therefore, to focus on the magnitude and direction of the differences observed between the Korean War veterans and comparison group in relation to self-reported medical conditions, and not the prevalences in each group. Importantly, the two previous studies of cancer incidence and causes of death in Korean War veterans give more reliable information for some medical conditions, because they match the groups against National cancer and death registries which contain very reliable information on these conditions. [19, 20]
Korean War veterans (35%) were more likely than the comparison group (26%) to report being hospitalised overnight at least once in the previous 12 months. Amongst those hospitalised, Korean War veterans reported slightly more nights of hospitalisation however this difference did not meet statistical significance after adjustment for covariates. The average number of nights hospitalised in both study groups was similar to the average length of hospital stay reported by the AIHW (2002) for Australian men aged 65 and above. [66] Self-reported hospitalisations in this study were not verified against hospital or claims data, and overnight hospitalisation or length of stay in hospital is not necessarily an indicator of the severity of illness. [66] Nevertheless, the increased rate of hospitalisation reported by veterans is consistent with the overall pattern of poorer physical and psychological health evident from other results in this study and those of the Mortality [19] and Cancer Incidence [20] Studies. Such increased hospitalisation rates can have important resource implications when planning health service utilisation for this veteran group.
Korean War deployment characteristics and their association with veterans’ health
Several investigated characteristics of the Korean War deployment, in particular increasing combat exposure severity and low rank, were strongly associated with current ill-health, and poor life satisfaction and quality of life in Korean War veterans.
Combat exposure
Increasing level of combat severity reported in relation to the Korean War was strongly associated with increased likelihood of current PTSD, anxiety, and depression, with current hazardous drinking and with history of alcohol related problems, with lower life satisfaction and with poorer quality of life.
Previous literature has frequently reported PTSD to be associated with increasing severity of combat or war-trauma exposure, [40, 41, 46, 53] and our study provides evidence of this association persisting very strongly some fifty years after the war. The conventional interpretation is that the stressful exposures are a central risk factor for the onset of symptoms. [174] However multiple additional factors are then thought to contribute to symptom persistence, or chronicity. [167]
The possibility of recall bias must be addressed in relation to our finding of an association between current ill-health and recall of increased combat severity in a war which occurred five decades earlier. It may be the case that memory of stressful experiences undergoes modification over time due to the presence of psychological or other adverse health symptoms. In a longitudinal study of UK Gulf War veterans, Wessely et al (2003) [175] found that recall of military hazards after conflict was not static and was associated with current self-rated perception of health. One possibility is that those individuals who have PTSD, for example, remember the events more accurately than those without the disorder. [176] Alternatively recall of threat or fear may become magnified with time in individuals who are symptomatic. [177] We were limited in our ability to assess the validity of our retrospectively collected combat exposure data, however we were able to gain some confidence in the data from our observations that some of the patterns of reported combat severity were in expected directions. For example, Army veterans and veterans who served during the mobile and/or static phases of the Korean War were much more likely to report moderate to heavy combat exposure than Navy or Air Force veterans or veterans who first deployed after the armistice, and Officers were slightly more likely than veterans of lower ranks to report no combat.
Figure A shows the pattern of association between combat exposure and PTSD, anxiety, and depression in Korean War veterans.
Figure A. Percentage of Korean War veterans with PTSD, anxiety, or depression across levels of combat exposure
Rank
Decreasing seniority in terms of rank at the time of the war, was also strongly associated with adverse health outcomes in Korean War veterans. Veterans who served with enlisted ranks were most likely, non-commissioned officers were less likely, and officers were least likely, to meet criteria for current PTSD, anxiety, depression, and history of alcohol related problems, and to report low life satisfaction and poor quality of life.
Consistent with our findings, lower rank has also previously been shown to be associated with increased psychological distress in British WWII and Korean War veterans, [40] and with both psychological and physical ill health in US Gulf War veterans [178] but the reason for these associations is unclear. In relation to the Korean War experience, our data showed that combat severity, using the Combat Exposure Scale (CES), did not differ markedly according to rank. Also, the association between rank and ill-health in Korean War veterans persisted after statistical adjustment for age. Therefore, some other characteristic of war deployment related to low rank may be contributing to subsequent health. It is possible that there are rank-related differences in the experience of combat that the CES is not able to detect. For example, in our recent research with Australia’s Navy Gulf War veterans using the Military Service Experience Questionnaire we found that lower ranked veterans reported more dangerous duties, experienced more helplessness associated with an inability to protect self or others from harm, and greater fear of attack, injury or death, than higher ranked veterans. [106] Lower rank may be associated with fewer years of armed forces experience prior to the Korean War deployment and this, in turn, was shown to be marginally associated with increased PTSD, anxiety, depression and history of alcohol related problems in our veteran participants. Other military service related factors such as access to strategic information, knowledge about the combat zone, type of military training, and personnel selection criteria such as demonstrated leadership, personality hardiness and coping skills may all vary on average across ranks and contribute to psychological vulnerability or resistance to negative war outcomes.
Some of the association between rank and ill-health may not be directly related to military service or Korean War deployment. Rank could be a proxy for socioeconomic status, [178] which is associated with both psychological and physical morbidity in civilian populations. [123, 179] Our statistical adjustment for education may not have fully controlled for other socioeconomic or related health risk factors which may be associated with rank, such as other formal qualifications, non-military income, employment level and associated job control, social support, unhealthy lifestyle behaviours or access to medical resources.
Figure B shows the pattern of association between rank and PTSD, anxiety, and depression in Korean War veterans.
Figure B. Percentage of Korean War veterans with PTSD, anxiety, or depression across levels of rank
Associations between other Korean War deployment characteristics and ill-health were more pronounced in relation to psychological health measures than they were in relation to life satisfaction and quality of life measures.
Service branch
Service branch was most notably associated with current PTSD, anxiety, depression and history of alcohol related problems, with Army veterans most likely, Navy veterans less likely and Air Force veterans least likely to meet criteria for these problems. Army veterans also consistently reported the lowest life satisfaction and poorest quality of life, however the magnitude of these differences across Service branches was small.
Like rank, the observed association between psychological ill-health and Army Service in Korean War veterans may reflect a combination of military service-related differences between the Army, Navy and Air Forces Service, or non-military differences such as socioeconomic factors or health behaviours. The pattern of elevated ill-health amongst surviving Army veterans is consistent with the pattern of elevated mortality and cancer incidence in Army veterans, compared with Navy and Air Force veterans, which was demonstrated in the previous Australian Korean War veteran Mortality [19] and Cancer Incidence [20] Studies.
Being wounded in action
Report of being wounded in action was strongly associated with current PTSD, anxiety, and depression, and more weakly associated with alcohol related problems and poorer life satisfaction. The type of evacuation reported for the injury or illness, which may be indicative of severity, was not associated with these health outcomes.
Veterans were not given an official definition for “wounded in action” in the questionnaire, and it was apparent that reports of being wounded in action possibly included various injuries, some possibly accidental, or illness requiring treatment, and not just wounds which were a direct result of enemy action or within close proximity to the battle line. It was observed that Army veterans who were officially listed by DVA as having been Wounded In Action (WIA) during Korea, reliably reported being wounded in the participant questionnaire. However, these officially WIA Army veterans represented less than half of all Army participants who reported being wounded.
Our finding of an association between report of being wounded in action in Korea, and current psychological disorders in Australian Korean War veterans, is somewhat consistent with Hunt & Robbins (2001) [40] finding of an association between war-related disability or illness and psychological distress in British WWII and Korean War veterans. Just a few years after the 1991 Gulf War, and the 1992-97 Bosnia conflict, Unwin et al (1999) [95] reported an association between combat-related injury and posttraumatic stress reaction, a multi-symptom syndrome, and physical functioning in British veterans of these more recent conflicts. Our findings, more than fifty years after the Korean War cease-fire, suggest that the associations observed by Unwin et al (1999) [95] in younger veterans could persist for an extremely long period of time into the future.
Korean War deployment era
Veterans who deployed to the Korean War during the mobile or static phases of the war, were consistently more likely to meet criteria for PTSD, anxiety and depression, than veterans who first deployed after the armistice (cease-fire). There were no consistent differences in health outcomes between veterans who first deployed during the mobile phase of the war, compared with veterans who first deployed during the static phase of the war.
Duration of Korean War deployment
Increased duration of Korean War deployment was most strongly associated with increased PTSD. Veterans who deployed for more than 12 months were 1.5 times more likely to have PTSD than veterans who deployed for less than 6 months. Increased duration of deployment was also moderately associated with anxiety, and history of alcohol related problems.
Similar findings, of associations between increased deployment duration and increased posttraumatic stress symptoms, have been observed in Vietnam War veterans from New Zealand, [180] and US soldiers deployed on a peacekeeping mission to Bosnia. [181]
Years of previous Australian armed forces service
Veterans who had fewer years of service experience prior to the Korean War were more likely to have PTSD, anxiety, and a history of alcohol problems than veterans who were more experienced. There was a 14%-16% increase in the prevalence of these disorders per categorical decrease in years of previous service experience from 4 or more years, to 1 to < 4 years, to < 1 year.
Age at time of deployment
Younger age at time of deployment (after statistical adjustment for current age), was associated with increased PTSD, anxiety and history of alcohol problems. Veterans who were aged 20 years or less at the time of deployment to the Korean War, for example, were approximately two times more likely to have PTSD, and 1.4 times more likely to have anxiety or a history of problem drinking, than veterans who were aged 31 years or older.
Deployment to major military conflicts in addition to Korea
Just over half of the participating Korean War veterans reported having been deployed to a major military conflict in addition to the Korean War. These Korean War veterans who had deployed to other major conflicts, however, did not report poorer health, poorer quality of life, or lower life satisfaction than other veterans who had not deployed to other conflicts.
Other Korean War deployment characteristics possibly associated with current health
There are a number of other Korean War deployment characteristics which may have impacted on the long term health of veterans, but which could not be directly investigated in this study.
The Korean War deployment experience included exposure to a number of environmental and chemical risk factors including extreme temperatures, rainfall and other climatic threats, multiple infectious disease sources, DDT and other insecticides, hydrocarbon combustion products, asbestos and petroleum fuel products. The participant questionnaire data showed that approximately 13% of surviving veterans reported having malaria as a result of their Korean deployment. A small number of participating veterans also reported haemorrhagic fever. However, there is little or no previously collected DVA, or Australian armed forces, data which can be used to systematically or accurately classify veterans in regard to their likelihood of exposure to other important environmental or chemical risk factors. As this Health Study was conducted so long after the Korean War, and as the questionnaire needed to be sufficiently short so as to be easily completed by the elderly study population, it did not attempt to retrospectively collect information on veterans’ exposure to environmental or chemical risk factors during Korea. Therefore, we were not able to assess the extent to which these exposures have impacted upon current health.
Similarly, the questionnaire did not attempt to retrospectively collect veterans’ experiences upon their return to Australia from Korea. The Korean War has been referred to as the ‘forgotten’ war with returning servicemen “greeted by a public that was apathetic to their deeds and sacrifices” (p.83). [22] Perceived rejection, and possible isolation from support services, including existing ex-service organisations, may have impacted upon veterans’ social adjustment upon return to civilian life. In Vietnam War veteran literature it is suggested that social rejection after discharge from service has contributed to ill health in this more recent veteran group. [182] Other aspects of post-war experience, for example ‘survivor guilt’ over having survived while others died, have been associated with later stress disorders. [183] There was not scope in this study for a detailed investigation of the health effects of post-Korean War experiences such as these.
Further, because only a small number of Australians (29 servicemen) were taken prisoner of war during the Korean War, the long-term health effects of this traumatic war time experience could not be investigated in the participating veteran group.
Overview of association between health outcomes and deployment characteristics
There are strong observed associations between ill-health and combat severity, low rank, Army Service and being wounded in action, and weaker observed associations with deployment during the mobile or static phases of the war, increased duration of Korean War deployment, younger age at time of deployment, and decreased years of previous armed forces service. There are also possible associations (though we are unable to measure these) with war-related chemical and environmental risk factors. Combined, these suggest a very complex inter-relationship between war service and subsequent, long-term ill-health. The overall picture appears to be one of combat severity and duration, war-related injury, a malevolent and/or toxic environment, inexperience, lack of seniority, possibly youthfulness, and perhaps socioeconomic disadvantage all contributing to long-term morbidity. There are likely to be other military and non-military characteristics, such as personality or social support, which have also contributed to veterans’ vulnerability to illness and the persistence of symptoms over time.
The Health Study findings in combination with those of the Australian Korean War veterans’ Mortality and Cancer Incidence Studies
It is important, in considering the overall health impact of Korean War service on Australian veterans, that the results of the Mortality, [19] Cancer Incidence, [20] and Health Studies be considered in combination. Overall, Korean War veterans have experienced a 21% higher mortality rate than other Australian men, [19] and between 13% and 23% higher cancer incidence. [20] Amongst survivors, psychological disorders appear to be particularly excessive, medical conditions and hospitalizations are also elevated, and quality of life and life satisfaction is poorer than that experienced by other Australian men.
An important factor relevant to the observations in the Health Study, potentially resulting in an underestimation of the total level of morbidity attributable to war service, is the Mortality Study finding that the Australian Korean War veteran population has experienced a higher mortality rate than the equivalent Australian male population. [19] The Health Study was limited to veterans who were alive in 2004, the survivors from a group who have been dying at a greater rate than their age-matched community peers. The Health Study, therefore, has not been able to detect the excess morbidity and adverse health outcomes associated with the increased rate of death.
Of great value to the interpretation of both the Mortality [19] and Cancer Incidence [20] Study findings, is new information about veterans’ cigarette and alcohol consumption which has been provided by the Health Study. Whilst smoking and alcohol data for deceased veterans is not available, the Health Study has shown that surviving veterans have been drinking and smoking at greater rates than a comparable sample of similarly aged Australian men.
The Cancer Incidence Study [20] found that Korean War veterans had elevated rates of several types of cancers for which smoking was a major-risk factor. Further analysis showed that the smoking prevalence rates in Korean War veterans would have to reach between 82% and 90% to explain observed cancer of the larynx ratios, 77% and 86% to explain cancer of the oesophagus ratios, and 59% and 64% to explain cancer of the lung ratios. In relation to head and neck cancers however, the analysis showed that even if 100% of veterans were smokers this would not explain the excess numbers. If we assume that deceased veterans have smoked in a similar pattern to surviving veterans or, more likely, at a higher rate, then our finding that 79% of surviving veterans report being former or current smokers may explain all of the excess lung cancers, many of the excess larynx and oesophagus cancers, and many but not all of the head and neck cancers previously observed in Korean War veterans.
In relation to alcohol, if a similar assumption is made that deceased veterans consumed alcohol in a similar, or more excessive, pattern to the survivors, then this may partly explain Mortality Study [19] findings of elevated mortality rates in Korean War veterans from specific causes of death including accidents and suicide, alcoholic liver disease and other digestive diseases.
The “healthy soldier” effect
There is a literature which would suggests that a “healthy worker” or “healthy soldier” effect, related to the exclusion of unfit persons from the armed forces, may partly conceal increased morbidity or mortality that should be attributed to war service. [184, 185] At the time of the Korean War, Australian armed forces volunteers were screened for their fitness to serve. Those who were accepted into the armed forces were those assessed as being in good health, with no chronic diseases or serious congenital anomalies, with no overt personality problems or behavioural disorders, no criminal record, and with IQ scores above 80. [19] Screened in such a away, and assuming no effect of war service or differences in post-war disease determinants, these Services personnel would be expected to have a lower risk of ill-health than the general male population.
In relation to our study of Australian Korean War veterans, the “healthy soldier” effect literature suggests that veterans would have been healthier than the comparison group at the time of deployment to the Korean War. Added to this observation is the reminder that the Health Study, limited to survivors, has been unable to detect excess morbidity and adverse health outcomes experienced by deceased veterans. In combination, these factors strongly suggest that the observed group differences in the direction of poorer health in veterans in the Health Study, actually represent an underestimation of the true magnitude of the differences which could be attributable to Korean War service.
Strengths and limitations of this study
The Health Study had various strengths which give confidence to the observed findings, but also some limitations which affect interpretation.
Unlike many recent studies which have used small or highly selected veteran groups, and which are, therefore, limited in their ability to extrapolate findings to the broader veteran community, a major methodological strength of our study has been the inclusion of the entire population of surviving Australian male Korean War veterans residing in Australia. The very low percentage of veterans recorded as not-contactable, and the excellent recruitment rate in this group, contribute to our confidence that the study results are very representative of the entire surviving population. Unlike most recent Korean War veteran health studies which have not included a civilian comparison group, another major strength of our study has been the inclusion of a large age-matched comparison group of Australian men who resided in Australia at the time of the war. This group provides an important bench-mark against which the health of the Korean War veterans can be usefully compared; providing important information about the extent of disease or ill-health in veterans which may be attributed to war service. Other methodological strengths contributing to confidence in our data include the use of well-validated instruments, where possible, for self-reported data, and DVA-held Nominal Roll data for some war-related service characteristics in preference to relying on veterans’ recall.
Methodological limitations to the Health Study include the reliance on self-reported health measures, particularly in relation to self-reported medical conditions, and the necessity for retrospective assessment of lifestyle and some deployment-related factors. Whilst these aspects of the study design can leave the study results vulnerable to recall bias, we were able to demonstrate some areas of internal consistency when self-reported data was compared with alternative objective data.
As the study was conducted so long after the Korean War, it did not attempt to retrospectively collect information on veterans’ exposure to environmental or chemical risk factors during Korea, which may have had important health implications. The scope of the study was further limited by the need for the questionnaire to be sufficiently short so as to be comfortably completed by elderly participants. Therefore, the study was not able to more broadly investigate additional military and non-military characteristics which may have contributed to veterans’ vulnerability to illness and the persistence of symptoms over time, such as personality, coping skills and income.
These limitations demonstrate the disadvantages of retrospective cross-sectional health study designs, and highlight the advantages of utilising longitudinal health study designs, which commence shortly after war deployment and follow veterans forward in time.
Conclusion
The Australian Korean War veterans’ Mortality, [19] Cancer Incidence, [20] and Health Studies combined present a compelling conclusion: that Korean War veterans have experienced post-war mortality and some cancers at excessive rates compared with similarly aged Australians, and that survivors continue to experience extremely poor psychological and physical health, a low level of life satisfaction and quality of life, and increased utilisation of health services. The Studies show that war service can have long-term, substantial effects on health which can persist fifty years after hostilities cease.
It is clear that some of the ill-health experienced by veterans is attributable to the severity of combat associated with Korean War service. Other military-related factors such as lack of seniority, inexperience, and war-related injury have also contributed to poor health. Non-military factors, such as socioeconomic disadvantage in the post-war period, have possibly also contributed to veterans’ vulnerability to poor health and persistence of symptoms over time. Finally, excessive tobacco smoking and alcohol consumption in the post-war period appear to be related to the Korean War deployment, and these lifestyle behaviours, in turn, have also had important adverse long term health effects.
Importantly, while past exposures and lifestyle factors cannot be changed, carefully planned health interventions may be effective in reducing ill-health experienced by Korean War veterans and in improving quality of life in their remaining years. In this regard, the results of this study should be useful in identifying the most appropriate health interventions, and levels of service provision, required by Australia’s surviving Korean War veterans.
More than fifty years after the war, however, less than 45% of Australia’s Korean War veterans remain alive. The deceased Korean War veterans cannot benefit from health interventions, or changes to health service provisions, which may arise from the findings of this study. Younger veterans of more recent conflicts, however, may benefit more from future studies if these can investigate deployment-related risk factors and health outcomes in closer proximity to the time of the deployment.
The results of the three Korean War veteran Studies could be viewed as providing a possible “snapshot” of the future health concerns faced by younger veterans of more recent conflicts. Indeed, the results of the Studies could be useful in identifying those veterans of more recent conflicts who may be at greatest risk of adverse health outcomes, and in developing appropriate strategies to prevent or reduce long-term ill-health in these veteran groups.
The Health Study, in combination with the Mortality [19] and Cancer Incidence [20] Studies, constitute a major study program of long term health in this Australian Korean War veteran population. This study program represents one of the most comprehensive investigations of health in an entire veteran group ever conducted internationally. The results will contribute substantially to the existing international body of knowledge on the long-term health effects of war deployment, and should assist in improving the health of future generations of military personnel, both in Australia and abroad.