The study, published in the British Medical Journal, involved researchers from the University of Otago, Wellington (UOW), Kings College London, and Massey University.
The researchers randomly selected 350 soldiers who embarked on troopships in 1914, along with a comparison “non-combat” group of 350 who departed on troopships in late 1918 but for whom the war ended before they got to the frontlines.
A quarter of the 1914 group died during the war with injury deaths predominating (94 per cent) over disease deaths (six per cent).
The lifespan of the combat group, which included taking into account those killed in action or who died due to other causes during the war, was estimated at 65.9 years, compared to 74.2 years for the non-combat group – an eight-year difference. As well as warfare-related injury deaths, other causes of death included those from chemical weapons and various infectious diseases such as malaria and pandemic influenza.
The study also found that among survivors of the war, the 1914 veterans lived 1.7 years less.
Survivors in the combat group typically lived to 72.6 years compared to 74.3 years in the non-combat group.
Study co-author and Professor of War Studies at Massey University Glyn Harper says the reduced lifespan results for the combat-exposed group reflects the adverse impact of the rigours of the Gallipoli campaign in 1915 and trench warfare on the Western Front especially in 1916-1918.
“Even so, it is plausible our estimates would be even higher for the military personnel of some other participating nations which had even worse experiences than New Zealand soldiers – that is, where their soldiers were exposed to the particularly high mortality battles of 1914 and to major disease outbreaks of typhus and typhoid.”
Lead author of the study, Associate Professor Nick Wilson from the University of Otago Wellington, says further analysis of death certificate data suggested war-related causes such as suicide might have played a role too.
Another factor was the high burden of injuries, with an estimated 41 per cent of New Zealand soldiers receiving non-fatal wounds in the war. These injuries are likely to have increased the risk of death in subsequent surgical operations after the war and also death from cardiovascular disease, he says.
“From other wars we know that there is evidence that combat experience is a risk factor for post-traumatic stress disorder in veterans. This in turn is linked to an increased risk of coronary heart disease. (PTSD) is also associated with increased risk of suicide.”
While war-related death tolls for combatant nations of WWI are available, this appears to be the first study to provide estimates for the war-related life lost per participating soldier and for the veterans where an appropriate comparison group is used.
Professor Harper notes that New Zealand is well placed to carry out this type of study thanks to Auckland Museum’s Cenotaph database and Archives New Zealand’s excellent work digitalising military files, and with many other records now online.
“It was possible to find nearly all the dates of birth and deaths among these soldiers except for a few cases such as deserters and some who may have given a false name when joining the military – perhaps to escape debt collectors or unhappy marriages.”
An estimated 100,144 New Zealand military personnel served overseas in World War I, mainly on the Western Front, but also in campaigns in Gallipoli and Palestine. There were 16.6 per cent (16,700) who died during the war, with others dying subsequently raising the total to an estimated 18,311 by the end of 1923, Professor Harper says.
“This new study adds to our understanding of the impacts on those who went to this war – and also the continuing health burden borne by many of those who returned.”