Civilian casualty ratio
Some 7 million combatants on both sides are estimated to have died during World War I, along with an estimated 10 million non-combatants, including 6.6 million civilians. The civilian casualty ratio in this estimate would be about 59%. Boris Urlanis notes a lack of data on civilian losses in the Ottoman Empire, but estimates 8.6 million military killed and dead and 6 million civilians killed and dead in the other warring countries. The civilian casualty ratio in this estimate would be about 42%. Most of the civilian fatalities were due to famine, typhus, or Spanish flu rather than combat action. The relatively low ratio of civilian casualties in this war is due to the fact that the front lines on the main battlefront, the Western Front, were static for most of the war, so that civilians were able to avoid the combat zones.
Middle Eastern theatre of World War I
The significance of disease on this front can be best illustrated by comparing British the number of hospitalizations from disease/injury (frostbite, trench foot, etc.) in this theater to the Western Front. In France and Flanders, 2,690,054 British Empire troops were killed, wounded, died of wounds, missing, or captured, while there were 3,528,486 hospitalizations due to "non-battle casualties", a rate of 1.3 NBCs for every 1 battle casualty. In Mesopotamia there were 82,207 troops killed, wounded, died of wounds, missing, or captured, and 820,418 hospitalizations for sickness or injury, while in the Sinai and Palestine Campaign 51,451 men became battle casualties (not counting Indians) and 503,377 were hospitalized as non-battle casualties. In both cases, the rate is approximately 10 NBCs for every 1 battle casualty. Additionally, while by the listed numbers the Mesopotamia and Sinai-Palestine campaigns had only had 5% the battle casualties of the Western Front (136,658 v 2,690,054), they had over 70% of the disease deaths (22,693+ v 32,098).