Why is Marine combat mortality less than that of the Army?

Data from recent wars indicate that a wounded Marine had a 20% lower risk of dying than an Army soldier. Possible reasons for this difference are (1) Navy care is superior, (2) soldiers sustained more severe wounds, and (3) the services count casualties differently. Injury severity was measured in random samples of Marines and soldiers that were selected from the Wound Data and Munitions Effectiveness Team database. There was no difference in the lethality of injury and the prevalence of lifesaving first aid. Wounded Marines were more likely to wear protective vests, and this decreased Marine mortality in Vietnam. Hospitalized Marines had lower Injury Severity Scores and were less likely to be returned to duty without first being admitted to a medical treatment facility. Lower Marine combat mortality is primarily the result of the fact that a Marine with a minor soft tissue wound was more likely to be hospitalized than was a soldier with a similar injury.