Combat and Trajectories of Physical Health Functioning in U.S. Service Members

Area of Science:

• Military medicine
• Public health
• Longitudinal studies

Background:

• Previous research links mental health trajectories to combat exposure in service members.
• Limited studies have explored the relationship between combat exposure and physical health trajectories.
• Understanding these physical health patterns is crucial for service member well-being.

Purpose of the Study:

• To investigate how combat exposure influences trajectories of physical health functioning in U.S. service members.
• To identify distinct patterns of physical health changes over time.
• To determine the association between combat exposure and these identified physical health trajectories.

Main Methods:

• Utilized data from 11,950 Millennium Cohort Study participants with index deployments between 2001-2005.
• Assessed self-reported physical health functioning five times between 2001-2016.
• Employed latent growth mixture modeling to identify longitudinal physical health trajectories and their relation to combat exposure.

Main Results:

• Identified five distinct physical health functioning trajectories: high-stable, delayed-declining, worsening, improving-worsening, and low-stable.
• Combat exposure was not associated with the shape of these trajectories but significantly influenced membership.
• Service members exposed to combat were more likely to follow less optimal trajectories (delayed-declining, worsening, low-stable) compared to those not exposed.

Conclusions:

• Combat exposure during military deployment is associated with poorer long-term physical health functioning trajectories.
• Despite negative associations, the most common trajectory for both combat-exposed and non-exposed personnel was high-stable physical health functioning.
• Findings highlight the resilience of service members while underscoring the detrimental impact of combat exposure on physical health over time.