Abstract:
Background: Mental Health Disorders (MHDs) are a major cause of disability, are prevalent in military populations, and are increasing in the US military under current combat operations.1,2 Combat trauma ranks among the top risk factors for developing MHDs.3-6 MHDs are a leading cause for decreased medical readiness and military attrition,7 and increase risk for a variety of behavioral, occupational, and chronic health problems.1,2,8,9 In 1996, as part of a group of surveillance initiatives, the Department of Defense (DoD) mandated pre- and post-deployment health screening programs.10 This surveillance was expanded in 2005 to include a reassessment at 90-120 days after return from deployment, when research demonstrated a high rate of positive screens for MHDs using delayed survey approaches.11 Ft. Lewis combined an existing program, the Automated Behavioral Health Clinic, with these reassessments to create the Soldier Wellness Assessment Program (SWAP).12 SWAP exceeds the DoD mandate and is administered pre- and post-deployment to Soldiers who deploy from Ft. Lewis.
Objectives:
1. To ascertain the association between combat trauma and screening positive for MHDs.
2. To determine the operating characteristics and predictive value of a screening questionnaire for receiving a diagnosis for any or a group of MHDs.
Methods:
Data Sources: Responses from the SWAP automated 74-question survey instrument administered 120-45 days before and 90-120 days after deployment; health outcomes consisting of mental health related ICD-9 codes (290-317) from the Military Health System Management Analysis and Reporting Tool (M2). Participants: A population-based, retrospective cohort of 7100 Soldiers who deployed between 2005 and 2008 and who completed pre- and post-deployment surveys.
Measures: Exposures are assessed using a positive response to any of four combat trauma survey questions; outcomes are assessed from self-reported screening tools for PTSD, anxiety, depression, suicidality, aggression, alcohol abuse and from MHD-related ICD-9 codes assigned during clinical encounters within the first 12-months following deployment.
Analysis in Progress: The association between combat trauma and MHDs will be assessed using univariate methods and multivariate logistic regression models. The operating characteristics of these screening tools will be determined by comparing SWAP results against clinical diagnoses.
Discussion
Strengths include a representative cohort and comprehensive survey instrument allowing for generalizability and sub-analysis. Limitations include misclassification and recall bias inherent in self-report instruments.
The identification of risk factors predicting both a positive MHD screen and ICD-9 diagnosis will be valuable in validating the SWAP survey, providing evidence to guide decisions about extending the SWAP to other military installations.