New Onset and Persistent Symptoms of Posttraumatic Stress Disorder Self Reported After Deployment and Combat Exposures: Prospective Population Based U.S. Military Cohort

Authors
Smith, T. C. Ryan, M. A . K. Wingard, D. L. Slymen, D. J. Sallis, J. F. Kritz-Silverstein, D.
Publication year
2007
Citation Title
New onset and persistent symptoms of post-traumatic stress disorder self-reported after deployment and combat exposures: Prospective population based U.S. Military cohort.
Journal Name
The British Medical Journal
Journal Volume
336
Issue Number
7640
Page Numbers
366-371
DOI
10.1136/bmj.39430.638241.AE.
Summary
Baseline and three-year follow-up data from Service members from all branches of the military were used to describe new onset and persistence of self-reported posttraumatic stress disorder (PTSD) symptoms in a large, population-based military cohort. New onset self-reported PTSD symptoms were identified in 8-9% of Service members who reported combat exposures during their deployment, 1-2% of Service members who deployed but did not experience combat, and 2-3% of those who did not deploy.
Key Findings
Overall, the rate of self-reported new onset symptoms of PTSD in deployed personnel was 4% compared to 2% in non-deployed personnel.
Participants who were female, divorced, enlisted, smokers, or problem drinkers at baseline experienced an increased risk of self-reported new onset symptoms of PTSD.
Deployed personnel who reported combat exposure were three times more likely to report new onset PTSD (8-9%) than those who did not deploy (2-3%).
Forty to fifty percent of participants who had PTSD symptoms at baseline reported PTSD symptoms at follow-up. Service members who were older, had higher levels of education, were officers, or were Marines were more likely to experience persisting symptoms at follow-up.
Implications for Program Leaders
Develop curricula for Service members to encourage healthy coping with symptoms of PTSD
Offer classes for military families regarding effective ways to support Service members with PTSD
Disseminate information regarding possible symptoms of mental health problems Service members may face after deployment and where individuals and families can find help for those problems
Implications for Policy Makers
Recommend military healthcare organizations and community programs partner to offer comprehensive supports for Service members with PTSD
Recommend education for service providers around the possible effects of deployment on Service members’ families
Encourage the integration of mental health education into existing service delivery systems for military families
Methods
Participants from the Millennium Cohort study who completed a baseline measure from July 2001-June 2003 and a three year follow-up measure between June 2004 and January 2006 were included in this study.
Demographic and military characteristics were obtained from the DoD Manpower Data Center.
Surveys asked questions about PTSD symptoms, smoking, drinking, and combat exposure.
Statistical analyses compared groups (such as those deployed and not deployed) on outcome variables.
Participants
Service members (N = 50,128) from all branches of the military were included.
Deployed Service member characteristics (n = 11,952; 24%) were as follows: 81% male, 41% born 1960-1969, 36% born 1970-1979, 65% married, 71% White, 48% bachelor’s degree or some college, 46% Army, 36% Air Force, 12% Navy/Coast Guard, 5% Marine Corps, 62% Active Duty, and 74% enlisted.
Non-deployed Service member characteristics (n = 38,176; 76%) were as follows: 70% male, 40% born 1960-1969, 28% born 1970-1979, 67% married, 71% White, 45% bachelor’s degree or some college, 48% Army, 28% Air Force, 20% Navy/Coast Guard, 4% Marine Corps, 53% Active Duty, and 72% enlisted.
No information on service branch was provided, although it was reported that the sample was representative of the U.S. Military as a whole.
Limitations
Researchers deliberately over sampled females, previously deployed personnel, and Reserve/National Guard personnel. Thus, the findings may not be representative of the military population in general.
Not all individuals who were selected to partake in the study agreed to participate. Hence, it is possible that those who chose to participate are different than those who did not, and findings may be biased.
All measures were self-report, which may have increased the likelihood of social desirability bias and/or recall bias.
Avenues for Future Research
Examine the relationships between resilience, deployment, combat exposure, and PTSD among Service members
Replicate this study using a validated measure of PTSD (as opposed to self-report)
Examine the extent to which length of time in military service impacts the relationship between deployment, PTSD, and other health outcomes
Design Rating
3 Stars - There are few flaws in the study design or research sample. The flaws that are present are minor and have no effect on the ability to draw conclusions from the data.
Methods Rating
2 Stars - There are no significant biases or deficits in the way the variables in the study are defined or measures and conclusions are appropriately drawn from the analyses performed.
Limitations Rating
2 Stars - There are a few factors that limit the ability to extend the results to an entire population, but the results can be extended to most of the population.
Focus
Multiple Branches
Target Population
Population Focus
Military Component
Abstract
To describe new onset and persistence of self-reported post-traumatic stress disorder symptoms in a large population based military cohort, many of whom were deployed in support of the wars in Iraq and Afghanistan. Design: Prospective cohort analysis. Setting and participants: Survey enrolment data from the millennium cohort (July 2001 to June 2003) obtained before the wars in Iraq and Afghanistan. Follow-up (June 2004 to February 2006) data on health outcomes collected from 50,184 participants. Main outcome measures: Self reported post-traumatic stress disorder as measured by the post-traumatic stress disorder checklist—civilian version using Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria. Results: More than 40% of the cohort were deployed between 2001 and 2006; between baseline and follow-up, 24% deployed for the first time in support of the wars in Iraq and Afghanistan. New incidence rates of 10-13 cases of post-traumatic stress disorder per 1000 person years occurred in the millennium cohort. New onset self-reported post-traumatic stress disorder symptoms or diagnosis were identified in 7.6-8.7% of deployers who reported combat exposures, 1.4-2.1% of deployers who did not report combat exposures, and 2.3-3.0% of non-deployers. Among those with self-reported symptoms of post-traumatic stress disorder at baseline, deployment did not affect persistence of symptoms. Conclusions: After adjustment for baseline characteristics, these prospective data indicate a threefold increase in new onset self-reported post-traumatic stress disorder symptoms or diagnosis among deployed military personnel who reported combat exposures. The findings define the importance of post-traumatic stress disorder in this population and emphasise that specific combat exposures, rather than deployment itself, significantly affect the onset of symptoms of post-traumatic stress disorder after deployment.
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