Baseline self reported functional health and vulnerability to post-traumatic stress disorder after combat deployment: prospective US military cohort studyBMJ 2009; 338 doi: http://dx.doi.org/10.1136/bmj.b1273 (Published 16 April 2009) Cite this as: BMJ 2009;338:b1273
- Cynthia A LeardMann, senior biostatistician1,
- Tyler C Smith, director1,
- Besa Smith, senior epidemiologist/biostatistician1,
- Timothy S Wells, medical chief epidemiologist2,
- Margaret A K Ryan, occupational and preventive medicine physician3
- for the Millennium Cohort Study Team
- 1Department of Defense Center for Deployment Health Research, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA
- 2Biosciences and Protection Division, Air Force Research Laboratory, Wright-Patterson Air Force Base, 2800 Q Street, OH 45433, USA.
- 3Naval Hospital Camp Pendleton, Box 555191, CA 92055, USA
- Correspondence to: C LeardMann
- Accepted 19 December 2008
Objective To determine if baseline functional health status, as measured by SF-36 (veterans), predicts new onset symptoms or diagnosis of post-traumatic stress disorder among deployed US military personnel with combat exposure.
Design Prospective cohort analysis.
Setting Millennium Cohort.
Participants Combat deployed members who completed baseline (2001-3) and follow-up (2004-6) questionnaires. Self reported and electronic data used to examine the relation between functional health and post-traumatic stress disorder.
Main outcome measures New onset post-traumatic stress disorder as measured by either meeting the DSM-IV criteria with the 17 item post-traumatic stress disorder checklist-civilian version or self report of a physician diagnosis at follow-up with the absence of both at baseline.
Results Of the 5410 eligible participants, 395 (7.3%) had new onset symptoms or diagnosis of post-traumatic stress disorder at the time of follow-up. Individuals whose baseline mental or physical component summary scores were below the 15th centile had two to three times the risk of symptoms or a diagnosis of post-traumatic stress disorder by follow-up compared with those in the 15th to 85th centile. Of those with new onset symptoms or diagnosis of post-traumatic stress disorder, over half (58%) of cases occurred among participants with scores below the 15th centile at baseline.
Conclusions Low mental or physical health status before combat exposure significantly increases the risk of symptoms or diagnosis of post-traumatic stress disorder after deployment. More vulnerable members of a population could be identified and benefit from interventions targeted to prevent new onset post-traumatic stress disorder.
In addition to the authors, the Millennium Cohort Study Team includes Lacy Farnell, Gia Gumbs, Isabel Jacobson, Molly Kelton, Travis Leleu, Jamie McGrew, Katherine Snell, Beverly Sheppard, Steven Spiegel, Kari Welch, Martin White, James Whitmer, and Charlene Wong, from the Department of Defense Center for Deployment Health Research, Naval Health Research Center, San Diego, CA; Paul J Amoroso, from the Madigan Army Medical Center, Tacoma, WA; Edward J Boyko, from the Seattle Epidemiologic Research and Information Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA; Gary D Gackstetter, from the Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, and the Analytic Services (ANSER), Arlington, VA; Gregory C Gray, from the College of Public Health, University of Iowa, Iowa City, IA; Tomoko I Hooper, from the Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda; and James R Riddle, from the US Air Force Research Laboratory, Wright-Patterson Air Force Base, OH. We are indebted to the Millennium Cohort Study participants, without whom these analyses would not be possible. We thank Scott L Seggerman and Greg D Boyd from the Management Information Division, US Defense Manpower Data Center, Seaside, CA; Michelle Stoia from the Naval Health Research Center; and all the professionals from the US Army Medical Research and Materiel Command, especially those from the Military Operational Medicine Research Program, Fort Detrick, MD. We appreciate the support of the Henry M Jackson Foundation for the Advancement of Military Medicine, Rockville, MD.
Contributors: All authors designed the study, analysed and interpreted the data, drafted and critically revised the manuscript, and approved the final version. CAL, TCS, and MAKR acquired the data. CAL, TCS, and BS carried out the statistical analysis. CAL is guarantor.
Funding: This represents Naval Health Research Center report 08-07, supported by the US Department of Defense, under work unit No 60002. Funding sources did not play any other role. The views expressed in this article are those of the authors and do not reflect the official policy or position of the US Department of the Navy, US Department of the Army, US Department of the Air Force, US Department of Defense, US Department of Veterans Affairs, or the US Government.
Competing interests: None declared.
Ethical approval: The Millennium Cohort Study was approved by the Institutional Review Board of the Naval Health Research Center (Protocol NHRC.2000.0007). All participants gave informed consent.
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