title: Deployment, combat, and risk of multiple physical symptoms in the US military: a prospective cohort study.
abstract: OBJECTIVE
  Multiple physical symptoms (MPS) have historically been observed after deployment to a combat zone and are often disabling in nature. This study examined longitudinal trends in MPS status and its relationship to deployment in U.S. military service members.
  
  
  METHODS
  Using longitudinal data from panel 1 participants in the Millennium Cohort Study (n = 76,924), MPS status was assessed at three time points (2001-2008) using the 15-item Patient Health Questionnaire. Probability of reporting MPS was analyzed using mixed-effects multinomial logit regression, with time and deployment experience as main explanatory variables.
  
  
  RESULTS
  After adjustment for demographic, military, and health characteristics, service members who deployed with combat were significantly more likely to report MPS at each time point compared with those not deployed (odds ratio [OR] and 95% confidence interval [CI] for wave 1 = 1.49 [1.47-1.52], wave 2 = 1.73 [1.69-1.78], wave 3 = 2.08 [2.03-2.12]), and those who deployed without combat (OR and CI for wave 1 = 2.66 [2.59-2.74], wave 2 = 1.81 [1.75-1.87]; wave 3 = 1.68 [1.63-1.74]).
  
  
  CONCLUSIONS
  Longitudinal trends indicate that the probability of reporting MPS has increased consistently over time only for those deployed, regardless of combat experience.
authors.affiliation: Deployment Health Clinical Center, Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, Silver Spring, MD; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD. Electronic address: phoebe.mccutchan@gmail.com.
authors.forename: Phoebe K
authors.initials: PK
authors.lastname: McCutchan
authors.affiliation: Deployment Health Clinical Center, Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, Silver Spring, MD; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD; Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD.
authors.forename: Xian
authors.initials: X
authors.lastname: Liu
authors.affiliation: Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD; Deployment Health Research Department, Naval Health Research Center, San Diego, CA.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: LeardMann
authors.affiliation: Department of Community Health, School of Health and Human Services, National University, San Diego, CA.
authors.forename: Tyler C
authors.initials: TC
authors.lastname: Smith
authors.affiliation: Seattle Epidemiologic Research and Information Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Boyko
authors.affiliation: Behavioral and Policy Science, RAND Corporation, Arlington, VA.
authors.forename: Kristie L
authors.initials: KL
authors.lastname: Gore
authors.affiliation: Deployment Health Clinical Center, Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, Silver Spring, MD; Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Freed
authors.affiliation: Behavioral and Policy Science, RAND Corporation, Arlington, VA.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Engel
mesh_terms: D000328:Adult; D003130:Combat Disorders / Q000453:epidemiology*; D005260:Female; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008889:Military Personnel / Q000706:statistics & numerical data*; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D014857:Warfare
keywords: Cohort studies; Military medicine; Military personnel; Signs and symptoms; Veterans health