title: Multisymptom Illness in Gulf War Veterans: A Systematic Review and Meta-Analysis.
abstract: The aim of this study was to conduct a systematic review and meta-analysis of multisymptom illness (MSI) in 1990 to 1991 Gulf/Afghanistan/Iraq War veterans.
  
  
  
  Electronic databases were searched from January 1990, June 2014 for studies on MSI prevalence in Gulf/Afghanistan/Iraq War veterans, based on the Centers for Disease Control and Prevention MSI case definition, and which included a military comparison group.
  
  
  
  Seven studies were identified among US, UK, and Australian Gulf War veterans; no studies were identified in Afghanistan/Iraq War veterans. MSI prevalence in Gulf War veterans and comparison groups ranged from 26 to 65% and from 12 to 37%, respectively. More recent studies were larger, with improved designs. The pooled odds ratio comparing Gulf War veterans to other military groups was 2.74 (95% confidence interval 2.15 to 3.51).
  
  
  
  The systematic review showed that MSI was most prevalent in Gulf War veterans, emphasizing the health burden of MSI in this veteran population.
authors.affiliation: Monash University, Department of Epidemiology and Preventive Medicine, Melbourne, Victoria, Australia.
authors.forename: Stella M
authors.initials: SM
authors.lastname: Gwini
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Forbes
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Sim
authors.forename: Helen L
authors.initials: HL
authors.lastname: Kelsall
mesh_terms: D047830:Gulf War; D006304:Health Status; D006801:Humans; D018923:Persian Gulf Syndrome / Q000453:epidemiology*; D015995:Prevalence; D014728:Veterans