title: Choosing appropriate comparison group participants in studies of veterans: Characteristics of orthopedically injured and uninjured Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn veterans.
abstract: BACKGROUND
  Research addressing deployment-related traumatic brain injury (TBI) is fairly complex due to a high prevalence of comorbid conditions, multiple exposures, and the lack of acute medical records. Therefore, there is a need for a well-defined, matching comparison group. This study compared deployment-related characteristics, everyday functioning, and cognitive performance in recently deployed veterans who had not sustained any injuries with those who had orthopedic injuries during deployment, but who were without a history of TBI.
  
  
  METHODS
  Participants included 45 individuals who had been deployed and who were without injuries and a group of 27 individuals who reported at least one orthopedic injury during deployment. The Mayo-Portland Adaptability Inventory-4, Community Integration Questionnaire, Veterans RAND 36 Item Health Survey, Brief Pain Inventory, Barratt Impulsiveness Scale-11, and posttraumatic stress disorder (PTSD) Checklist-Civilian (PCL-C) were used to assess daily functioning. Cognitive performance was measured using the Controlled Oral Word Association Test, Trail Making Test, Color-Word Interference Test, and Verbal Selective Reminding Test. The two groups were compared using t tests based on equal variances. The effect size was calculated.
  
  
  RESULTS
  There were no between-group differences, with all variables having p-values >.1 and small to medium effect sizes.
  
  
  CONCLUSIONS
  Orthopedic injuries sustained during deployment that did not require evacuation or hospitalization did not have any lasting effect on participants' health, cognition, and daily functioning relative to other deployed individuals with no history of injury. These results indicate the two groups are comparable and that their data could be potentially combined to create a single comparison group. Due to the small sample available for this study, the current results are considered preliminary, and further investigation is needed.
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|b Department of Physical Medicine and Rehabilitation , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Maya
authors.initials: M
authors.lastname: Troyanskaya
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|b Department of Physical Medicine and Rehabilitation , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Pastorek
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|b Department of Physical Medicine and Rehabilitation , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Randall S
authors.initials: RS
authors.lastname: Scheibel
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|c Department of Medicine , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Petersen
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|c Department of Medicine , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Annette
authors.initials: A
authors.lastname: Walder
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|b Department of Physical Medicine and Rehabilitation , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Helene K
authors.initials: HK
authors.lastname: Henson
authors.affiliation: a Michael E. DeBakey Veterans Affairs Medical Center , Houston , TX , USA.|b Department of Physical Medicine and Rehabilitation , Baylor College of Medicine , Houston , TX , USA.|d Department of Pediatrics , Baylor College of Medicine , Houston , TX , USA.|e Department of Neurosurgery , Baylor College of Medicine , Houston , TX , USA.|f Department of Psychiatry and Behavioral Sciences , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Levin
mesh_terms: D000328:Adult; D055826:Afghan Campaign 2001-; D001134:Arm Injuries / Q000503:physiopathology; D019567:Back Injuries / Q000503:physiopathology; D003071:Cognition / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D054542:Iraq War, 2003-2011; D007869:Leg Injuries / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D014728:Veterans; D014947:Wounds and Injuries / Q000503:physiopathology*; D055815:Young Adult
keywords: Comparison group; Functioning; Orthopedic injury; Veterans