title: Exploration of delayed-onset posttraumatic stress disorder after severe injury.
abstract: OBJECTIVE
  The first aim of this work was to conduct a rigorous longitudinal study to identify rates of delayed-onset posttraumatic stress disorder (PTSD) in a sample of patients with severe injury. The second aim was to determine what variables differentiated delayed-onset PTSD from chronic PTSD.
  
  
  METHODS
  Randomly selected patients with injury who were admitted to four hospitals around Australia were recruited to the study (N = 834) and assessed in the acute care hospital, at 3 months, and at 12 months. A structured clinical interview was used to assess PTSD at each time point.
  
  
  RESULTS
  Seventy-three patients (9%; n = 73) had PTSD at 12 months. Of these, 39 (53%) were classified as having delayed-onset PTSD. Furthermore, 22 (56%) patients with delayed-onset PTSD had minimal PTSD symptoms at 3 months (i.e., they did not have partial/subsyndromal PTSD at 3 months). The variables that differentiated delayed-onset PTSD from chronic PTSD were greater injury severity (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.02-1.26), lower anxiety severity at 3 months (OR = 0.73; 95% CI = 0.61-0.87), and greater pain severity at 3 months (OR = 1.39; 95% CI = 1.06-1.84).
  
  
  CONCLUSIONS
  Delayed-onset PTSD occurred frequently in this sample. Approximately half of the patients with delayed-onset PTSD had minimal PTSD symptoms at 3 months; therefore, their delayed-onset PTSD could not be accounted for by a small number of fluctuating symptoms. As we move toward DSM-V, it is important that research continues to explore the factors that underpin the development of delayed-onset PTSD.
authors.affiliation: Australian Center for Posttraumatic Mental Health, East Melbourne, VIC 3002, Australia. mod@unimelb.edu.au
authors.forename: Meaghan L
authors.initials: ML
authors.lastname: O'Donnell
authors.forename: Tracey
authors.initials: T
authors.lastname: Varker
authors.forename: Mark
authors.initials: M
authors.lastname: Creamer
authors.forename: Susan
authors.initials: S
authors.lastname: Fletcher
authors.forename: Alexander C
authors.initials: AC
authors.lastname: McFarlane
authors.forename: Derrick
authors.initials: D
authors.lastname: Silove
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bryant
authors.forename: David
authors.initials: D
authors.lastname: Forbes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D001930:Brain Injuries / Q000523:psychology; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D007902:Length of Stay / Q000706:statistics & numerical data; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010146:Pain / Q000209:etiology / Q000523:psychology*; D011446:Prospective Studies; D012307:Risk Factors; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology* / Q000209:etiology; D014947:Wounds and Injuries / Q000523:psychology*; D055815:Young Adult