title: Family structure and posttraumatic stress reactions: a longitudinal study using multilevel analyses.
abstract: BACKGROUND
  There is limited research on the relevance of family structures to the development and maintenance of posttraumatic stress following disasters. We longitudinally studied the effects of marital and parental statuses on posttraumatic stress reactions after the 2004 Southeast Asian tsunami and whether persons in the same households had more shared stress reactions than others.
  
  
  METHODS
  The study included a tourist population of 641 Norwegian adult citizens, many of them from families with children. We measured posttraumatic stress symptoms with the Impact of Event Scale-Revised at 6 months and 2 years post-disaster. Analyses included multilevel methods with mixed effects models.
  
  
  RESULTS
  Results showed that neither marital nor parental status was significantly related to posttraumatic stress. At both assessments, adults living in the same household reported levels of posttraumatic stress that were more similar to one another than adults who were not living together. Between households, disaster experiences were closely related to the variance in posttraumatic stress symptom levels at both assessments. Within households, however, disaster experiences were less related to the variance in symptom level at 2 years than at 6 months.
  
  
  CONCLUSIONS
  These results indicate that adult household members may influence one another's posttraumatic stress reactions as well as their interpretations of the disaster experiences over time. Our findings suggest that multilevel methods may provide important information about family processes after disasters.
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies, Kirkeveien 166, Building 48, 0407 Oslo, Norway. egil.nygaard@nkvts.unirand.no
authors.forename: Egil
authors.initials: E
authors.lastname: Nygaard
authors.forename: Tore
authors.initials: T
authors.lastname: Wentzel-Larsen
authors.forename: Ajmal
authors.initials: A
authors.lastname: Hussain
authors.forename: Trond
authors.initials: T
authors.lastname: Heir
mesh_terms: D000328:Adult; D004190:Disasters; D005190:Family / Q000523:psychology*; D005260:Female; D006801:Humans; D008016:Life Change Events; D008137:Longitudinal Studies; D008297:Male; D008393:Marriage / Q000523:psychology; D055361:Multilevel Analysis; D009664:Norway; D010290:Parents; D011569:Psychiatric Status Rating Scales; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000453:epidemiology*; D057192:Tsunamis