title: The factor structure of the hospital anxiety and depression scale in orthopedic trauma patients.
abstract: BACKGROUND
  Many instruments exist to assess mental disorders and anxiety, such as the hospital anxiety and depression scale (HADS). Nothing has been evaluated on the HADS factor structure for use with orthopedic trauma patients. The aim of this study was to validate the underlying structure of the HADS. Specifically, we sought to understand which of the factor structures found in the literature is appropriate for the orthopedic trauma patient population.
  
  
  METHODS
  This study included 348 patients with an average age of 49.8 years (SD: 18.4; range: 18 - 95). Confirmatory data analysis was performed to analyze the latent structure of the HADS. Akaike information criterion (AIC) was used to compare all the models, with the lowest AIC being the best fitting model.
  
  
  RESULTS
  We found that both the anxiety and the depression factors were highly correlated (with Pearson correlations greater than 0.700). After removing one item from each subscale, we found that a two-factor model was the best fitting one (AIC: 8,298.901); all other models had an AIC over 10,000.
  
  
  CONCLUSIONS
  Our results support a satisfactory two-factor structure for the HADS in the orthopedic trauma patients. Further studies are needed to test for higher factor structures in larger samples and in a different population.
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
authors.forename: Man
authors.initials: M
authors.lastname: Hung
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Bounsanga
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Tang
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Cheng
keywords: Anxiety; Depression; Factor analysis; HADS; Orthopedic; Trauma