title: Test-retest reliability of Common Mental Disorders Questionnaire (CMDQ) in patients with total hip replacement (THR).
abstract: BACKGROUND
  The Common Mental Disorders Questionnaire (CMDQ) is used to assess patients' mental health. It has previously been shown to provide a sensitive and specific instrument for general practitioner setting but has so far not been tested in hospital setting or for changes over time (test-retest). The aim of this study is, by means of a test-retest method, to investigate the reliability of the instrument over time with total hip replacement (THR) patients.
  
  
  METHODS
  Forty-nine hip osteoarthritis patients who had undergone THR answered the questionnaire twelve months after their operation. Fourteen days later they completed it again. Covering emotional disorder, anxiety, depression, concern, somatoform disorder and alcohol abuse, the questionnaire consists of 38 items with six subscales, each of which has between 4 to 12 items. A five-point Likert scale (from 0-4) is used.
  
  
  RESULTS
  For each of the 38 questions, a quadratic-weighted Kappa coefficient of 0.42 (0.68 - 0.16) to 0.98 (1.00 - 0.70) was found. A Cronbach's alpha of 0.94 for all the questions indicated high internal consistency.
  
  
  CONCLUSIONS
  The results showed a moderate to almost perfect reliability of CMDQ of this specific population.
  
  
  BACKGROUND
  Current Controlled Trials: NCT01205295.
authors: Department of Orthopaedic Surgery, Kolding Hospital, a part of Lillebaelt Hospital, Odense, Denmark ; Institute of Psychology, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark.
authors: Randi
authors: R
authors: Bilberg
authors: Emergency Department, Kolding Hospital, a part of Lillebaelt Hospital, Odense, Denmark.
authors: Birgitte
authors: B
authors: Nørgaard
authors: Institute of Psychology, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark.
authors: Kirsten Kaya
authors: KK
authors: Roessler
authors: Department of Orthopaedics and Traumatology, Odense University Hospital, Odense, Denmark ; Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors: Søren
authors: S
authors: Overgaard
keywords: CMDQ; Kappa; Mental disorders; Missing; Reliability; Test-retest