title: German translation, cross-cultural adaptation and validation of the whiplash disability questionnaire.
abstract: BACKGROUND
  The Australian Whiplash Disability Questionnaire (WDQ) was cross-culturally translated, adapted, and tested for validity to be used in German-speaking patients. The self-administered questionnaire evaluates actual pain intensity, problems in personal care, role performance, sleep disturbances, tiredness, social and leisure activities, emotional and concentration impairments with 13 questions rated on an 11-point rating scale from zero to ten.
  
  
  METHODS
  In a first part, the Australian-based WDQ was forward and backward translated. In a consensus conference with all translators and health care professionals, who were experts in the treatment of patients with a whiplash associated disorder (WAD), formulations were refined. Original authors were contacted for clarification and approval of the forward-backward translated version. The German version (WDQ-G) was evaluated for comprehensiveness and clarity in a pre-study patient survey by a random sample of German-speaking patients after WAD and four healthy twelve to thirteen year old teenagers. In a second part, the WDQ-G was evaluated in a patient validation study including patients affected by a WAD. Inpatients had to complete the WDQ-G, the North American Spine Society questionnaire (NASS cervical pain), and the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) at entry in the rehabilitation centre.
  
  
  RESULTS
  In the pre-study patient survey (response rate 31%) patients rated clarity for title 9.6 ± 0.9, instruction 9.3 ± 1.4 and questions 9.6 ± 0.7, and comprehensiveness for title 9.6 ± 0.7, instruction 9.3 ± 1.4 and questions 9.8 ± 0.4. Time needed to fill in was 13.7 ± 9.0 minutes. In total, 70 patients (47 females, age = 43.4 ± 12.5 years, time since injury: 1.5 ± 2.6 years) were included in the validation study. WDQ-G total score was 74.0 ± 21.3 points (range between 15 and 117 points). Time needed to fill in was 6.7 ± 3.4 minutes with data from 22 patients. Internal consistency was confirmed with Cronbachs's α = 0.89. Concurrent validity showed a highly significant correlation with subscale pain and disability (NASS) at r = 0.74 and subscale pain (SF-36) at r = 0.71.
  
  
  CONCLUSIONS
  The officially translated and adapted WDQ-G can be used in German-speaking patients affected by a WAD to evaluate patients' impairments in different domains. The WDQ-G is a self-administered outcome measure showing a high internal consistency and good concurrent validity.
authors.affiliation: Research Department Reha Rheinfelden, Salinenstrasse 98, 4310 Rheinfelden, Switzerland. c.schuster@reha-rhf.ch
authors.forename: Corina
authors.initials: C
authors.lastname: Schuster
authors.forename: Michael
authors.initials: M
authors.lastname: McCaskey
authors.forename: Thierry
authors.initials: T
authors.lastname: Ettlin
mesh_terms: D000293:Adolescent; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D005858:Germany; D017408:Guidelines as Topic; D006306:Health Surveys; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D013997:Time Factors; D014911:Whiplash Injuries / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation*