title: Reliability, validity, and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index for elderly patients with a femoral neck fracture.
abstract: BACKGROUND
  The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been extensively evaluated in groups of patients with osteoarthritis, yet not in patients with a femoral neck fracture. This study aimed to determine the reliability, construct validity, and responsiveness of the WOMAC compared with the Short Form-12 (SF-12) and the EuroQol 5D (EQ-5D) questionnaires for the assessment of elderly patients with a femoral neck fracture.
  
  
  METHODS
  Reliability was tested by assessing the Cronbach alpha. Construct validity was determined with the Pearson correlation coefficient. Change scores were calculated from ten weeks to twelve months of follow-up. Standardized response means and floor and ceiling effects were determined. Analyses were performed to compare the results for patients less than eighty years old with those for patients eighty years of age or older.
  
  
  RESULTS
  The mean WOMAC total score was 89 points before the fracture in the younger patients and increased from 70 points at ten weeks to 81 points at two years postoperatively. In the older age group, these scores were 86, 75, and 78 points. The mean WOMAC pain scores before the fracture and at ten weeks and two years postoperatively were 92, 76, and 87 points, respectively, in the younger age group and 92, 84, and 93 points in the older age group. Function scores were 89, 68, and 79 points for the younger age group and 84, 71, and 73 points for the older age group. The Cronbach alpha for pain, stiffness, function, and the total scale ranged from 0.83 to 0.98 for the younger age group and from 0.79 to 0.97 for the older age group. Construct validity was good, with 82% and 79% of predefined hypotheses confirmed in the younger and older age groups, respectively. Responsiveness was moderate. No floor effects were found. Moderate to large ceiling effects were found for pain and stiffness scales at ten weeks and twelve months in younger patients (18% to 36%) and in the older age group (38% to 53%).
  
  
  CONCLUSIONS
  The WOMAC showed good reliability, construct validity, and responsiveness in both age groups of elderly patients with a femoral neck fracture who had been physically and mentally fit before the fracture. The instrument is suitable for use in future clinical studies in these populations.
  
  
  CONCLUSIONS
  The results are based on two clinical trials. The questionnaires used concern pure, clinically relevant issues (ability to walk, climb stairs, etc.). Moreover, the results can be used for future research comparing clinical outcomes (or treatments) for populations with a femoral neck fracture.
authors.affiliation: Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address for P.T.P.W. Burgers: p.t.p.w.burgers@erasmusmc.nl. E-mail address for T.M.J. Van Bakel: diederikvanbakel@live.nl. E-mail address for W.E. Tuinebreijer: w.tuinebreijer@erasmusmc.nl. E-mail address for S.M. Zielinski: s.zielinski@erasmusmc.nl. E-mail address for E.M.M. Van Lieshout: e.vanlieshout@erasmusmc.nl.
authors.forename: Paul T P W
authors.initials: PT
authors.lastname: Burgers
authors.affiliation: Joint Research, Department of Orthopaedic Surgery, Onze Lieve Vrouwe Gasthuis, P.O. Box 95500, 1090 HM Amsterdam, the Netherlands. E-mail address: rwp@jointresearch.org.
authors.forename: Rudolf W
authors.initials: RW
authors.lastname: Poolman
authors.affiliation: Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address for P.T.P.W. Burgers: p.t.p.w.burgers@erasmusmc.nl. E-mail address for T.M.J. Van Bakel: diederikvanbakel@live.nl. E-mail address for W.E. Tuinebreijer: w.tuinebreijer@erasmusmc.nl. E-mail address for S.M. Zielinski: s.zielinski@erasmusmc.nl. E-mail address for E.M.M. Van Lieshout: e.vanlieshout@erasmusmc.nl.
authors.forename: Theodorus M J
authors.initials: TM
authors.lastname: Van Bakel
authors.affiliation: Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address for P.T.P.W. Burgers: p.t.p.w.burgers@erasmusmc.nl. E-mail address for T.M.J. Van Bakel: diederikvanbakel@live.nl. E-mail address for W.E. Tuinebreijer: w.tuinebreijer@erasmusmc.nl. E-mail address for S.M. Zielinski: s.zielinski@erasmusmc.nl. E-mail address for E.M.M. Van Lieshout: e.vanlieshout@erasmusmc.nl.
authors.forename: Wim E
authors.initials: WE
authors.lastname: Tuinebreijer
authors.affiliation: Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address for P.T.P.W. Burgers: p.t.p.w.burgers@erasmusmc.nl. E-mail address for T.M.J. Van Bakel: diederikvanbakel@live.nl. E-mail address for W.E. Tuinebreijer: w.tuinebreijer@erasmusmc.nl. E-mail address for S.M. Zielinski: s.zielinski@erasmusmc.nl. E-mail address for E.M.M. Van Lieshout: e.vanlieshout@erasmusmc.nl.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Zielinski
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, HSC 2C, 1200 Main Street West, Hamilton, ON L8N 3Z5, Canada. E-mail address: bhandam@mcmaster.ca.
authors.forename: Mohit
authors.initials: M
authors.lastname: Bhandari
authors.affiliation: Department of Emergency Medicine, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address: p.patka@erasmusmc.nl.
authors.forename: Peter
authors.initials: P
authors.lastname: Patka
authors.affiliation: Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands. E-mail address for P.T.P.W. Burgers: p.t.p.w.burgers@erasmusmc.nl. E-mail address for T.M.J. Van Bakel: diederikvanbakel@live.nl. E-mail address for W.E. Tuinebreijer: w.tuinebreijer@erasmusmc.nl. E-mail address for S.M. Zielinski: s.zielinski@erasmusmc.nl. E-mail address for E.M.M. Van Lieshout: e.vanlieshout@erasmusmc.nl.
authors.forename: Esther M M
authors.initials: EM
authors.lastname: Van Lieshout
mesh_terms: D000043:Abstracting and Indexing; D000369:Aged, 80 and over; D005260:Female; D005265:Femoral Neck Fractures / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009864:Ontario; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards