title: A comparative study of telephone versus onsite completion of the WOMAC 3.0 osteoarthritis index.
abstract: OBJECTIVE
  Outcome assessment in clinical trials using the Western Ontario and McMaster University (WOMAC 3.0) Osteoarthritis Index is traditionally achieved through self-administration of the Index. However, in other areas of clinical measurement, telephone administration has been shown to be a reliable method of acquiring data that are both accurate and complete. To address this issue in knee osteoarthritis (OA), we conducted a comparative study of telephone administration by interviewer of WOMAC LK3.0 versus onsite self-completion at the hospital.
  
  
  METHODS
  Fifty consenting patients with knee OA were randomized to complete the WOMAC LK3.0 Index by telephone interview one day, followed by onsite completion the following day, or vice versa. Neither patients nor interviewers had access to any prior scores.
  
  
  RESULTS
  The mean age of the 50 patients was 66.3 years (range 44-82); 34 (68%) were female and 16 (32%) male. There was excellent agreement between the mean office and telephone scores, with mean differences for the WOMAC LK3.0 pain, stiffness, and function subscale scores and total score of 0.09, 0.12, 0.78, and 0.98, respectively. These differences were well within the respective protocol defined equivalence criteria of +/- 1.7, +/- 0.9, +/- 6.4, and +/- 9.1, and represented differences from office scores of 0.9, 2.6, 2.4, and 2.2%, respectively.
  
  
  CONCLUSIONS
  The use of telephone interviews for the WOMAC LK3.0 Index is a valid method of obtaining OA outcome measurements. These observations have important implications for designing data acquisition strategies for future OA clinical trials and for longterm observational studies.
authors.affiliation: Centre of National Research on Disability and Rehabilitation Medicine, University of Queensland, Department of Medicine, Brisbane, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Bellamy
authors.forename: Jane
authors.initials: J
authors.lastname: Campbell
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hill
authors.forename: Philip
authors.initials: P
authors.lastname: Band
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006306:Health Surveys; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D017063:Outcome Assessment, Health Care; D010045:Outpatients; D011897:Random Allocation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires