title: Dynamic weight-bearing assessment of pain in knee osteoarthritis: a reliability and agreement study.
abstract: OBJECTIVE
  To evaluate the reliability, agreement and smallest detectable change in a measurement instrument for pain and function in knee osteoarthritis; the Dynamic weight-bearing Assessment of Pain (DAP).
  
  
  METHODS
  The sample size was set to 20 persons, recruited from the outpatient osteoarthritis clinic at Frederiksberg Hospital, Copenhagen. Two physiotherapists tested all participants during two visits; at the first visit, one single DAP (including four scores) was conducted by rater one; at the second visit, DAP was conducted by both raters one and two in randomized order with concealed allocation. The time interval was approximately 1.5 h. Measurement error was estimated by standard error of measurement (SEM). The intra- and inter-rater reliability was estimated by Intra-class Correlation Coefficients for agreement based on a two-way ANOVA with random effects (single measures ICC 2.1). Smallest detectable change (SDC) and limits of agreement were calculated.
  
  
  RESULTS
  The pain score showed excellent reliability in terms of ICC (intra-rater 0.93, CI 0.83-0.97, inter-rater 0.91, CI 0.78-0.96), low SEM (intra-rater 0.70, inter-rater 0.86, on a scale from 0 to 10), and acceptable SDC for intra-rater test (1.95). The three knee bend scores all had ICC above 0.50, showing fair-to-good reliability. None of the knee bend scores showed acceptable SEM and SDC.
  
  
  CONCLUSIONS
  The reproducibility of the DAP pain score meets the demands for use in clinical practice and research. The total knee bend could be useful for motivational purpose in clinical use. Testing of other psychometric properties of the DAP is pending.
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. Louise.Klokker.Madsen@regionh.dk.
authors.forename: Louise
authors.initials: L
authors.lastname: Klokker
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. robin.christensen@regionh.dk.|Faculty of Health Sciences, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. robin.christensen@regionh.dk.
authors.forename: Robin
authors.initials: R
authors.lastname: Christensen
authors.affiliation: Faculty of Health, Population Health Strategic Research Centre, School of Health and Social Development, Deakin University, Burwood, Australia. richard.osborne@deakin.edu.au.
authors.forename: Richard
authors.initials: R
authors.lastname: Osborne
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. elisabeth.marie.ginnerup-nielsen@regionh.dk.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ginnerup
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. eva.elisabet.waehrens@regionh.dk.|The Research Initiative for Activity studies and Occupational Therapy, Institute of Public Health, University of Southern Denmark, Odense, Denmark. eva.elisabet.waehrens@regionh.dk.
authors.forename: Eva E
authors.initials: EE
authors.lastname: Waehrens
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. henning.bliddal@regionh.dk.
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
authors.affiliation: The Parker Institute, Bispebjerg & Frederiksberg University Hospitals, Copenhagen, Denmark. marius.henriksen@regionh.dk.
authors.forename: Marius
authors.initials: M
authors.lastname: Henriksen
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000453:epidemiology* / Q000473:pathology; D010147:Pain Measurement / Q000379:methods*; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D016474:Weight-Bearing
keywords: Knee osteoarthritis; Measurement; Pain; Physical function