Asymptomatic population reference values for three knee patient-reported outcomes measures: evaluation of an electronic data collection system and implications for future international, multi-centre cohort studies
The aim was to assess whether the Knee Society Score, Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were comparable in asymptomatic, healthy, individuals of different age, gender and ethnicity, across two remote continents. The purpose of this study was to establish normal population values for these scores using an electronic data collection system.
There is no difference in clinical knee scores in an asymptomatic population when comparing age, gender and ethnicity, across two remote continents.
312 Australian and 314 Canadian citizens, aged 18–94 years, with no active knee pain, injury or pathology in the ipsilateral knee corresponding to their dominant arm, were evaluated. A knee examination was performed and participants completed an electronically administered questionnaire covering the subjective components of the knee scores. The cohorts were age- and gender-matched. Chi-square tests, Fisher’s exact test and Poisson regression models were used where appropriate, to investigate the association between knee scores, age, gender, ethnicity and nationality.
There was a significant inverse relationship between age and all assessment tools. OKS recorded a significant difference between gender with females scoring on average 1% lower score. There was no significant difference between international cohorts when comparing all assessment tools.
An electronic, multi-centre data collection system can be effectively utilized to assess remote international cohorts. Differences in gender, age, ethnicity and nationality should be taken into consideration when using knee scores to compare to pathological patient scores. This study has established an electronic, normal control group for future studies using the Knee society, Oxford, and KOOS knee scores.
Level of evidence
Diagnostic Level II.
KeywordsAssessment Outcome Score Knee Arthroplasty Validation Oxford Electronic Automated Smartphone iPhone Laptop Joint Replacement
The authors would like to thank: Mami Okada, Research Assistant, University of British Columbia, for her help in the establishment of the study in Canada. Tara-Louise McLean, Research Assistant to Dr James McLean, for her help in the establishment of the study in Australia and Canada. Suzanne Edwards, Statistician, Data Management and Analysis Centre at the University of Adelaide, for her help with the statistical analysis of the collected data.
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. No sponsorship was sought. The investigators independently paid for a license to use the research software and database. The individual research tool registrations were paid for by OBERD Pty Ltd and are included as part of the licensing agreement.
Compliance with ethical standards
Conflict of interest
All named authors, their immediate families, and any research foundations with which they are affiliated, have no conflicts of interest to disclose and no commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
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