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Validity and reliability of the Japanese Orthopaedic Association score for osteoarthritic knees

  • Original Article
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Journal of Orthopaedic Science



A variety of outcome measures are available to evaluate physical impairment and disability in patients with knee osteoarthritis, and most physician-rated measures are not validated. The objective of this study was to assess the validity and reliability of an observer-based knee scoring system of the Japanese Orthopaedic Association (the JOA) commonly used in Japanese clinical practice, and to determine demographic variables affecting the score.


A consecutive series of 85 patients with primary knee osteoarthritis completed the JOA (four domains pain on walking, pain on ascending or descending stairs, range of motion, and joint effusion), two validated patient-rated measures including the generic instrument of the Medical Outcomes Study 36-Item Short-Form (the SF-36) Health Survey, and the disease-specific scale of the Japanese Knee Osteoarthritis Measure (the JKOM), and a performance based timed-up-and-go test (TUG). Concurrent validity was determined by examining correlations of the JOA with the SF-36 and the JKOM. Construct validity was verified by correlating each domain of the JOA with objective measurements of TUG using Spearman’s rank correlation coefficient. Intra- and interobserver reliability and internal consistency of the JOA were evaluated with another cohort of 32 patients who had a knee disorder at baseline and again at a mean of 18 days later.


The JOA was significantly correlated with validated patient-rated outcome measures (the JKOM, the SF-36), indicating concurrent validity of the JOA. Domains of the JOA had significant correlations with the TUG, showing adequate construct validity. Intra- and interobserver reliability for the JOA showed a moderate to almost perfect agreement, and internal consistency of Cronbach’s α indicated that the JOA score was a highly reliable instrument to assess knee osteoarthritis. As a demographic variable, age was highly correlated with the JOA.


The JOA, generally used as an observer-derived knee scoring system, is a valid and reliable tool for evaluating functional status in patients with knee osteoarthritis.

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  1. Conagham PG, Emerton M, Tennant A. Internal construct validity of the Oxford Knee Scale: evidence from Rasch measurement. Arthr Rheum. 2007;57(8):1363–7.

    Article  Google Scholar 

  2. Bellamy N, Buchanan W, Goldsmith CH, Campbell J, Stitt LW. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip and the knee. J Rheumatol. 1988;15:1833–40.

    PubMed  CAS  Google Scholar 

  3. Brasier JE, Harper R, Jones NMB, O’Cathain A, Thomas KJ, Usherwood T, Weslake L. Validating the SF-36 health survey questionnaire: new outcome measure for primary care. BMJ. 1992;305:160–4.

    Article  Google Scholar 

  4. Ware JE, Sherbourne CD. 36-Item Short-Form Health Survey (SF-36). I. Conceptual framework and item selection. Med Care. 1992;30:473–83.

    Article  PubMed  Google Scholar 

  5. Fukuhara S, Bito S, Green J, Hsiao J, Kurokawa K. Translation, adaptation, and validation of the SF-36 health survey for use in Japan. J Clin Epidemiol. 1998;51:1037–44.

    Article  PubMed  CAS  Google Scholar 

  6. Nelson FS, Allen PM, John GS, Gray RM. Evaluation of the construct validity of the DASH questionnaire by correlation with the SF-36. J Hand Surg [Am]. 2002;27:537–41.

    Article  Google Scholar 

  7. Akai M, Doi T, Fujino K, Iwata T, Kurosawa H, Nasu T. An outcome measure for Japanese people with knee osteoarthritis. J Rheumatol. 2005;32:1524–31.

    Google Scholar 

  8. Bombardier C, Melfi CA, Paul J, Green R, Hawker G, Wright J, Coyte P. Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery. Med Care. 1995;33:131–44.

    Google Scholar 

  9. Altman R, Asch E, Bloch D, Bole G, Borenstein D, Brandt K, Christy W, Cooke TD, Greenwald R, Hochberg M. Development of criteria for the classification and reporting of osteoarthritis. Classification of osteoarthritis of the knee. Diagnostic and Therapeutic Criteria Committee of the American Rheumatism Association. Arthr Rheum. 1986;29(8):1039–49.

    Article  CAS  Google Scholar 

  10. Söderman P, Malchau H. Validity and reliability of Swedish WOMAC osteoarthritis index: a self-administered disease-specific questionnaire (WOMAC) versus generic instruments (SF-36 and NHP). Acta Orthop Scand. 2000;71:39–46.

    Article  PubMed  Google Scholar 

  11. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33:159–74.

    Article  PubMed  CAS  Google Scholar 

  12. Cortina JM. What is coefficient alpha? An examination of theory and applications. J Appl Psychol. 1993, 98–104.

  13. Briggs KK, Lysholm J, Tegner Y, Rodkey WG, Kocher MS, Steadman JR. The reliability, validity, and responsiveness of the Lysholm score and Tegner activity scale for anterior cruciate ligament injuries of the knee. Am J Sports Med. 2009;37:890–7.

    Article  PubMed  Google Scholar 

  14. Söderman P, Malchau H. Is the Harris Hip Score System useful to study the outcome of total hip replacement? Clin Orthop. 2001;384:189–97.

    Article  PubMed  Google Scholar 

  15. Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc. 2000;48:104–5.

    Google Scholar 

  16. Martin DP, Engelberg R, Agel J, Swiontkowski MF. Comparison of the musculoskeletal function assessment questionnaire with the Short Form-36, the Western Ontario and McMaster Universities Osteoarthritis Index, and the Sickness Impact Profile health-status measures. J Bone Joint Surg Am. 1997;79:1323–35.

    PubMed  CAS  Google Scholar 

  17. Liang MH, Fossel AH, Larson MG. Comparisons of five health status instruments for orthopedic evaluation. Med Care. 1990;28:632–42.

    Article  PubMed  CAS  Google Scholar 

  18. Bessette L, Sangha O, Kuntz KM, Keller RB, Lew RA, Fossel AH, Katz JN. Comparative responsiveness of generic versus disease-specific and weighted versus unweighted health status measures in carpal tunnel syndrome. Med Care. 1998;36:491–502.

    Article  PubMed  CAS  Google Scholar 

  19. Rorabeck CH, Bourne RB, Laupacis A, Feeny D, Wong C, Tugwell P, Leslit K, Bullas R. A double-blind study of 250 cases comparing cemented with cementless total hip arthroplasty. Clin Orthop. 1994;298:156–64.

    PubMed  Google Scholar 

  20. Wright JG, Young NL. The Patient-Specific Index: asking patients what they want. J Bone Joint Surg Am. 1997;79:974–83.

    PubMed  CAS  Google Scholar 

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We wish to thank Akio Iida M.D. and Takumi Ohkawa M.D. for their assistance of the measurement. We are also grateful to all of the orthopaedic staff members in Ishinkai General Hospital.

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The authors did not receive and will not receive any benefits or funding from any commercial party related directly or indirectly to the subject of this article.

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Correspondence to Masayoshi Okuda.

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Okuda, M., Omokawa, S., Okahashi, K. et al. Validity and reliability of the Japanese Orthopaedic Association score for osteoarthritic knees. J Orthop Sci 17, 750–756 (2012).

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