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Knee OA clinical criteria (ACR: knee pain plus at least 3 of 6)

For: Knee osteoarthritis

A whole-joint condition in the knee, with loss of joint cartilage and changes in the underlying bone and surrounding tissues. Causes pain on use, stiffness and sometimes creaking (crepitus).

A weak test on its own
Sensitivity41%
Specificity75%
LR+ (positive)1.64
LR− (negative)0.79

LR− calculated from the published sensitivity and specificity; the study reported none.

What the numbers mean

  • Positive result: barely informative: a positive result changes little.
  • Negative result: barely informative: a negative result changes little.

Work out what a result means for your patient: probability calculator

Source

Peat G, Thomas E, Duncan R, Wood L, Hay E, Croft P. Clinical classification criteria for knee osteoarthritis: performance in the general population and primary care. Ann Rheum Dis. 2006;65(10):1363–1367. Journal article (DOI) · single study

Figures as they will appear in Rule It In, Rule It Out (Trokos, forthcoming). If a newer or better study changes them, this page changes with the book. Figures last updated from the book on 6 October 2026.

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