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Rheumatoid Arthritis Prediction Rule for Undifferentiated Arthritis

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Rheumatoid Arthritis Prediction Rule for Undifferentiated Arthritis

  • Indications
  1. Rheumatoid Arthritis Diagnosis
  • Criteria
  1. Points clc: Age (calculated points = AgeYrs * 0.02)
  2. Points 1.0: Female Gender
  3. Points 0.5: Small joints of hands or feet affected
  4. Points 0.5: Symmetric joints involved
  5. Points 1.0: Upper extremities affected
  6. Points 1.5: Upper and lowe extremities affected
  7. Points 1.0: Morning stiffness rated at 26-90 mm on a 100 mm visual analog scale
  8. Points 2.0: Morning stiffness rated at >90 mm on a 100 mm visual analog scale
  9. Points 0.5: Number of tender joints 4-10
  10. Points 1.0: Number of tender joints 11 or more
  11. Points 0.5: Number of swollen joints 4-10
  12. Points 1.0: Number of swollen joints 11 or more
  13. Points 0.5: C-Reactive Protein 5 to 50 mg/L
  14. Points 1.5: C-Reactive Protein >51 mg/L
  15. Points 1.0: Rheumatoid Factor positive
  16. Points 2.0: Anti-Citrullinated Protein Antibody positive
  • Interpretation
  • Based on total cummulative score tallied from above criteria
  1. Score 0.0 - 3.5: Percentage with RA at one year 0% (LR 0)
  2. Score 3.5 - 6.5: Percentage with RA at one year 16% (LR 0.4)
  3. Score 6.5 - 8.5: Percentage with RA at one year 57% (LR 3.0)
  4. Score over 8.5: Percentage with RA at one year 85% (LR 12.7)
  • References
  1. van der Helm-van Mil (2007) Arthritis Rheum 56(2): 433-40 [PubMed]
  2. Mochan (2008) Am Fam Physician 77(10): 1451-3 [PubMed]