Diagnosing Gout

Clinical Diagnosis of Gout

Patients: In a study of 381 patients recruited by family physicians because of monoarthritis, 57% had positive crystals and one patient had a bacterial infection.

Results: The family physicians had an accuracy of:

  • Sensitivity 97%
  • Specificity 28%

The authors then created a prediction rule for the 328 patients that the family physicians suspected had gout:

Male sex 2.0 points
Previous patient-reported arthritis attack 2.0 points
Onset within 1 d 0.5 points
Joint redness 1.0 points
MIP involvement  2.5 points
Hypertension or and cardiovascular diseases 1.5 points
Serum uric acid level >5.88 m9/dL  3.5 points

The prediction rule had an accuracy of:

  • 8 or more points
    • Sensitivity 92% (193/209)
    • Specificity 88% (77/88)
  • 4 or less points
    • Sensitivity 99% (208/209)
    • Specificity 50% (44/88)

If 4 or less points, the NPV is 98%.

If 8 or more points, the PPV=95%.

Comment: Even if using the prediction rule developed in this study, physicians should consider aspirating most all joints with monoarthritis as value even in joints suggestive of gout had a one in 20 chance of an alternative diagnosis. Also, the label of gout may affect future decision making and life-long medications.

References:

1. Janssens HJ, Fransen J, van de Lisdonk EH, van Riel PL, van Weel C, & Janssen M (2010). A diagnostic rule for acute gouty arthritis in primary care without joint fluid analysis. Archives of Internal Medicine, 170 (13), 1120-6 PMID: 20625017

2. Peláez-Ballestas I, Hernández Cuevas C, Burgos-Vargas R, Hernández Roque L, Terán L, Espinoza J et al. (2010) Diagnosis of chronic gout: evaluating the american college of rheumatology proposal, European league against rheumatism recommendations, and clinical judgment. J Rheumatol 37 (8):1743-8. DOI: 10.3899/jrheum.091385 PMID: 20551101.

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