Clinical diagnostic criteria for gout: comparison with the gold standard of synovial fluid crystal analysis.

BACKGROUND

Several classification or diagnostic criteria sets for gout have been proposed but none validated.

OBJECTIVE

This small pilot study considered urate crystal identification as the gold standard for diagnosis and compared the clinical aspects of 3 proposed criteria sets with that standard.

METHODS

Eighty-two subjects who had synovial fluid analyses in a VA medical center were studied. ARA (ACR), Rome, and New York clinical criteria sets and individual criteria were recorded in the 30 patients who had urate crystals versus the remainder with no urate crystals.

RESULTS

Presence of 2 of 3 Rome clinical criteria had the highest positive predictive value at 76.9%. None of the 3 studied criteria sets were more than 70% sensitive or 88.5% specific. The clinical features of the ARA (ACR) preliminary classification criteria had 70% sensitivity and 78.8% specificity.

CONCLUSIONS

The various proposed clinical criteria can provide support for a diagnosis or exclusion of gout, but unless improved criteria can be developed crystal identification should remain the gold standard.