American Rheumatology Association, New York, and Rome prediction rules
A study of 82 Veterans Administration patients compared the American Rheumatology Association (ARA), New York, and Rome prediction rules with regard to their ability to diagnose gout with synovial urate crystals.6 The ARA criteria for gout diagnosis require either tophi or monosodium urate crystals in synovial fluid, or 6 out of a list of 12 other criteria.7
The New York prediction rule requires that patients meet 2 or more of the following criteria: at least 2 attacks of painful joint swelling with complete resolution within 2 weeks, podagra, tophi, and rapid response to colchicine treatment, defined as a major reduction in the objective signs of inflammation within 48 hours.
The Rome prediction rule requires meeting 2 of 3 criteria: serum uric acid >7 mg/dL in men and >6 mg/dL in women, presence of tophi, and history of attacks of painful joint swelling with abrupt onset and resolution within 2 weeks.
The New York prediction rule had the highest positive likelihood ratio of 4.4 compared with the ARA (1.8) and Rome (4.3) rules.6 The utility of the New York and Rome rules, although they have fewer criteria than ARA, is limited by the fact that they include a previous episode of joint swelling and tophi. These criteria increase their specificity but make them less useful in diagnosing a first episode of gout, when tophi are unlikely to have developed.
Prediction rules are more sensitive in established gout
The new ACR prediction rule was compared with the ARA, Rome, and New York clinical prediction rules using urate crystals as the gold standard in early (less than 2 years) and established disease (longer than 2 years).8 All clinical prediction rules were more sensitive in established disease than early disease (95.3% vs 84.1%; P<.001) and more specific in early disease than established disease (79.9% vs 52.5%; P<.001).