Table 1

Previously published classification criteria for gout

Rome 1963 [6]New York 1966 [7]ARA preliminary classification criteria for acute gout 1977 [5]
Items
  1. Serum uric acid >7 mg/dL in men and >6 mg/dL in women
  2. Presence of tophi
  3. MSU crystals in SF or tissue
  4. History of attacks of painful joint swelling with abrupt onset and resolution within 2 weeks
  1. At least two attacks of painful joint swelling with complete resolution with 2 weeks
  2. A history or observation of podagra
  3. Presence of tophi
  4. Rapid response to colchicine treatment, defined as a major reduction in the objective signs of inflammation within 48 h
  1. More than one attack of acute arthritis
  2. Maximum inflammation developed within 1 day
  3. Oligoarthritis attack
  4. Redness observed over joints
  5. First MTP joint painful or swollen
  6. Unilateral first MTP joint attack
  7. Unilateral tarsal joint attack
  8. Tophus (suspected or proven)
  9. Hyperuricemia (more than 2 S.D. greater than the normal population average)
  10. Asymmetric swelling within a joint on X-ray
  11. Subcortical cysts without erosions on X-ray
  12. Complete termination of an attack
Case definitionTwo or more of any criteriaTwo or more of any criteria OR presence of MSU crystals in SF or on depositionSix of 12 clinical criteria required OR presence of MSU crystals in SF or in tophus
Limitations of these criteriaDeveloped based on expert opinionPhysician diagnosis considered to be the gold standard. MSU crystal identification was not used to define cases during development process.
Controls limited to patients with RA, acute calcium pyrophosphate crystal arthritis and acute septic arthritis—common mimickers such as OA, PsA, and reactive arthritis excluded.
SF examination performed in only 51 % of gout patients and in 47 % of the controls. Of the gout patients that underwent synovial analysis, only 84 % had MSU crystals identified.
Developed prior to availability of advanced imaging modalities.

ARA American Rheumatism Association, MSU monosodium urate, SF synovial fluid, MTP metatarsophalangeal, SD standard deviations, RA rheumatoid arthritis, OA osteoarthritis, PsA psoriatic arthritis