Proposed definitions for disease flare in gout are based on self-reported items in patients with a previous diagnosis of gout. The definitions were created as a dimension of a composite gout response criterion; the intended application is for capturing gout flare events as outcomes of interest in studies of chronic gout and urate-lowering therapy.
Gaffo and associates collected data from 210 patients at 8 international sites to evaluate potential gout flare criteria against the gold standard of an expert rheumatologist definition. They developed flare definitions based on the presence of the number of criteria independently associated with the flare.
The presence of any patient-reported warm joint, any patient-reported swollen joint, a patient-reported pain-at-rest score higher than 3, and patient-reported flare were independently associated with the study gold standard. The greatest discriminating power was noted for the presence of 3 or more of the 4 criteria. Requiring all 4 criteria provided the highest specificity and positive predictive value. Pain at rest with a score higher than 3 was identified as the rule associated with the gold standard.
The authors noted that their gout flare definition should prove useful to researchers and clinicians who monitor flare frequency to improve patient care.