The GOUT-36 prediction rule for inpatient gout flare in people with comorbid gout: derivation and external validation.

Abstract

<h4>Objectives</h4>To develop and validate a gout flare risk stratification tool for people with gout hospitalised for non-gout conditions.<h4>Methods</h4>The prediction rule for inpatient gout flare was derived from a cohort of 625 hospitalised people with comorbid gout from New Zealand. The rule had four items: (1) no pre-admission GOut flare prophylaxis, (2) no pre-admission Urate-lowering therapy, (3) Tophus and (4) pre-admission serum urate >0.36 mmol/l within the previous year (GOUT-36 rule). Two or more items are required for the classification of high risk for developing inpatient gout flare. The GOUT-36 rule was validated in a prospective cohort of 284 hospitalised people with comorbid gout from Thailand and China.<h4>Results</h4>The GOUT-36 rule had a sensitivity of 75%, specificity of 67% and AUC of 0.71 for classifying people at high risk for developing inpatient gout flare. Four risk groups were developed: low (no items), moderate (one item), high (two items) and very high risk (three or four items). In a population with frequent (overall 34%) in-hospital gout flare, 80% of people with very high risk people developed flare, while 11% of low-risk people had inpatient flare.<h4>Conclusion</h4>GOUT-36 rule is simple and sensitive for classifying people with high risk for inpatient gout flare. The rule may help inform clinical decision and future research on the prevention of inpatient gout flare.