Frequency and risk factors of gout flares in a large population-based cohort of incident gout.

OBJECTIVE: So far, few data are available to characterize the flare history of patients with gout. The objective of this study was to describe the frequency and risk factors of gout flares with special consideration of the comorbidity.

METHODS: A cohort study was conducted in a U.K. general practice database (The Health Improvement Network) including all patients aged 20-89 years diagnosed with incident gout between the years 2000 and 2007.

RESULTS: In this study, 23 857 incident gout patients (mean age 61.9 years) were included, overall incidence rate was 2.68 (95% CI 2.65, 2.72) per 1000 person-years. The proportion of patients with at least one flare during the follow-up period (mean 3.8 years) was 36.9% (n=8806). A history of ischaemic heart disease [hazard ratio (HR) 1.12 (95% CI 1.06, 1.19)], hypertension [HR 1.15 (95% CI 1.10, 1.20)] and renal failure [HR 1.33 (95% CI 1.20, 1.48)] were independently associated with a higher risk of a first gout flare. Use of allopurinol at initial gout diagnosis was associated with a lower risk [HR 0.80 (95% CI 0.75, 0.85)].

CONCLUSIONS: Gout flares are relatively common among patients with gout. Some of the underlying cardiometabolic comorbid conditions are themselves independent risk factors for flares, which further contribute to the complexity of treatment of gout flares.