Risk of venous thromboembolism with gout flares

Objective: Previous studies reported an increased risk of venous thromboembolism (VTE) in gout, but not whether there was a temporal association between gout flare and VTE. We evaluated whether there was a temporal association between gout flare and VTE. Methods: Electronic primary-care records from the UK's Clinical Practice Research Datalink linked to hospitalization and mortality registers were used. Self-controlled case series analysis adjusted for season and age evaluated the temporal association between gout flare and VTE. The 90 days after primary-care consultation or hospitalization for gout flare was the exposed period. This was divided into three 30-day intervals. The baseline period was up to 2 years before the start of and up to 2 years after the end of exposed period. The association between gout flare and VTE was measured using adjusted incidence rate ratio (aIRR) with 95% confidence interval (95%CI). Results: 314 patients met the inclusion criteria (age ≥18 years, incident gout, without VTE or primary-care anticoagulant prescription before pre-exposure period started) and were included. VTE incidence was significantly higher in the exposed period than in baseline period [aIRR (95%CI) 1.83 (1.30-2.59)]. The aIRR (95%CI) of VTE during the first 30 days after gout flare was 2.31 (1.39-3.82) compared with baseline period. No increase in aIRR (95%CI) were observed in days 31-60 [aIRR (95%CI) 1.49, (0.79-2.81)] and days 61-90 [aIRR (95%CI) 1.67 (0.91-3.06)]. Results were consistent across sensitivity analyses. Conclusion: There was a transient increase in VTE rate within 30 days after primary-care consultation or hospitalization for gout flare.