Feasibility of conducting a randomized, placebo-controlled study assessing whether omega-3 fatty acids prevent gout flares when starting urate-lowering treatment.

Objective: The aim was to test the feasibility of a randomized controlled trial exploring whether omega-3 fatty acid supplementation limits gout flares during treat-to-target urate-lowering treatment (T2T-ULT). Methods: Adults with at least one gout flare in the past 12 months and serum urate (SU) ≥360 µmol/l were recruited from general practices (primary method) and randomly assigned 1:1 to receive omega-3 fatty acid supplementation (4 g/day) or placebo for 28 weeks. At week 5, participants began T2T-ULT. The primary outcome was drop-out rate. Secondary outcomes were recruitment rate, outcome data completeness, the number, severity and duration of gout flares between weeks 5 and 28, and study drug compliance. Results: Ninety-five per cent of randomized participants (n = 60) completed all study visits. The primary method recruitment rate was 2.2%. Fifty and 42 participants achieved SU < 360 and 300 µmol/l (6 and 5 mg/dl), respectively. The number of gout flares [median (interquartile range): active 1 (0-2) and placebo 1 (0-2)], flare duration [mean (s.d.): active 7.00 (4.52) days and placebo 7.06 (8.14) days] and time to first flare [hazard ratio (95% CI) 0.97 (0.50, 1.86)] were comparable between both arms. Study drug compliance was high and comparable in both arms [median (interquartile range) returned capsule count: active 57 (26-100) and placebo 58 (27-154)]; red blood cell omega-3 fatty acid index increased twofold in the active arm and remained unchanged in the control arm. Conclusion: The study demonstrated feasibility and provided useful metrics for conducting a community-based gout flare prophylaxis trial. Study registration: ISRCTN; https://www.isrctn.com/; ISRCTN79392964.