Cost-Effectiveness of Low-Dose Colchicine Prophylaxis When Starting Allopurinol Using the "Start-Low Go-Slow" Approach for Gout: Evidence From a Noninferiority Randomized Double-Blind Placebo-Controlled Trial.

Abstract

The aim of this study was to investigate the cost-effectiveness of low-dose colchicine prophylaxis for preventing gout flares when starting allopurinol using the "start-low go-slow" approach. Participants with gout, fulfilling the American College of Rheumatology recommendations for starting urate-lowering therapy and with serum urate ≥0.36 mmol/L (6 mg/dL), were randomly allocated (1:1) to either colchicine (0.5 mg daily) or placebo for six months with a further six-month follow-up. All participants received allopurinol, with monthly increase in dose to achieve target urate <0.36 mmol/L. The primary outcomes were incremental cost-effectiveness at the 6-month and 1-year follow-up from the health system perspective, measured by incremental net monetary benefit (INMB) at a willingness-to-pay threshold equivalent to gross domestic product per capita. Two hundred participants were randomized to either colchicine (n = 100) or placebo (n = 100). Mean costs were higher in the colchicine group over both six months and one year (adjusted mean difference $1,848 [95% confidence interval (CI) -$321 to $4,017] and $2,282 [95% CI -$173 to $4,737], respectively). Quality-adjusted life years were slightly higher in the colchicine group over six months (adjusted mean difference 0.008 [95% CI -0.020 to 0.035]) but lower over one year (-0.015 [95% CI -0.039 to 0.010]). Treatment with colchicine was not found to be cost-effective at either 6 months or 12 months (INMB -$1,373 [95% CI -$4,287 to $1,542] and -$3,191 [95% CI -$6,274 to -$107], probability of cost-effectiveness 17.7% and 1.5%, respectively). Similar results were obtained from a societal perspective. Six months of low-dose colchicine prophylaxis when starting allopurinol using the "start-low go-slow" approach is unlikely to be cost-effective over 12 months.