Fig. 2

Meta-regression of dose of allopurinol* versus log odds ratio of heart failure (a)^a, total cardiovascular events (b)^b, and serious cardiovascular events (c)^c. * One oxypurinol study [19] contributing with events was excluded from metaregression due to the absence of direct comparisons of serum oxypurinol levels between oral preparations of allopurinol and oxypurinol (produced by Cardiome Pharma Corporation, Vancouver, British Columbia, Canada) used continuously in daily doses. ^aMeta-regression coefficient = 0.004, 95% confidence interval: 0.001 to 0.008, P = 0.008. ^b0.002, 0.001 to 0.004, P = 0.006. ^c 0.002, 0.000 to 0.003, P = 0.039