Thus , during the initial and long-term follow-up ( median , 84 months ) , 9 patients in the allopurinol group had a renal event compared with 24 patients in the control group ( HR , 0.32 ; 95 % CI , 0.15-0 .69 ; P = 0.004 ; adjusted for age , sex , baseline kidney function , uric acid level , and renin-angiotensin-aldosterone system blockers ) .