A total of 204 primary end-point events were observed ( 3.8 events per 100 person-years ; 95 % confidence interval [ CI ] , 3.3 to 4.4 ) , including 68 in patients with a baseline CD4 + count of at least 500 cells per cubic millimeter ( 3.2 events per 100 person-years ; 95 % CI , 2.4 to 4.0 ) .