Multivitamins plus selenium in a single supplement , vs placebo , also reduced the risk of secondary events of combined outcomes for disease progression ( CD4 cell count 250/L , AIDS-defining conditions , or AIDS-related death , whichever occurred earlier [ adjusted HR , 0.56 ; 95 % CI , 0.33-0 .95 ; P = .03 ; AER , 6.48 / 100 person-years ; censoring rate , 0.90 ; 23 events ] ) .