We randomly assigned 781 patients with previously untreated CLL and a score higher than 6 on the Cumulative Illness Rating Scale ( CIRS ) ( range , 0 to 56 , with higher scores indicating worse health status ) or an estimated creatinine clearance of 30 to 69 ml per minute to receive chlorambucil , obinutuzumab plus chlorambucil , or rituximab plus chlorambucil .