The comorbidity component was scored as 0 if no comorbidities were present; 1 if there were mild comorbidities present and major comorbid conditions (MCCs) were absent (such as New York Heart Association Class III or IV congestive heart failure, severe coronary artery disease, acquired immunodeficiency syndrome, moderate- to-severe chronic obstructive pulmonary disease, and metastatic malignancies); 2 if moderate comorbidities were present, including one MCC; and 3 if multiple severe comorbidities were present, including two or more MCCs. Subjective global assessments (SGAs) were performed by an experienced physician according to conventional SGA guidelines.