ALB and infection: As in the analysis of 28-day mortality, group 4 also exhibited a significantly higher 90-day mortality risk even after adjusting for age, sex, SOFA score, CCI, RRT, serum albumin, Hb, lactate, CRP, and infection site (HR, 11.66; 95% CI, 2.57 to 52.97; P = 0.001 in Model 1, HR, 13.74; 95% CI, 2.95 to 64.10; P = 0.001 in Model 2).