PPIB and infection: Age > 60 years (p = 0.009), CKD (p = 0.015), CRD (p < 0.001), blood transfusion during admission (p = 0.003), HAIs (p = 0.021), 90-day previous exposure to cephalosporins (p = 0.007),β-lactam/β-lactamase (p < 0.001), as well as polymicrobial infection (p = 0.024), were collectively significant contributors to 28-day mortality.