F2 and pneumonia: This conclusion remained consistent even after adjusting for confounding factors including hypertension; acute renal failure, pneumonia, sepsis, PLR, white blood cell count, serum sodium, blood glucose, prothrombin time, serum creatinine, serum calcium, and mechanical ventilation (Model 3, OR = 1.12, 95% CI: 1.04–1.19, P < 0.001).