Based on clinical and statistical reasons (S1 Table), we chose confounding factors including sex, age, obesity, diabetes, chronic renal insufficiency, heart failure, asthma, immunosuppression, platelets, C-reactive protein, procalcitonin, alanine aminotransferase, aspartate aminotransferase, lung damage on computed tomography, sequential organ failure assessment score, tocilizumab, renal replacement therapy, sepsis, septic shock, acute kidney failure, pneumonia associated with IMV, plateau pressure 24 h after IMV, and driving pressure 24 h after IMV. Here, CRP is linked to chronic kidney disease.