Finally, whether the IR indices would further increase the predictive ability of the basic model (including age, AF, Diabetes, CKD, Hypertension, Respiratory failure, ALT, AST, RBC, CK, creatinine, HbA1c, Hb, NT-proBNP, potassium, sodium, BUN, WBC, ACEI/ARB, Antiplatelet drugs, β-receptor). Here, NPPB is linked to respiratory failure.