Factors with significant differences between the two groups included body temperature, C-reactive protein (CRP), creatinine, albumin, length of hospital stay, source of patients, previous infection, renal replacement therapy, immunosuppressive agents, non-invasive ventilator, gastroscope, enema, arterial catheter, carbapenems, 3/4 generation cephalosporins, and tigecycline (all P < 0.05) (Supplementary Table 2). This evidence concerns the gene CRP and infection.