Single-factor analysis revealed 15 statistically significant factors: length of ICU stay, surgery, number of surgeries, fever, days with fever, COPD, CRP, PCT, urinary WBC count, indwelling central-venous catheter, duration of CVC days, number of indwelling CVC, number of indwelling urinary catheter, indwelling urinary catheter, and number of reintubations (all P < 0.05; Table 1). The gene discussed is CRP; the disease is chronic obstructive pulmonary disease.