| Usage of antibiotics, (%) | χ2 | pvalue | |
---|---|---|---|---|
 | PCT group | Control group |  |  |
Mild | 16/47 (34.0) | 37/50 (74.0) | 15.61 | <0.01 |
Moderate | 21/54 (38.9) | 36/52 (69.2) | 9.81 | <0.01 |
Severe | 13/17 (76.5) | 14/17 (82.4) | 0.18 | = 0.671 |
Critical | 9/10 (90.0) | 8/8 (100.0) | 0.85 | = 0.357 |
Total | 59/128 (46.1) | 95/127 (74.8) | 21.97 | <0.01 |