Comparison of cholecystitis grades on LOS, conversion to open, age, SIRS at admission, cost of hospitalization, and LOO
| Grade | N | LOS (days) | Conversion to open | Age | SIRS at admission | Cost (US$) | LOO (h) |
| 1 | 22 | 2.0±0.4 | 1 (4%) | 39±3 | 4 (18%) | 4980±1172 | 1.3±0.2 |
| 2 | 539 | 2.4±0.1 | 33 (6%) | 40±1 | 64 (12%) | 4206±86 | 1.7±0.0 |
| 3 | 108 | 4.4±0.3 | 19 (18%) | 52±2 | 30 (28%) | 6057±371 | 2.0±0.1 |
| 4 | 8 | 7.7±1.0 | 4 (50%) | 62±6 | 5 (63%) | 10 078±1285 | 2.3±0.4 |
| P value | – | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 |
LOO, length of operation; LOS, length of stay;SIRS, systemic inflammatory response syndrome.