Table 2.
Pooled estimated for patients’ characteristics in unmatched studies
| Characteristic | No. of studies | Total sample size | Pooled estimate | ||
|---|---|---|---|---|---|
| Outpatient/inpatient | Outpatient | Inpatient | P value | ||
| Male sex (%) | 81–3; 14; 20; 21; 26; 27 | 6901/187,536 | 50.5% | 39% | < 0.001* |
| ASA class ≥ III (%) | 314; 20; 21 | 599/13,162 | 35.2% | 48.4% | < 0.001* |
| Diabetes | 81–3; 14; 20; 21; 26; 27 | 6901/187,536 | 14.2% | 19.3% | < 0.001* |
| Cardiopulmonary comorbidity | 23; 27 | 999/38,154 | 11.5% | 20.2% | < 0.001* |
| Cardiovascular comorbidity | 32; 20; 26 | 3933/125,998 | 19.4% | 24.4% | < 0.001* |
| Pulmonary comorbidity | 42; 20; 21; 26 | 4106/133,022 | 18.9% | 18.8% | 0.87 |
| Hypertension | 221; 26 | 208/7070 | 51.4% | 67.6% | < 0.001* |
| Mean BMI† | 43; 14; 26 | 297/459 | 29.9 | 31.42 | – |
| Obesity | 42; 20; 21; 27 | 5049/171,090 | 16.8% | 15.7% | 0.034* |
| Smoker | 62; 3; 14; 20; 21; 26 | 4368/133,435 | 8.1% | 5% | < 0.001* |
ASA American Society of Anaesthesiologists; BMI body mass index. (*) Asterisk denotes a statistically significant comparison