Patient factors | Comorbidities | Urgency | Planned |
Age | Emergent |
Severity and nature of illness | |
Health systems factors | Prehospital transport | Surgical approach | Open |
Delay to presentation | | Minimally invasive |
Appropriate centre for condition | Intrinsic procedure risk | By specialty |
| By procedure |
| By complexity score |
| Surgeon skill | Specialist versus non-specialist surgeon |
| Surgeon versus non-surgeon physician |
| Physician versus non-physician surgeon |
| Trainee versus fully-trained surgeon |
| Inter-surgeon variation |
| Anaesthetic modality | General, regional, local |
| Anaesthetist skill | Specialist versus non-specialist anaesthetist |
| Anaesthetist versus non-anaesthetist physician |
| Physician versus non-physician provider |
| Trainee versus fully-trained anaesthetist |
| Inter-anaesthetist variation |