Paper | Study design | Source of data | No. of patients | Comparison | Outcomes |
Hannan17 (2005) | Retrospective observational cohort study | New York State Trauma Registry, USA (1996–1998) | 2763 head injured patients (GCS <14) | By ambulance destination:
| Odds of mortality (1) vs (2): 0.67 (0.53 to 0.85) |
Di Russo18 (2005) | Retrospective observational cohort study | National Pediatric Trauma Registry, USA (1994–2002) | 5460 intubated patients (age <20, primary diagnosis ‘injury’) | By site of intubation:
| Mortality stratified by RHISS: higher for (2) vs (3) at all severities |
Stevenson19 (2001) | Simulation model to compare triage strategies | N. Staffordshire RNU Local data, publications and expert opinion | 10 000 simulated head injuries | 11 triage strategies | No superior strategy, but current policy (take to nearest DGH)→delayed intervention |
Patel20 (2005) | Prospective observational cohort study | UK Trauma Audit and Research Network database (1996–2003) | 6921 blunt head injuries admitted to TARN hospitals (any age) | By treatment location
| Odds of mortality (1) vs (2): 2.15 (1.77 to 2.60) |
Poon21 (1991) | Prospective observational cohort study | Single RNU in Hong Kong (1985–1989) | 104 patients requiring surgery for EDH | By transfer:
| Mortality rate: 4% (1) vs 24% (2) |
Härtl22 (2006) | Prospective observational cohort study | Data from 24 trauma centres in New York State, USA (2000–2004) | 1123 head injury patients treated at a trauma centre (GCS <9) | By transfer:
| Odds of mortality (1) vs (2): 1.48 (1.03 to 2.12) |
DGH, district general hospital; EDH, extradural haematoma; GCS, Glasgow Coma Scale; RHISS, relative head injury severity scale; RNU, regional neurosciences unit; TARN, Trauma Audit and Research Network.