Retrospective optimal ratio and sample size calculation for the overall comparison of on-scene times for road traffic collisions compared with other trauma calls, entrapment compared with non-entrapment and prehospital rapid sequence induction (PRSI) compared with non-PRSI
| Comparison overall of missions | Actual ratio | Optimal ratio | Actual sample | Optimal sample |
|---|---|---|---|---|
| RTC, road traffic collision; OTC, other trauma calls. | ||||
| RTCs v OTCs | 1 | 0.59 | 180 | 45 |
| Entrapment vnon-entrapment | 0.19 | 0.5 | 180 | 31 |