Cancellations of (helicopter-transported) mobile medical team dispatches in the Netherlands.

"Retrospective, comparative observational studies are inherently less accurate than a properly setup prospective study. We tried to minimize selection bias by performing a consecutive case review. Missing data however remains a clear obstacle in performing adequate research to trauma systems []. Also, several major obstacles to the development of quality EMS research exist. Funding is woefully inadequate and integrated information systems are needed to link data on patient care with information on outcome []. The properties of emergency medicine and trauma patients itself make it hard to apply the optimal scientific study design in this population. In trauma care, prospective (randomized) research in the prehospital is even more difficult. Although prehospital randomisation in trauma research is complex, it seems to be feasible. Therefore, we suggest a large prospective study were seriously injured patients are included, with the aim to trace and analyse the causes and reduce the rate of over- and undertriage."