Search tips
Search criteria 


Logo of emermedjEmergency Medical JournalVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
Emerg Med J. 2007 July; 24(7): 521.
PMCID: PMC2658422

Doctors and prehospital on‐scene times: effect is still debatable

The article by Dissmann and Le Clerc1 is a welcome addition to the prehospital literature. However, it is important to remind readers that the observation that doctors do not prolong prehospital on‐scene times within their system is simply that: an observation.

All observational studies are influenced by bias, confounding and the play of chance, and in this study there were a number of confounding variables that could have significantly influenced scene times. These include severity of injury, degree of entrapment, resources at scene, interventions before arrival of the helicopter, and the training and experience of the helicopter crew. Without robust case mix adjustment, the true effect of the presence of a doctor on the “on‐scene time” cannot be properly established. The validity of the conclusion is therefore in doubt.

There is also the possibility of bias regarding the types of calls that the doctor and the paramedic teams attended. From the data presented, it is not possible to say that the casualties they attended were comparable. Furthermore, most of the doctor‐attended casualties seem to have required little or no intervention in addition to that provided by paramedics, so are unlikely to have remained on scene for long. With no information regarding how the outcome measure (on‐scene time) was derived or validated, it is possible that significant bias was again introduced, especially if these times were accepted only from written report forms.

In summary, the study explores a clinically relevant area of prehospital care especially since reduced on‐scene times influence the outcome for patients.2 However, whether doctor‐delivered advanced life support in the prehospital phase influences on‐scene time is still debatable.3,4,5,6 Of course, the ultimate measure of the effectiveness of any prehospital critical care and retrieval system must be the outcome for patients. We need to know whether prognosis is affected by the presence of a prehospital critical care team (doctor or non‐doctor based) and, in that context, the influence of prehospital time. Dissmann and Le Clerc have opened the debate: let us now develop collaborative research proposals to answer these questions.


Competing interests: None declared.


1. Dissmann P D, Le Clerc S. The experience of Teesside helicopter emergency services: doctors do not prolong prehospital on‐scene times. Emerg Med J 2007. 2459–62.62 [PMC free article] [PubMed]
2. Feero S, Hedges J R, Simmons E. et al Does out‐of‐hospital time affect trauma survival? Am J Emerg Med 1995. 13133–135.135 [PubMed]
3. Sampalis J S, Lavoie A, Salas M. et al Determinants of on‐scene time in injured patients treated by physicians at the site. Prehospital Disaster Med 1994. 9178–188.188 [PubMed]
4. Garner A, Rashford S, Lee A. et al Addition of physicians to paramedic helicopter services decreases blunt trauma mortality. Aust NZ J Surg 1999. 69679–701.701 [PubMed]
5. Iirola T T, Laaksonen M I, Vahlberg T J. et al Effect of physician‐staffed helicopter emergency medical service on blunt trauma patient survival and prehospital care. Eur J Emerg Med 2006. 13335–339.339 [PubMed]
6. Sampalis J S, Lavoie A, Williams J I. et al Impact of on‐site care, prehospital time, and level of in‐hospital care on survival in severely injured patients. J Trauma 1993. 34252–261.261 [PubMed]

Articles from Emergency Medicine Journal : EMJ are provided here courtesy of BMJ Publishing Group