Physician presence on a helicopter emergency medical service: necessary or desirable?

Helicopter emergency medical services may be served by a variety of medical and paramedical crew mixes. Analysis of 395 flights performed by Metro Life Flight in Cleveland, OH indicates that a physician is necessary 25% of the time, is not necessary 39.7% of the time, and may be necessary 34.7% of the time. The patients in the latter group could only be analyzed retrospectively and were of sufficient severity that the possible benefit of the physician was real but unpredictable. Physician presence was necessary for judgement, skill, or both.