Eur J Emerg Med. 2015 Dec;22(6):384-90. 
van Schuppen H, Bierens J.

Abstract
OBJECTIVE:
In our previous study, we identified the similarities and differences in competencies of ambulance nurses and helicopter emergency medical service (HEMS) physicians in the Netherlands. This ensuing study aims to quantify the frequency with which the additional therapeutic competencies of the HEMS physician are utilized and to determine whether this is the main reason for usefulness as perceived by ambulance nurses and HEMS physicians.

MATERIALS AND METHODS:
A prospective observational study was carried out over a 2-month period, with one HEMS station covering six ambulance regions. Provider registration was recorded, supplemented by interviews of ambulance nurses and HEMS physicians. Competencies were categorized depending on whether the competency was specific for the nurse or physician, mutual or mutual with a qualitative difference.

RESULTS:
A total of 225 HEMS dispatches resulted in 117 cases with HEMS on-scene in the study region and 78 patients were included. In 35 (45%) patients, the HEMS physician provided additional treatment: in 19 (24%) patients, a physician-specific therapeutic competency, in nine (12%) patients, a mutual competency with a qualitative difference and in seven (9%) patients, both categories. The presence of the HEMS physician was considered more useful by both ambulance nurses (89 vs. 60%) and HEMS physicians (97 vs. 81%) when additional treatment was provided by the HEMS physician.

CONCLUSION:
HEMS physicians provide additional treatment in 45% of patients. The additional treatment increases the perceived usefulness of the HEMS physician. The presence of the HEMS physician was also considered useful when the physician did not provide any additional treatment, possibly because of diagnostic competence and clinical decision-making.