[Helicopter-Mobile Medical Teams in The Netherlands: significant differences in deployment frequencies between...

To investigate whether Helicopter-Mobile Medical Teams (H-MMTs or HEMS) are optimally deployed in all emergency dispatch centres.

Descriptive, retrospective.

Initially, we assessed whether data from different ambulance regions could be compared effectively if they were related to the number of inhabitants per region. Data concerning the number of inhabitants, number of deaths caused by trauma, number of traffic accidents with injury, number ofemergency call-outs by ambulance services and H-MMT deployment were collected from several governmental databases for the period 2002-2005. The correlation coefficients between these data and the number of inhabitants were calculated. Subsequently, we determined the number of H-MMT deployments per 100,000 inhabitants per year per emergency dispatch centre. The number of H-MMT dispatches from the 4 H-MMT coordinating dispatch centres was compared to the number of dispatches from the 17 other emergency dispatch centres.

There was a strong correlation between the number of deaths caused by trauma, the number of traffic accidents with injury, emergency call-outs from ambulance services, and the number of inhabitants per region (correlation coefficients: 0.90-0.98). On average there were 2664 H-MMT calls per year. The average number of H-MMT calls per emergency dispatch centre per year was 110 (range: 2-403). The number of H-MMT deployments per 100,000 inhabitants per year was 10.5 (0.9-27.8). Emergency dispatch centres coordinating H-MMTs conducted significantly more H-MMT calls with a lower cancellation rate.

By relating the deployment of H-MMTs with the number of inhabitants per region, a comparison can be made of the deployment frequencies in different emergency dispatch regions. The deployment of H-MMTs proved to differ significantly between emergency dispatch centres.