Fast access to the Emergency Medical Communication Center (EMCC) is essential for the population in emergency situation. It is therefore essential that these call centers operate quickly and provide good quality service. However, in recent years, EMCCs have experienced a constant and increasing demand from the population. Thus, maintaining the current organization of emergency medical communication centers raises questions about both the volume of incoming calls to EMCCs and the economic constraints, which make it difficult to manage call peaks, especially in periods of crisis.

The aim of our study is to assess the impact of incoming call distribution virtualization in EMCCs on their service quality.

France is facing political decisions on the evolution of Emergency Medical Communication Center organization to improve population accessibility. Regarding the performance targets requested by the French government (MARCUS report: http://www.urgences113.fr/marcus/Rapport\_MARCUS3.pdf), the virtualization of inbound call distribution could improve EMCC service quality indicators.

The Virtualization is a process that consists of centralizing calls from different territories before distributing them to the centers concerned according to their availability. The objective through this process is to improve the population' access to the EMCC by reducing waits time. And on the other hand, to optimize the activity rate of dispatchers and physicians.

Inclusion Criteria:

• All incoming calls passing through the five Emergency Medical Centers in the Pays de la Loire region (Loire-Atlantique, Maine-et-Loire, Mayenne, Sarthe and Vendée). In each center, an advanced telephone system automatically keeps track of all inbound calls.

Exclusion Criteria:

According to the French national consortium, incoming calls that hung up in less than 10 seconds are considered as dialing errors and are excluded

All Users calling through the five Emergency Medical Centers of the French Pays de la Loire region (5 areas of the region are : Loire-Atlantique, Maine-et-Loire, Mayenne, Sarthe, Vendée).

In each Emergency Medical Center, an advanced telephone system automatically keeps track of all inbound calls.

Average annual number of incoming calls for the 5 Emergency Medical Center of Pays de la Loire region is 1,6 million.