According to surveys, 13% to 20% of the Service Médical d'Urgence (SAMU) centre 15 (French 911) calls concern elderly patients above 75 years of age. For these patients, the clinical pathway should be decided on the basis of the symptomatology described during the call, but also with the gathering of specific data such as medical social and psychological evaluation. These items allow the regulating doctor to assess comorbidity, on-going treatment, psycho-cognitive status, previous hospitalisations, social situation, and patient expectations and needs.

However, data collected in order to assess the situation on the phone and take the orientation decision are mainly limited to the severity of clinical symptoms. Medical, psychological and social aspects are rarely gathered, for several reasons :

• Phone call shortness : emergency calls should be treated quickly
• Regulating doctors are not trained to take in account the specificities or geriatric patients in their decision making. Besides, they are not informed about alternatives to the hospital emergency department, such as "geriatric channel" system.

An observational study was performed in 2012 on 692 calls about elderly patients referred to the SAMU centre 15 during 7 days : 63% of these patients were transferred to an emergency department. Regardless of severe cases "hospital regulation", 55% of the least serious cases ("liberal regulation") were transferred to an emergency department.

Regulation is inadequate to elderly patients for whom 1) the situation assessment and the appropriate decision making require specific items that are not known by regulating doctors, 2) the medical care and the clinical pathway could be improved by the knowledge of on-field "geriatric channel", 3) the emergency department care is particularly long, 4) and could be pernicious to younger patients.

1920 patients will be recruited between January 2016 and August 2017, including a 6 months wash-out in order to train regulating doctors. This training will include geriatric patient's specificities, and geriatric channels. A 12% difference between the 2 groups (before and after the training) is expected, considering a 80% statistical power. The design is a time series experiment.

Inclusion Criteria:

• Patient above 75 years olds
• Patient calling for a liberal regulation
• Patient calling between 8 a.m. and 6 p.m. from monday to friday

Exclusion Criteria:

• Patient calling for vital emergency (hospital regulation)
• Patient calling for inter-hospital transport

Elderly patients calling SAMU