Exacerbation in cystic fibrosis play an important role in terms of mortality and morbidity. Exacerbation frequencies is relatedto FEV1 decline and mortality. There is a relationship between exacerbation frequency and QoLdeterioration. Moreover exacerbation treatments present health costs burden leading to important physical psychological and social impact. Preventing exacerbation and early detection of these exacerbations may decrease intensity and freqauency of exacerbation leading to increase clinical status and QoLwith a decreased health cost.

Patients actually follow in CRCM track exacerbations when visits out patient clinic and during phone call. If patients did not call or did not present regularly to out patient clinic, exacerbation detection came later and so increasde the burden and therapeutic pressure.

The objective of our study is to identify earlier the potential exacerbations and so decreased the health costs and increased the patient's QoL. Forthis purpose we propose to use modern technologiessuch as smartphone in order to create alert when patients report weekly health satatus. We will compra patients randomize in control group with standart follow-up to patients randomize in the smartphone group.Moreover we will study the compliance and satisfactory degree of the use of this device in the interventional arm.

Exacerbation in cystic fibrosis play an important role in terms of mortality and morbidity. Exacerbation frequencies is relatedto FEV1 decline and mortality. There is a relationship between exacerbation frequency and QoLdeterioration. Moreover exacerbation treatments present health costs burden leading to important physical psychological and social impact. Preventing exacerbation and early detection of these exacerbations may decrease intensity and freqauency of exacerbation leading to increase clinical status and QoLwith a decreased health cost.

Inclusion criteria:

• CF diagnosis
• Patient able to receive phone call
• Patient who use regulary a smartphone
• age from 14 to 25
• Patients with at least 2 exacerbations before the entry.
• Stable patient at V1

Exclusion criteria:

• Patients who are include in an interventional study
• Patient who is not able to read French language
• Patients with psychological disorder