The investigators aim to demonstrate that spirometry performed "on line" with a technician in a remote place from the patient has the same efficacy as the one performed personally. As a previous study the investigators analyzed the inter-observer agreement between two pulmonary function technicians from both centers taking part in the study: San Pedro de Alcántara Hospital (Cáceres) and Carlos III hospital (Madrid). The main study will be broad (226 patients derivates from primary care to pneumology consultation), prospective, aleatorized, crossed, blind and controlled. The patients will be aleatorized in two groups: 1) personal spirometry: performed in a conventional way; 2) telematic spirometry: performed remotely "on line". The same pulmonary function technician, who will carry out the spirometries personally, will be located in a nearly room. The technician will control the computer office and the spirometer software in the patients's room with another computer. By means of teleconference, the technician will indicate the patient to start the maneuver. After 20 minutes from the end of the first spirometry, the patients will complete the protocol of the following group. The mean values of FVC, FEV1 and FEV1/FVC, the mean time of spirometry performance, the mean number of spirometric maneuvers performed, are compared between both groups by t proof for paired data. The comparison of the percentage of proofs with non acceptability or reproducibility criteria will be made by X2 test. The analysis will be made blindly. The inter-observer and intra-observer agreement will be evaluated by analysis of intraclass correlation for FVC and FEV1 values.

Inclusion Criteria:

• Age between 14 and 70 years.
• Patients referred for pulmonary consultation from primary care center.

Exclusion Criteria:

• Psychophysical incapacity to performed spirometry.
• Informed consent not obtained.