[Quality control of spirographic examinations in a health center]

A quality control of spirographic examinations in a health centre was carried out by repeating, after a fortnight's interval, measures of vital capacity (CV) and FEV1 (VEMS) in 629 subject of both sexes, aged 18 to 62. Water spirometers were used and their cylinders were regularly calibrated. The first series of spirographic measurements were made during a routine health check (which included other examinations) by 7 technicians who usually do the work, while the second series of measurements was made of fortnight later by the most experienced three. The overall mean values show a significant difference for vital capacity between the first and second measurement; this difference was so for young male subjects (less than 30 years). The scatter was greater for subjects over 50 years of age. The varied results observed for the same subjects obtained by two different technicians, or the same technician, underlines the fact that the scatter of the results depends largely on the technician even though spirographic tests are classically considered easy to perform.