The long-term stability of portable spirometers used in a multinational study of the prevalence of chronic obstructive pulmonary disease.
BACKGROUND
We report the performance of an ultrasound-based portable spirometer (EasyOne) used in a population-based survey of the prevalence of chronic obstructive pulmonary disease, conducted in 5 Latin American cities: São Paulo, Brazil; México City, México; Montevideo, Uruguay; Santiago, Chile; and Caracas, Venezuela (the Latin American COPD Prevalence Study [PLATINO]).


METHODS
During the survey period (which ranged from 3 months to 6 months in the various locations) we collected daily calibration data from the 70 EasyOne spirometers used in the 5 survey cities. The calibrations were conducted with a 3-L syringe, and the calibration data were stored in the spirometer's database.


RESULTS
Ninety-seven percent of the calibration volumes were within +/- 64 mL (2.1%) of the 3-L calibration signal. Excluding data from the first city studied (São Paulo), where one calibration syringe had to be replaced, 98% of the calibration checks were within +/- 50 mL (1.7%). The measured volume was affected only minimally by the syringe's peak flow or emptying time.


CONCLUSIONS
In these 70 EasyOne spirometers neither calibration nor linearity changed during the study. Such calibration stability is a valuable feature in spirometry surveys and in the clinical setting.
Pérez-Padilla
Rogelio
R
Instituto Nacional de Enfermedades Respiratorias, Tlalpan 4502, Distrito Federal, Ciudad de México, México 14080. perezpad@servidor.unam.mx
Vázquez-García
Juan Carlos
JC
Márquez
María Nelly
MN
Jardim
José Roberto B
JR
Pertuzé
Julio
J
Lisboa
Carmen
C
Muiño
Adriana
A
López
María Victorina
MV
Tálamo
Carlos
C
de Oca
María Montes
MM
Valdivia
Gonzalo
G
Menezes
Ana Maria B
AM
D001938:Brazil / Q000453:epidemiology; D002138:Calibration; D002677:Chile / Q000453:epidemiology; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D013147:Spirometry / Q000295:instrumentation*; D014583:Uruguay / Q000453:epidemiology; D014687:Venezuela / Q000453:epidemiology