[Evaluation of the reliability of 2 portable electronic spirometers]

Two portable electronic spirometers, Vitalograph Compact (C) and Vitalograph Alpha (A), were evaluated for measurement of forced expiratory volume in the first second (FEV1), slow vital capacity (VC), forced vital capacity (FVC) and peak expiratory flow rate (PEF) compared with a high quality Gould 2400 spirometer (G). Ten normal subjects and 10 patients with obstructive lung disease performed spirometry at the same time of day and in randomized order. The results showed a close agreement between G and C or A for FEV1 (r = 0.99 and 0.97 respectively); for VC (r = 0.99 and 0.98 respectively); for FVC (r = 0.99 and 0.97 respectively), and for PEF (r = 0.95 and 0.93 respectively). The results show that these 2 portable spirometers are highly accurate for the parameters measured.