Comparability of portable and desktop spirometry: a randomized, parallel assignment, open-label clinical trial

Introduction: Portable spirometers are often perceived as inaccurate. We aimed to evaluate the performance of AioCare (R), a new portable spirometer, by comparing it with a reference desktop spirometer. Materials and methods: Sixty-two patients diagnosed with asthma or chronic obstructive pulmonary disease performed spirometry examinations on a portable and the reference spirometer. The patients were randomized to two groups with different order, in which the spirometers were used. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF) and FEV1/FVC rate were compared. Results: The study revealed a high correlation in FEV1, FVC, FEV1/FVC and PEF between portable and reference spirometers. The mean differences between measurements obtained from the AioCare (R) and reference spirometer were: 0.0079 liter for FEV1 (p = 0.61), 0.05 liter for FVC (p = 0.14), 5.1 liter/min for PEF (p = 0.28) and -0.0034 for FEV1/FVC rate (p = 0.54). Pearson correlation coefficient analysis showed high association of FEV1 (R = 0.994; 95% CI: 0.990-0.997; p < 0.001), FVC (R = 0.984; 95% CI: 0.974-0.990; p < 0.001), PEF (R = 0.965; 95% CI: 0.942-0.979; p < 0.001), and FEV1/FVC (R = 0.954; 95% CI: 0.924-0.972; p < 0.001) readings from both spirometers. Conclusions: Our results indicate that the portable spirometer produces largely similar readings to those obtained by a stationary spirometer in patients with chronic lung diseases, and therefore it may serve as a complementary tool in daily, remote management of patients with lung diseases.