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^®, 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^® 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.