The Reliability and Validity of a Portable Hand-held Spirometer for the Measurement of Various Lung Functions in Healthy Adults

Objective: To assess the reliability and validity of a new handheld spirometer as a potential substitute for traditional pulmonary function testing (PFT) devices. Design: Cross-sectional study. Methods: Thirty healthy adults underwent spirometry using a new handheld spirometer and anMIR spirometer, a standard PFT device. Peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV1), and forced vital capacity (FVC) were measured and analyzed for validity and reliability. Inter-rater reliability and validity were evaluated using 95% limits of agreement (LOA) and intraclass correlation coefficients (ICCs). Statistical analyses, including Bland-Altman plots and ICCs, were used to assess the agreement between the two devices. Results: The new handheld spirometer exhibited good agreement with an ICC [2,1] of 0.762 – 0.956 and 95% LOA of –1.94 – 1.80 compared with the MIR. The test–retest reliability of the handheld spirometer demonstrated a good level of consistency (ICC [2,1] = 0.849 – 0.934). Conclusions: The new handheld spirometer exhibited good test–retest reliability across all measured variables, suggesting its potential as a valid and reliable tool for simultaneous PFT measurements.