Clinical Comparison of Peak Flow Meter and Digital Spirometer in Measuring Peak Expiratory Flow Rate

Background: Peak Expiratory Flow Rate (PEFR) is an essential measure of pulmonary function, usually being made with the help of either peak-flow meters or digital spirometers. Differences between ‘the two machines can have an effect on clinical interpretation and respiratory condition management. Aim: Compare the measurements of PEFR taken by a peak flow meter and a digital spirometer in healthy subjects, patients with asthma, and patients with Chronic Obstructive Pulmonary Disease (COPD). Methodology: Retrospective comparative study was carried out in the Department of Physiology, Gouri Devi Institute of Medical Sciences, Durgapur, West Bengal, India. Sixty individuals were randomized into three groups of 20 each, namely, Group A (normal, healthy individuals), Group B (asthmatics), and Group C (patients with COPD). Both peak flow meter and electronic spirometer were employed for measuring PEFR, of which the best of three attempts was taken for both instruments. Statistical analysis included paired t-tests and ANOVA with adjustment for Bonferroni correction. Results: In all groups, the digital spirometer showed consistently higher PEFR measurements than the peak flow meter (p < 0.001). The mean difference was 12 L/min in the healthy, 18 L/min in the asthmatic, and 22 L/min in the COPD groups. Aging-induced decline in PEFR was noted, but the digital spirometer had higher readings in all age groups. Conclusion: Peak Expiratory Flow Rate measurements taken with peak flow meters and digital spirometers are not equal, as they have considerable variation. Both are useful tools, but the digital spirometer is more accurate, particularly in those with poor lung function.