Comparison of Wright scale and European scale peak flow meters with digital spirometer

Introduction: Peak expiratory flow (PEF) monitoring has been in use to measure airflow obstruction in patients with asthma. Most of the peak flow meter uses a traditional Wright scale to record PEF whilst after 2004 Peak flow meters with new European scale have been introduced. This study was done to assess the limits of agreement of PEF values measured with mini Wright's peak flow meter (Wright scale) or with new European scale with digital spirometer. Material and Methods: 582 healthy volunteers between the age group of 18-40 years were recruited for this study. PEF was measured with mini wright's peak flow meter with traditional wright scale and new EU PEF scale. Simultaneously Spirometery of each subject was performed with Sprobank G and FVC, FEV1, FEV1%, PEF were recorded. Results: PEF measured with wrights scale and new European scale both shows high and similar levels of correlation with digital spirometer (r=0.765 and 0.767). Despite a high correlation observed between measured PEF with different instruments, the limits of agreement are not acceptable for either of the scales. Conclusion: The measurement of PEFR with New European scale does not seem to provide any significant advantage over traditional scale.