Reliability and validity of an electronic respirometer for measuring respiratory muscle strength in healthy children

Purpose Respiratory muscle strength evaluation is one of the key predictors for respiratory health in children. Commonly used manometers are widely available for assessing the respiratory muscle strength which are lacking in digital storage. This study mainly focusses on measurement of maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) in children through electronic respirometer to find the reliability and validity. Methods A total of 100 healthy children aged 5–16 years were recruited using convenient sampling method. Maximum inspiratory and expiratory pressure were assessed through electronic respirometer. Two trained evaluators assessed the MIP and MEP on separate days and each participant were taken with three trails for each test. The inter- and intra-rater reliability were found out for obtaining content validity index (CVI). Pearson correlation was taken to find out the validity of this instrument. Result The reliability of both MIP and MEP shown an excellent inter-rater reliability (Interclass correlation coefficient (ICC) = 0.98) and intra-rater reliability (ICC = 0.94). The electronic respirometer measurement shown stronger correlation with standard values (r = 0.88 and r = 0.89 for MEP). Conclusion It has been shown that electronic respirometer is a valid and reliable tool for measurement of inspiratory muscle strength and expiratory muscle strength in healthy children. In clinical and research setting, it is suitable and easy to use the electronic respirometer than the traditional devices.