Repeatability, Reproducibility, and Concurrent Validity of a Stethoscope and Health App System for the Quantification of Breath Rate in Healthy Adults: Repeatability and Validity Study

BACKGROUND: Apps for smartphones that can measure the breathing rate easily can be downloaded. OBJECTIVE: The aim of this study was to demonstrate agreement in measuring breath rates between the stethoscope and Breath Counter health app. METHODS: We performed a repeatability study with 56 healthy volunteers. The patient’s demographic data and breathing rates per minute were collected. Breathing rates were measured via two methods: (1) using a stethoscope placed in the upper area of the right lung and (2) a Breath Counter app developed by Vadion on a Samsung Fold smartphone. RESULTS: This study demonstrated high repeatability and validity with respect to the breathing rate parameter of healthy adults using the aforementioned 2 systems. Intrasession repeatability measure using the intraclass correlation coefficient was >0.962, indicating excellent repeatability. Moreover, the intraclass correlation coefficient between methods was 0.793, indicating good repeatability, and coefficients of variation of method errors values were 1.83% with very low values in terms of other repeatability parameters. We found significant correlation coefficients and no systematic differences between the app and stethoscope methods. CONCLUSIONS: The app method may be attractive to individuals who require repeatability in a recreational setting.