Usefulness of a mobile phone application for respiratory rate measurement in adult patients

Aims: Respiratory rate measurement is one of the core nursing skills for early detection of deterioration of a patient's condition. Nevertheless, it is sometimes bothersome to visually measure respiratory rate over 1 min. Respiratory rate measurement using a mobile phone application “RRate” has been reported to be accurate and completed in a short time. However, it has only been investigated in children. The aim of this study was to validate the “RRate” compared with the 1-min method in adult patients. Methods: This was a cross-sectional study in the setting of a nursing school. Videos of the movement of the thorax during respiration of adult patients were made. Nursing students watched these videos and measured respiratory rate with each method. Bland–Altman analysis was used to calculate bias and limits of agreement. The times taken for the measurements were compared using a t test. Results: A total of 59 nursing students participated. When compared to the reference measurement, the one measured using “RRate” and the one measured over 1 min showed a bias of 0.40 breaths per minute and 0.65 breaths per minute, limits of agreement of −2.86 to 3.67 breaths per minute and −2.11 to 3.41 breaths per minute, respectively. The mean measurement time for “RRate” was 22.8 s (95% CI 13.9–36.6), which was significantly shorter than the 65.8 s (95% CI 61.0–73.2) for the measurement over 1 min (p <.001). Conclusions: Respiratory rate can be measured accurately in a shorter time using a mobile phone application in adult patients.