Respiratory Rate Measurement Using Mobile Applications in Healthcare Settings: A Scoping Review

Respiratory rate (RR) is a strong indicator of clinical trajectory and forms the basis of patient care and assessment. However, clinicians often face barriers to easily obtaining a RR without inefficient methods or costly technology. To remedy this, several phone applications have emerged where clinicians can tap out each breath to calculate a RR. We aimed to map the available evidence for tap-per-breath applications used in healthcare settings. We searched for articles using multiple databases, including primary research articles that evaluated tap-per-breath apps in healthcare settings. 14 articles were selected for this review, mostly cross-sectional and hospital based. Most applications reported high usability and efficiency, although results of accuracy were mixed across the included literature. Median-based apps were more often an accurate measure of RR, however more research is required. Articles were commonly limited in generalisability due to poorly defined reference standards, small sample sizes, or using retrospective video recordings for patient assessment. Studies showed favourable usability and efficiency across the literature, with median-based apps demonstrating greater consistency and accuracy of RR measurements. Though the scope of this review and limited evidence restrict any far-reaching clinical implications until further evidence emerges.