Can Caregivers Reliably Assess Their Child's Heart Rate and Respiration Rate Using Smartphone or Smartwatch Applications?

Abstract

Objective: Caregiver monitoring of heart rate (HR) and respiration rate (RR) with smartphone or smartwatch applications (apps) may improve the quality of pediatric telephone triage or virtual visits and help determine which patients require in-person evaluation. Our objective was to compare HR and RR measured by caregivers with iPhone and Apple Watch apps to simultaneous measurements by nurses in the pediatric emergency department (PED).

Methods: Patients under 18 years were prospectively recruited from a PED at an academic children's hospital between January 5 and June 30, 2023. Caregivers and nurses measured HR and RR simultaneously. Nurses used pulse oximeters or cardiorespiratory monitors for assessment of HR and visual assessment of chest rise for RR. Caregivers measured RR on an iPhone app and HR on both iPhone and Apple Watch apps. Reproducibility was assessed using Bland-Altman analyses and summarized using the Kappa agreement. We surveyed caregivers on their level of comfort with the apps before and after use.

Results: We recruited 213 patients with a median [interquartile range (IQR)] age of 7 (4 to 13) years. For the measurement of RR, no bias was evident, but the limits of agreement (LOA) were wide (between -23 and +24 breaths/minute). For HR measurement by iPhone, caregivers reported consistently lower values than nurses (bias: -22 beats/minute), and LOA was wide (-75 to +32 beats/minute). HR measurement by Apple Watch showed no evidence of bias, and the LOA was acceptable (-5 to +5 beats/minute).

Conclusions: When compared with nurse-assessed vital signs, our study showed poor performance for caregiver-measured vital signs on iPhone apps in children presenting to the PED. However, the Apple Watch did reliably assess HR, and caregivers rated it most highly. The next steps include testing the performance of these devices in the home setting.