Accepted for/Published in: JMIR Cardio
Date Submitted: Apr 18, 2025
Open Peer Review Period: Apr 18, 2025 - Jun 13, 2025
Date Accepted: Oct 5, 2025
(closed for review but you can still tweet)
Using patient-held devices to measure variations in resting heart rate and step count prior to presentation with an acute illness: the results of an international, multicentre flash mob feasibility study
ABSTRACT
Background:
Many patients experience a gradual decline in health before seeking hospital care, with subtle changes in vital signs such as increased heart rate or decreased mobility. Recognising deviations from baseline vital signs can support clinical decision making, especially admission decisions. Smart devices (i.e. smartphones, smartwatches and activity trackers) track health metrics like heart rate and step count, offering new opportunities to estimate illness severity and tracking deterioration early.
Objective:
To assess the feasibility of using heart rate and step count measurements from smart devices (i.e. smartphones, smartwatches and activity trackers) to enhance the evaluation of patients presenting with acute illness in emergency setting.
Methods:
We conducted an international multicentre prospective observational study using the flashmob study design in 34 hospitals in the Netherlands (n=17), the United Kingdom (n=7), Denmark (n=9) and Switzerland (n=1) in May 2024. Researchers collaborated with patients to complete questionnaires upon acute care (i.e. emergency department, acute medical unit, same day emergency care) visit and extracted physiological data from their smart devices.
Results:
Among patients with an acute care visit (n=1137), 40% had a smart device with health data. These patients tended to be from a higher educational level and in relatively good health. Only half had retrievable heart rate or step count data, resulting in a usable data set for 20% of the total study population. Analysis showed a significant increase in heart rate and a decrease in step count in the days preceding their hospital visit.
Conclusions:
Our study demonstrates the feasibility of using a patient’s own smart device to measure vital signs in the days preceding an acute care visit. Significant changes in heart rate and step count prior to presentation to hospital were demonstrated in a selected group of patients. High-risk patient groups, who might benefit the most from digital health monitoring, are currently underrepresented among device users.
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.