Accepted for/Published in: JMIR Research Protocols
Date Submitted: Sep 25, 2025
Open Peer Review Period: Sep 25, 2025 - Nov 20, 2025
Date Accepted: Dec 5, 2025
(closed for review but you can still tweet)
Association and Agreement of Contact-Based Smartphone Photoplethysmography (PPG) Compared with Electrocardiography (ECG): A Protocol for a Systematic Review and Meta-Analysis
ABSTRACT
Background:
Mobile health (mHealth), leveraging mobile devices for health measurement and promotion, is rapidly growing. Smartphone cameras can perform photoplethysmography (PPG) to estimate pulse rate (PR-PPG) and other features of the cardiac cycle. However, establishing the validity of PR-PPG is essential before it can be adopted for healthcare applications. There is a pervasive belief that PR-PPG is analogous to heart rate derived using electrocardiogram (HR-ECG), and we will conduct a systematic review and meta-analysis to support or challenge this supposition.
Objective:
To synthesise quantitative evidence on the validity of PPG derived from mobile devices (i.e. smartphones) for the assessment of compared to the gold standard ECG assessment of HR.
Methods:
Inclusion criteria: This review will include studies that report the association and agreement between resting HR and PR from PPG utilizing contact-based smartphone devices versus ECG as the gold standard. Studies will be excluded if they (a) do not use PPG utilizing contact-based smartphone devices (b) compare PPG to another collection method other than ECG, or (c) are review articles or case studies.
Methods:
A comprehensive literature search will be performed on CINAHL Ultimate, MEDLINE, ScienceDirect, and Scopus using a predefined search strategy. All retrieved citations will be imported into Rayyan for screening and data management. A minimum of two independent reviewers will conduct the title and abstract screening, followed by two independent reviewers who will perform full-text screening and data extraction. All stages will be guided by predefined inclusion and exclusion criteria, which will be pilot tested to ensure consistency and reliability. Any discrepancies will be resolved through discussion with a third reviewer or during a research team meeting. Intra-rater reliability will be quantified at the title and abstract stage, and the full-text review stage using Cohen’s Kappa. To ensure clarity and consistency in the presentation of study characteristics and findings, both narrative synthesis and tabular formats will be employed.
Results:
Exact numbers are not accessible at this time, as the review is hypothetical and has not yet been conducted. In order to inform clinical procedures and future studies, the results will contain data on PR-PPG and HR-ECG association (correlations) and agreement (Bland-Altmans), sampling devices, and operating systems.
Conclusions:
This review will provide a comprehensive understanding of the association and agreement between PR-PPG and HR-ECG. The findings may guide clinical practice and inform future research on remote assessment of resting heart rate/pulse rate. Clinical Trial: https://doi.org/10.17605/OSF.IO/83V7A
Citation
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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.