Wearable cuffless blood pressure monitoring devices: a systematic review and meta-analysis

Sheikh Mohammed Shariful Islam; Clara K Chow; Reza Daryabeygikhotbehsara; Narayan Subedi; Jonathan Rawstorn; Teketo Tegegne; Chandan Karmakar; Muhammad U Siddiqui; Gavin Lambert; Ralph Maddison

doi:10.1093/ehjdh/ztac021

Wearable cuffless blood pressure monitoring devices: a systematic review and meta-analysis

Eur Heart J Digit Health. 2022 May 2;3(2):323-337. doi: 10.1093/ehjdh/ztac021. eCollection 2022 Jun.

Authors

Affiliations

¹ Institute for Physical Activity and Nutrition, Deakin University, Melbourne, Australia.
² Westmead Applied Research Centre, University of Sydney, Sydney, Australia.
³ The George Institute for Global Health, UNSW, Sydney, Australia.
⁴ Department of Cardiology, Westmead Hospital, Sydney, Australia.
⁵ School of IT, Deakin University, Geelong, Australia.
⁶ Marshfield Clinic Health System, Rice Lake, USA.
⁷ George Washington University, Washington, DC, USA.
⁸ Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Vic, Australia.

Abstract

Aims: High blood pressure (BP) is the commonest modifiable cardiovascular risk factor, yet its monitoring remains problematic. Wearable cuffless BP devices offer potential solutions; however, little is known about their validity and utility. We aimed to systematically review the validity, features and clinical use of wearable cuffless BP devices.

Methods and results: We searched MEDLINE, Embase, IEEE Xplore and the Cochrane Database till December 2019 for studies that reported validating cuffless BP devices. We extracted information about study characteristics, device features, validation processes, and clinical applications. Devices were classified according to their functions and features. We defined devices with a mean systolic BP (SBP) and diastolic BP (DBP) biases of <5 mmHg as valid as a consensus. Our definition of validity did not include assessment of device measurement precision, which is assessed by standard deviation of the mean difference-a critical component of ISO protocol validation criteria. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies version 2 tool. A random-effects model meta-analysis was performed to summarise the mean biases for SBP and DBP across studies. Of the 430 studies identified, 16 studies (15 devices, 974 participants) were selected. The majority of devices (81.3%) used photoplethysmography to estimate BP against a reference device; other technologies included tonometry, auscultation and electrocardiogram. In addition to BP and heart rate, some devices also measured night-time BP (n = 5), sleep monitoring (n = 3), oxygen saturation (n = 3), temperature (n = 2) and electrocardiogram (n = 3). Eight devices showed mean biases of <5 mmHg for SBP and DBP compared with a reference device and three devices were commercially available. The meta-analysis showed no statistically significant differences between the wearable and reference devices for SBP (pooled mean difference = 3.42 mmHg, 95% CI: -2.17, 9.01, I² 95.4%) and DBP (pooled mean = 1.16 mmHg, 95% CI: -1.26, 3.58, I² 87.1%).

Conclusion: Several cuffless BP devices are currently available using different technologies, offering the potential for continuous BP monitoring. The variation in standards and validation protocols limited the comparability of findings across studies and the identification of the most accurate device. Challenges such as validation using standard protocols and in real-life settings must be overcome before they can be recommended for uptake into clinical practice.

Keywords: Blood pressure (BP); Cardiovascular disease; Digital health; Hypertension; Non-invasive; Validation.

Publication types

Review