A Study of the Acceptability and Performance of Wearables for Atrial Fibrillation Screening in Older Adults

SAFER Wearables Study: A Study of the Acceptability and Performance of Wearables for Atrial Fibrillation Screening in Older Adults

--- Background and study aim

Atrial fibrillation (AF) is an irregular heart rhythm which causes a five-fold increase in the risk of stroke. Approximately one in ten people aged over 70 have AF. If AF is recognised then the risk of stroke can be reduced by taking tablets regularly. AF can be difficult to recognise as it can occur without symptoms and only intermittently. Consequently, AF is not recognised in many people, meaning they live with an increased risk of stroke. Therefore, it is important to find ways to identify AF more reliably.

Recently, wearable devices have been developed which could be useful for identifying AF. Several devices can monitor heart activity in daily life, including wristbands, smart watches and chest patch monitors. The aim of this study is to assess the acceptability and performance of wearables for use in AF screening in older adults.

The primary objective is to determine the feasibility of measuring inter-beat-intervals using a wristband. The secondary objectives are:

(i) to determine the acceptability of wearables; (ii) to determine the acceptability of the screening approach; (iii) to assess the performance of wearables for acquiring signals; (iv) to assess the performance of signal processing algorithms; and (v) to assess the performance of wearables for AF screening.

--- Who can participate?

Selected people who have previously participated in the SAFER Programme can participate in this study. The Investigators will invite previous SAFER Programme participants to also participate in this study, aiming to enrol 65 without AF, and 65 with AF.

--- What does the study involve?

Participants will be asked to wear three devices for seven days: Two wristbands (like watches), and one chest patch (like a plaster). These devices will collect measurements of their heart's activity. The Investigators will also ask participants to tell them how they found wearing the devices by completing a questionnaire. The Investigators will compare how participants found wearing each device, and how accurately each device identifies AF.

--- What are the possible benefits and risks of participating?

There will be no direct benefit to participants, although this research is intended to benefit future patients like them. Some participants may experience irritation or redness whilst wearing a chest patch - participants will be advised that if this occurs then they should remove it straightaway.

Study Overview

• Status: Active, not recruiting
• Conditions: Atrial Fibrillation; Paroxysmal Atrial Fibrillation
• Intervention / Treatment: Device: Electrocardiogram monitoring; Device: Electrocardiogram recording; Device: Photoplethysmogram monitoring; Other: Feedback questionnaire

Detailed Description

--- Where is the study run from?

The University of Cambridge.

--- Study procedures

Participants will be asked to:

1. Consent: Participants will be asked to confirm their consent to take part by posting the enclosed consent form to the Investigators in a prepaid envelope.
2. Device delivery: The Investigators will send participants the devices, a detailed instruction leaflet, and a questionnaire.
3. Training: The Investigators will explain to participants how to wear and use the devices over the telephone, referring to the instruction leaflet.
4. Wear the devices: Participants will be asked to wear the devices for seven days, going about their daily life as normal. The devices are waterproof. If a participant has chest hair then they will need to shave a small area for the chest-patch to stick to. The Investigators will ask participants to use the watch four times each day to record heart activity for 30 seconds. Participants will be asked to plug in a small hub which will send information from the devices. The Investigators will telephone participants during the study to check for any problems.
5. Questionnaire: Participants will be asked to complete a questionnaire on the devices after wearing them.
6. Return devices: At the end, the Investigators will telephone participants and arrange a courier to pick up the devices and questionnaire from their home (which the Investigators will arrange and pay for).

Participants will be given an instruction leaflet with further details of each step.

• Study Type: Observational
• Enrollment (Estimated): 130

Contacts and Locations

Study Locations

• United Kingdom
  • Cambridge, United Kingdom
    • University of Cambridge

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Potential participants for the study will be identified from amongst previous participants of the SAFER Programme (ISRCTN 16939438 and ISRCTN 72104369).

Description

Inclusion Criteria:

• AF screening successfully completed during the SAFER Programme
• Aged 65 years or over
• Lives in private accommodation
• Willing and able to give informed consent

Exclusion Criteria:

• Regularly sleeps on front
• Has a chest wound
• Previous reaction to, or known allergy to ECG electrodes or silicone
• Receiving palliative care

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Atrial Fibrillation; Participants with a diagnosis of atrial fibrillation (AF) who exhibited AF in previous AF screening (as part of the SAFER Programme).	Device: Electrocardiogram monitoring; Continuous monitoring using a wearable, single-lead electrocardiography (ECG) device affixed to the chest.; Device: Electrocardiogram recording; Intermittent electrocardiogram (ECG) recordings taken using a wearable device on the wrist.; Device: Photoplethysmogram monitoring; Photoplethysmogram monitoring using a wearable device on the wrist.; Other: Feedback questionnaire; A questionnaire to collect feedback on participants' experiences of wearing the devices.
Non-Atrial Fibrillation; Participants without a diagnosis of atrial fibrillation (AF) who have previously undergone AF screening (as part of the SAFER Programme).	Device: Electrocardiogram monitoring; Continuous monitoring using a wearable, single-lead electrocardiography (ECG) device affixed to the chest.; Device: Electrocardiogram recording; Intermittent electrocardiogram (ECG) recordings taken using a wearable device on the wrist.; Device: Photoplethysmogram monitoring; Photoplethysmogram monitoring using a wearable device on the wrist.; Other: Feedback questionnaire; A questionnaire to collect feedback on participants' experiences of wearing the devices.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The performance of each wrist-worn wearable approach for identifying AF participants	Sensitivity and specificity	7 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The time for which participants report wearing the wearables	Duration of time, expressed as median (lower, upper quartiles)	7 days
The number of wrist-ECG recordings taken by participants	Median (lower, upper quartiles)	7 days
The proportion of participants in whom AF was observed, who recorded a wrist-ECG signal during an AF episode	Percentage	7 days
Participant-reported experiences of wearing the wearables	Feedback obtained from questionnaires (including some responses provided on a Likert Scale with options 'Strongly agree', 'Agree', 'Neither agree nor disagree', 'Disagree', and 'Strongly disagree').	Day 8
Device packs lost in transit	The number for both outward and return legs	Day 1, end of participation
The time for which each device attempts to record signals	The time from the wearable being first applied to the time of either it being finally removed, or its battery running out (whichever occurs first). Expressed as median (lower, upper quartiles)	7 days
The time for which wearable signals are acquired	Duration of time, and proportion of recording time, expressed as median (lower, upper quartiles). 'Wearable signal' is defined as a non-flat-line signal.	7 days
The proportion of recording time for which wearable signals are of high quality	Percentage, expressed as median (lower, upper quartiles)	7 days
The proportion of recording time for which high quality wearable signals are acquired at different times of day	Percentages, expressed as median (lower, upper quartiles)	7 days
The agreement between interbeat-intervals (IBIs) provided by IBI wristbands, and derived from reference ECG chest-patch signals	Limits of Agreement technique (consisting of the bias and limits of agreement)	7 days
The agreement between ECG features derived from wrist-ECGs and reference ECG chest-patch signals.	Limits of Agreement technique (consisting of the bias and limits of agreement)	7 days
The performance of an algorithm to detect AF from wrist-ECG signals	sensitivity and specificity	7 days
The performance of an algorithm to detect possible AF from IBI wristband signals	Sensitivity and specificity	7 days
The proportion of possible AF episodes detected from IBI wristband signals for which the reference ECG exhibited a verified AF episode lasting for ≥ 90 seconds from the start time of the possible episode	Percentage, expressed as median (lower, upper quartiles)	7 days
The agreement between AF burden estimates obtained from wrist devices and the reference ECG chest-patch	Limits of Agreement technique (consisting of the bias and limits of agreement)	7 days

Collaborators and Investigators

• Sponsor: University of Cambridge
• Collaborators: University of Leicester; City, University of London
• Investigators: Principal Investigator: Peter H Charlton, MEng, PhD, University of Cambridge

Study record dates

Study Major Dates

• Study Start (Actual): February 2, 2023
• Primary Completion (Estimated): May 23, 2025
• Study Completion (Estimated): May 23, 2025

Study Registration Dates

• First Submitted: January 14, 2021
• First Submitted That Met QC Criteria: January 19, 2021
• First Posted (Actual): January 20, 2021

Study Record Updates

• Last Update Posted (Actual): April 8, 2025
• Last Update Submitted That Met QC Criteria: April 4, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Photoplethysmography; Ergonomics; Arrhythmias, Cardiac; Wearable Electronic Devices; Electrocardiography, Ambulatory; Diagnostic Screening Programs
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Atrial Fibrillation
• Other Study ID Numbers: IRAS 283812; FS/20/20/34626 (Other Grant/Funding Number: British Heart Foundation); 20/EM/0255 (Other Identifier: REC reference)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

The following data from individual participants will be anonymised and shared:

• Participant characteristics
• Quantitative questionnaire data (providing feedback on the wearable devices)
• Device data including physiological signals, physiological parameters, and technical parameters.

• IPD Sharing Time Frame: Data will be made available within 12 months of the study ending. It will made available indefinitely via an online repository.
• IPD Sharing Access Criteria: None planned
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No