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Thromb Haemost 2014; 111(06): 1167-1176
DOI: 10.1160/TH14-03-0231
New Technologies, Diagnostic Tools and Drugs
Schattauer GmbH

Feasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies

The SEARCH-AF study
Nicole Lowres
1   Cardiology Department, Concord Repatriation General Hospital, University of Sydney, Sydney, New South Wales, Australia
2   Anzac Research Institute, Sydney, New South Wales, Australia
3   Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
,
Lis Neubeck
4   The George Institute for Global Health, Sydney, New South Wales, Australia
5   Sydney Nursing School, University of Sydney, Sydney, New South Wales, Australia
,
Glenn Salkeld
6   School of Public Health, University of Sydney, Sydney, New South Wales, Australia
,
Ines Krass
7   Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
,
Andrew J. McLachlan
7   Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
8   Centre for Education and Research on Aging, Concord Repatriation General Hospital, Sydney, New South Wales, Australia
,
Julie Redfern
3   Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
4   The George Institute for Global Health, Sydney, New South Wales, Australia
,
Alexandra A. Bennett
7   Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
8   Centre for Education and Research on Aging, Concord Repatriation General Hospital, Sydney, New South Wales, Australia
,
Tom Briffa
9   School of Population Health, University of Western Australia, Perth, Western Australia, Australia
,
Adrian Bauman
6   School of Public Health, University of Sydney, Sydney, New South Wales, Australia
,
Carlos Martinez
10   Institute for Epidemiology, Statistics and Informatics GmbH, Frankfurt, Germany
,
Christopher Wallenhorst
10   Institute for Epidemiology, Statistics and Informatics GmbH, Frankfurt, Germany
,
Jerrett K. Lau
1   Cardiology Department, Concord Repatriation General Hospital, University of Sydney, Sydney, New South Wales, Australia
,
David B. Brieger
1   Cardiology Department, Concord Repatriation General Hospital, University of Sydney, Sydney, New South Wales, Australia
2   Anzac Research Institute, Sydney, New South Wales, Australia
3   Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
,
Raymond W. Sy
1   Cardiology Department, Concord Repatriation General Hospital, University of Sydney, Sydney, New South Wales, Australia
2   Anzac Research Institute, Sydney, New South Wales, Australia
3   Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
,
S. Ben Freedman
1   Cardiology Department, Concord Repatriation General Hospital, University of Sydney, Sydney, New South Wales, Australia
2   Anzac Research Institute, Sydney, New South Wales, Australia
3   Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
› Author Affiliations
Financial support: The screening study was supported by an investigator-initiated grant from Bristol-Myers Squibb/Pfizer, and a small investigator-initiated project award from Boehringer Ingelheim. Cost-effectiveness analysis was supported by an investigator-initiated grant from Bayer. AliveCor provided ECG Heart Monitors for study purposes. The investigators are not affiliated with, nor have any financial or other interest in AliveCor. Dr Redfern is funded by a Career Development and Future Leader Fellowship cofunded by the NHMRC and National Heart Foundation (APP1061793). Dr Neubeck is an NHMRC early career fellow (APP1036763). Ms Lowres is funded by a National Heart Foundation Postgraduate Scholarship (PP12S6990).
Further Information

Publication History

Received: 13 March 2014

Accepted after minor revision: 18 March 2014

Publication Date:
21 November 2017 (online)

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Summary

Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy. Pharmacists performed pulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8–2.5%); mean age 79 ± 6 years; all had CHA2DS2-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92–100%) sensitivity for AF detection and 91.4% (CI, 89–93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence. Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered.

Previous Presentation: This study was presented in part as an oral presentation at the Cardiac Society of Australia and New Zealand Conference; 9 August 2013; Sydney, Australia, abstract published in Heart Lung Circulation 2013;22:S223.

Trial registration: Australian New Zealand clinical trials registry: ACTRN12612000406808.

Keywords

Atrial fibrillation - screening - stroke prevention - cost-effectiveness - anticoagulation