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The potential impact of atrial fibrillation screening in Ireland
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Date
2023
Authors
Callanan, Aileen
Journal Title
Journal ISSN
Volume Title
Publisher
University College Cork
Published Version
Abstract
Background
Atrial fibrillation (AF) is the most commonly diagnosed cardiac arrhythmia globally (1-4)and is a major risk factor for ischaemic stroke (5, 6), with stroke risk increasing five-fold in the presence of AF (6). However, AF is frequently asymptomatic, and this coupled with its intermittent nature, makes diagnosis difficult (5). If identified, treatment is available which reduces stroke risk by up to two thirds (7, 8). The two primary treatment options for AF are electrical cardioversion or cardioversion with anti-arrhythmic medication or rate control drugs (9). Guidelines also recommend the use of OAC based on individual thromboembolic risk (9, 10). AF screening meets many of the World Health Organisation (WHO) criteria for screening (11) and is recommended nationally (12) and internationally (2). However, to date there is no national screening programme for AF in Ireland.
A community setting such as general practice has been identified as a potential location to conduct AF screening and mobile ECG devices have been reported as the preferred screening tools (13). In Ireland, opportunistic AF case finding via pulse palpation was introduced as part of a new chronic disease management programme in January 2020 to a proportion of the population ≥ 75 years, it is available to those who are covered under the national health insurance scheme (14).
Studies have reported increased morbidity and mortality associated with AF related stroke compared to non-AF related stroke (1, 15). Previously, there are no robust estimates of the burden (disability and death) associated with AF related stroke and non-AF related stroke in Ireland.
This thesis (i) estimates the burden (disability and death) of AF and non-AF related strokes in the Irish context, (ii) identifies facilitators and barriers to AF screening from the perspectives of general practitioners (GPs) in primary care, and (ii) quantifies the yield and feasibility of a pilot AF screening programme in primary care in the south of Ireland.
Aims
The overall aim of this thesis was to explore the feasibility of opportunistic AF screening in primary care in Ireland with one-lead ECG technology.
Specific aim 1: to estimate the burden of AF by investigating the association between AF related and non-AF related stroke with severe stroke outcomes and death in Ireland.
Specific aim 2: to identify facilitators and barriers to AF screening in primary care in Ireland from the perspectives of GPs.
Specific aim 3: to implement a pilot AF screening programme in primary care in Ireland using one-lead ECG technology.
Methods
A multiphase mixed method design including quantitative research conducted concurrently with an exploratory sequential design was adopted for this thesis. Three studies were conducted during the three-year research period:
• Study 1 – a secondary data analysis of the Irish National Audit of Stroke (INAS).
• Study 2 –a qualitative descriptive study of GPs in primary care.
• Study 3 – a pilot AF screening programme in primary care in the south of Ireland.
The secondary data analysis of the Irish National Audit of Stroke provides robust evidence regarding the burden of AF related stroke in Ireland and highlights the need for further stroke prevention efforts based on the magnitude of morbidity and mortality associated with AF related stroke. Data from the qualitative study was used to inform the pilot AF screening programme. Facilitators and barriers which were identified in this study were incorporated into the design of the pilot AF screening programme. The pilot AF screening study provides real world evidence regarding the implementation of an AF screening programme using one-lead ECG technology.
Data from INAS were analysed using Stata SE version 17.0 statistical package. The modified Rankin scale (mRS) was used as a measure of disability. Students t-test was used to analyse difference in numeric variables, displayed as mean, minimum, maximum, range and standard deviation, Chi-square tests were used to analyse categorical variables, reported as numbers and proportions. Logistic regression was used to investigate the association between AF related stroke and non-AF related stroke, disability and death.
Study 2 was a qualitative descriptive study of GPs in primary care to identify facilitators and barriers to AF screening from their perspectives. A total of 58 GPs were invited from the north Cork region to participate in individual interviews at their practices, rural and urban, with a view to recruiting a sample of up to 12 GPs. The interviews were audio-recorded, transcribed verbatim and analysed using framework analysis.
Study 3 was a pilot AF screening programme in primary care in the south of Ireland using a one-lead ECG device, KardiaMobile. General practitioners (GPs) were recruited from Cork and Kerry and invited patients ≥65 years to undergo a stroke prevention initiative compromising AF screening, blood pressure check and identification of smoking status. Descriptive statistics were carried out using Stata SE 17.0 statistical package.
Results
Quantitative study; the association between AF related stroke and stroke severity, disability and death. During the three-year study period, 10,528 ischaemic strokes were recorded by INAS, 4489 (43%) were female with a mean age of 74 (SD 13) years. AF related strokes were found to account for approximately 31% of ischaemic strokes. Patients with AF related stroke were on average older 78 (SD 9.9) than those without AF 70 (SD14), (p<0.001) and a higher proportion were females 1433 (45%) (p 0.008). Having a severe stroke (modified Rankin scale measuring disability) was more likely in the AF related stroke group in the univariate model, OR 2.1 (1.9-2.3, p<0.001), and the multivariate model including sex, age, social position (using GMS national health insurance cover as a proxy), marital status and admission to a stroke unit, OR 1.4 (1.3-1.6, p<0.001). The association remained in sensitivity analyses and subgroup analyses providing robust estimates. The increased risk of morbidity and mortality in this study demonstrates the additional burden of AF related stroke and the potential importance of AF screening to identify unknown AF cases who can be assessed for treatment.
Qualitative study; identification of facilitators and barriers to AF screening: Eight GPs, four male, four female from five practices participated. Five were from urban practices, three were from rural practices. Facilitators and barriers were sub-categorised into patient facilitators, practice facilitators, GP facilitators, patient barriers, practice barriers, GP barriers, attitudes to AF screening, willingness to facilitate and priority ranking. All eight participants expressed a willingness to engage in AF screening. Time constraints was the barrier discussed most frequently by all participants along with the need for additional staff. Programme structure was the most discussed facilitator by all participants and patient awareness campaigns. These findings were incorporated into the pilot AF screening programme. Cognisant to lack of time identified as a barrier to AF screening, the pilot screening programme used (i) 1-lead ECG device due to its ability to provide an ECG reading in 30 seconds and (ii) a short one-page clinical report form was used for the study to facilitate prompt data collection by participating GPs. Lack of clear onward referral pathways were also identified as a barrier. Thus, a detailed standard operating procedure (SOP) providing guidance on referral to secondary care was provided in the pilot screening programme.
The qualitative study identified important data on facilitators and barriers that may be experienced implementing an AF screening programme in primary care and these findings were integrated into the pilot AF screening programme.
Pilot AF screening study; implementation of a pilot AF screening programme in primary care in Ireland: The pilot programme was offered to over 400 GP practices. Anonymised data from 3555 eligible patients, across 34 practices (52GPs) was analysed. Of those 1720 (48%) were female, 1698 (48%) were male. The result of the screening intervention, using Kardia Mobile, was 3282 (92%) had normal readings, 101 (3%) had possible AF, 124 (4%) had unreadable or unclassified readings and 48 (1%) missing data. Of the 101 patients who had a possible AF reading, 45 (45%) had AF confirmed as per 12 lead ECG. Uptake from participants was high from both GPs and patients and the yield of the screening was 1.3%. Levels of hypertension were also high in the screened population, and it may be beneficial to incorporate AF screening into an overall stroke prevention programme focusing on a selection of the main cardiovascular risk factors including hypertension.
Conclusion
AF related stroke accounts for 31% of ischaemic strokes in Ireland and is associated with considerable disability and death. One third of AF related ischaemic stroke patients were diagnosed with AF on presentation with stroke. While a large proportion of those with AF are on OAC, approximately 80%, the findings demonstrate the potential need for screening. The secondary data analysis study identified high levels of morbidity and mortality associated with AF related stroke. This is a significant public health issue. Despite barriers to AF screening identified by GPs in the qualitative study, there was significant willingness to engage in the pilot AF screening programme as demonstrated by high uptake by GPs and patients. Early detection of AF in asymptomatic individuals enabled assessment for treatment. The high levels of high systolic BP detected are notable. It may be beneficial to conduct more comprehensive stroke risk assessments rather than AF screening in isolation.
Description
Keywords
Atrial fibrillation , Screening , Primary care
Citation
Callanan, A. 2023. The potential impact of atrial fibrillation screening in Ireland. PhD Thesis, University College Cork.