Improving knowledge and early detection of atrial fibrillation through community-based opportunistic screening and educational interventions in Tasmania

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. It can be asymptomatic and responsible for 30% of all strokes. The use of oral anticoagulants therapy (OAC) has been demonstrated to reduce the risk of AF-related stroke by between 64% to 70% in patients with AF. However, a potential barrier to the use of OAC therapy is poor knowledge and under-detection of AF in the general population. Educational interventions and screening programs could improve AF knowledge and detection in the community. While evidence from randomised controlled trials is needed to demonstrate the clinical benefit of screening, particularly among those with asymptomatic AF, available data from prospective cohort studies have shown potential benefits of screening. Therefore, this thesis aimed to improve AF knowledge and detection through community-based screening and educational interventions in Tasmania. The specific objectives were to: (i) apply the Capability, Opportunity, and Motivation Behaviour (COM-B) model to guide the development and implementation of the interventions for improving AF knowledge and detection in the community; (ii) develop and validate a tool for assessing AF knowledge of the general population; (iii) assess baseline AF knowledge of the public; (iv) develop and implement community-based AF screening and educational interventions in Tasmania; and (v) evaluate the impact of these interventions in enhancing AF knowledge of the public. Firstly, the COM-B model was applied to serve as the theoretical framework to guide the design and implementation of the interventions described in this thesis. Twenty-four factors associated with the participation of people in community-based screening for AF were identified from a review of the literature and subsequently mapped into sub-components of the COM-B model. A Behaviour Change Wheel (BCW) was used to recommend 24 potential intervention strategies and steps that could guide the design and implementation of the interventions reported in this thesis. Based on the recommendations from the model and the absence of a tool suitable for assessing AF knowledge of the general population, an AF knowledge tool was developed. The tool had satisfactory content validity, with a scale content validity index of 0.8. The tool appeared to be valid for construct validity, with acceptable internal consistency reliability, item discrimination, difficulty index, and ease of readability. The tool also had good internal consistency reliability (Cronbach's alpha = 0.91). The validated tool was utilised in an online survey using Facebook advertisements to assess AF knowledge of the public before educational interventions in Tasmania. A total of 500 participants (aged ‚Äöv¢‚Ä¢40 years old) were included in the study; 198 were from Tasmania (as the intervention site), and 302 were from mainland Australia (as the control site). The median interquartile (IQR) percentage AF knowledge score of the respondents was 61.9% (28.6 to 76.2), with no difference between the two groups. Of the total respondents, 113 (22.6%) obtained a score of ‚Äöv¢¬ß20% and were classified as having poor AF knowledge, and 76 (15.2%) respondents scored zero, suggesting a complete lack of AF knowledge. The presence of poor AF knowledge was not influenced by participant sociodemographic factors. The outcomes of the survey guided the development of the educational materials to address the identified gaps. The educational materials were found to be easy to read based on the feedback from target participants and a readability test. The educational materials were delivered to the public across Tasmania through the distribution of over 5,000 AF flyers and 500 posters; advertisements in seven newspapers; media campaigns using three local radio stations; and an online campaign through 21 websites and a Facebook advertisement. AF promotion and detection programs were implemented across Tasmania through community-based screening. A total of 1,704 eligible participants (people aged ‚Äöv¢‚Ä¢65 years) were screened at 79 sessions, using a blood pressure monitor with AF detection functionality (Microlife WatchBP Home A). Of this cohort, 50 (2.9%) and 1,654 (97.1%) had positive and negative screening results, respectively. Following AF diagnosis by general practitioners, the device correctly detected AF in 22 (46.8%) of the participants with positive screening results and produced 25 (53.2%) false-positive results. The calculated positive predictive value of the device was 46.8% (95%CI, 33.3 to 60.7). Among those with confirmed AF, 6 (27.3%) had a history of AF but were not aware of the diagnosis, and 16 (72.7%) were identified to have previously undiagnosed AF. The prevalence of previously undiagnosed AF among all participants was found to be 0.9% (95% CI, 0.58 to 1.52). Subsequently, oral anticoagulation therapy (OAC) was initiated in 12 (87.5%) participants who were eligible. The impact of the interventions in improving the AF knowledge of the general population was evaluated. Another survey included 443 eligible participants from Tasmania (n=150) and mainland Australia (n=293), and the results were compared with the baseline survey. There was a significant increase in the percentage median (IQR) AF knowledge score among respondents from Tasmania, from 57.1 (28.6 to 76.2) pre-intervention to 71.4 (57.1 to 85.7) post-intervention survey (p<0.001). A marginal increase in the median AF knowledge score was observed among the control group, from 61.9 (27.4 to 76.2) to 66.7 (42.9 to 80.9; p=0.01). For participants in Tasmania, there was a significant decrease in the percentage of those with poor AF knowledge, from 22.2% pre-intervention to 4.5% at the post-intervention assessment (p <0.001). This thesis presents the first program described in the literature to develop, validate, and implement evidence-based strategies for improving AF knowledge of the general population. Overall, the outcomes of this thesis demonstrate that the interventions were effective in enhancing AF knowledge. Although the findings suggest the possibility of implementing these interventions in the community, AF screening using the Microlife WatchBP Home A is unlikely to be feasible and cost-effective, based on the high rate of false-positive results. Therefore, more studies are needed to demonstrate the utility of this device in opportunistic screening in the community while awaiting the outcomes of large RCTs to confirm the overall clinical benefits of AF screening.