Decentralising atrial fibrillation screening to overcome socio-demographic inequalities in uptake in STROKESTOP II

Examining the continuum of resistance model in two population-based screening studies in Sweden

In studies recruited on a voluntary basis, lack of representativity may impair the ability to generalize findings to the target population. Previous studies, primarily based on surveys, have suggested that generalizability may be improved by exploiting data on individuals who agreed to participate only after receiving one or several reminders, as such individuals may be more similar to non-participants than what early participants are. Assessing this idea in the context of screenings, we compared sociodemographic characteristics and health across early, late, and non-participants in two large population-based screening studies in Sweden: STROKESTOP II (screening for atrial fibrillation; 6,867 participants) and SCREESCO (screening for colorectal cancer; 39,363 participants). We also explored the opportunities to reproduce the distributions of characteristics in the full invited populations, either by assuming that the non-participants were similar to the late participants, or by applying a linear extrapolation model based on both early and late participants. Findings showed that early and late participants exhibited similar characteristics along most dimensions, including civil status, education, income, and health examination results. Both these types of participants in turn differed from the non-participants, with fewer married, lower educational attainments, and lower incomes. Compared to early participants, late participants were more likely to be born outside of Sweden and to have comorbidities, with non-participants similar or even more so. The two empirical models improved representativity in some cases, but not always. Overall, we found mixed support that data on late participation may be useful for improving representativeness of screening studies.

Predictors of participation in atrial fibrillation screening among community residents in China

BACKGROUND

Atrial fibrillation (AF) is associated with increased stroke risk, but many cases of AF remain undiagnosed. Screening is suggested for early detection of AF. However, nonparticipation in screening is frequently reported, and the underlying causes of why patients choose to participate or not are poorly understood.

OBJECTIVES

To explore factors associated with participation in AF screening in a high-risk population in China.

METHODS

A cross-sectional study was conducted among community residents who were at risk for AF in Guangzhou, China, from February to September 2022. Data on AF knowledge, attitude, subjective norms, perceived behavioral control, and willingness to participate in AF screening were collected. Sociodemographic and clinical data were also collected. Multiple linear stepwise regression analysis was performed to explore predictors for participation in AF screening.

RESULTS

In total, 420 participants were included, with a mean age of 74.4 (±7.43) years old. The results showed that 77.4% of participants reported that they were likely to participate in AF screening. The results of multiple linear regression showed that perceived behavioral control (β =0.591, 95% CI: 0.071, 0.094), attitude (β =0.085, 95% CI: 0.001, 0.025), and having an AF diagnosis (β =0.098, 95% CI: 0.068, 0.494) were positively associated with willingness to participate in AF screening.

CONCLUSIONS

Chinese patients are more likely to participate in AF screening when they perceive great control over their behavior, hold a positive attitude, and have an AF diagnosis. The findings provide clues for future interventions aimed at improving the AF screening participation rate.

Cost-effectiveness of population screening for atrial fibrillation: the STROKESTOP study

AIMS

Previous studies on the cost-effectiveness of screening for atrial fibrillation (AF) are based on assumptions of long-term clinical effects. The STROKESTOP study, which randomised 27 975 persons aged 75/76 years into a screening invitation group and a control group, has a median follow-up time of 6.9 years. The aim of this study was to estimate the cost-effectiveness of population-based screening for AF using clinical outcomes.

METHODS AND RESULTS

The analysis is based on a Markov cohort model. The prevalence of AF, the use of oral anticoagulation, clinical event data, and all-cause mortality were taken from the STROKESTOP study. The cost for clinical events, age-specific utilities, utility decrement due to stroke, and stroke death was taken from the literature. Uncertainty in the model was considered in a probabilistic sensitivity analysis. Per 1000 individuals invited to the screening, there were 77 gained life years and 65 gained quality-adjusted life years. The incremental cost was €1.77 million lower in the screening invitation group. Gained quality-adjusted life years to a lower cost means that the screening strategy was dominant. The result from 10 000 Monte Carlo simulations showed that the AF screening strategy was cost-effective in 99.2% and cost-saving in 92.7% of the simulations. In the base-case scenario, screening of 1000 individuals resulted in 10.6 [95% confidence interval (CI): -22.5 to 1.4] fewer strokes (8.4 ischaemic and 2.2 haemorrhagic strokes), 1.0 (95% CI: -1.9 to 4.1) more cases of systemic embolism, and 2.9 (95% CI: -18.2 to 13.1) fewer bleedings associated with hospitalization.

CONCLUSION

Based on the STROKESTOP study, this analysis shows that a broad AF screening strategy in an elderly population is cost-effective. Efforts should be made to increase screening participation.

Colorectal cancer screening with fecal immunochemical testing or primary colonoscopy: An analysis of health equity based on a randomised trial

BACKGROUND

We have addressed health equity attained by fecal immunochemical testing (FIT) and primary colonoscopy (PCOL), respectively, in the randomised controlled screening trial SCREESCO conducted in Sweden.

METHODS

We analysed data on the individuals recruited between March 2014, and March 2020, within the study registered with ClinicalTrials.gov, NCT02078804. Swedish population registry data on educational level, household income, country of birth, and marital status were linked to each 60-year-old man and woman who had been randomised to two rounds of FIT 2 years apart (n = 60,123) or once-only PCOL (n = 30,390). Furthermore, we geo-coded each study individual to his/her residential area and assessed neighbourhood-level data on deprivation, proportion of non-Western immigrants, population density, and average distance to healthcare center for colonoscopy. We estimated adjusted associations of each covariate with the colonoscopy attendance proportion out of all invited to respective arms; ie, the preferred outcome for addressing health equity. In the FIT arm, the test uptake and the colonoscopy uptake among the test positives were considered as the secondary outcomes.

FINDINGS

We found a marked socioeconomic gradient in the colonoscopy attendance proportion in the PCOL arm (adjusted odds ratio [95% credibility interval] between the groups categorised in the highest vs. lowest national quartile for household income: 2·20 [2·01-2·42]) in parallel with the gradient in the test uptake of the FIT × 2 screening (2·08 [1·96-2·20]). The corresponding gradient in the colonoscopy attendance proportion out of all invited to FIT was less pronounced (1·29 [1·16-1·42]), due to higher proportions of FIT positives in socioeconomically disadvantaged groups.

INTERPRETATION

The unintended risk of exacerbating inequalities in health by organised colorectal cancer screening may be higher with a PCOL strategy than a FIT strategy, despite parallel socioeconomic gradients in uptake.

FUNDING

This work was supported by the Swedish Cancer Society under Grant 20 0719. CB and US provided economic support from the Swedish Research Council for Health, Working life, and Welfare under Grant 2020-00962.

Clinical outcomes in systematic screening for atrial fibrillation (STROKESTOP): a multicentre, parallel group, unmasked, randomised controlled trial

BACKGROUND

Atrial fibrillation is a leading cause of ischaemic stroke. Early detection of atrial fibrillation can enable anticoagulant therapy to reduce ischaemic stroke and mortality. In this randomised study in an older population, we aimed to assess whether systematic screening for atrial fibrillation could reduce mortality and morbidity compared with no screening.

METHODS

STROKESTOP was a multicentre, parallel group, unmasked, randomised controlled trial done in Halland and Stockholm in Sweden. All 75-76-year-olds residing in these two regions were randomly assigned (1:1) to be invited to screening for atrial fibrillation or to a control group. Participants attended local screening centres and those without a history of atrial fibrillation were asked to register intermittent electrocardiograms (ECGs) for 14 days. Treatment with oral anticoagulants was offered if atrial fibrillation was detected or untreated. All randomly assigned individuals were followed up in the intention-to-treat analysis for a minimum of 5 years for the primary combined endpoint of ischaemic or haemorrhagic stroke, systemic embolism, bleeding leading to hospitalisation, and all-cause death. This trial is registered with ClinicalTrials.gov, NCT01593553.

FINDINGS

From March 1, 2012, to May 28, 2014, 28 768 individuals were assessed for eligibility and randomly assigned to be invited to screening (n=14 387) or the control group (n=14 381). 408 individuals were excluded from the intervention group and 385 were excluded from the control group due to death or migration before invitation. There was no loss to follow-up. Of those invited to screening, 7165 (51·3%) of 13 979 participated. After a median follow-up of 6·9 years (IQR 6·5-7·2), significantly fewer primary endpoint events occurred in the intervention group (4456 [31·9%] of 13 979; 5·45 events per 100 years [95% CI 5·52-5·61]) than in the control group (4616 [33·0%] of 13 996; 5·68 events per 100 years [5·52-5·85]; hazard ratio 0·96 [95% CI 0·92-1·00]; p=0·045).

INTERPRETATION

Screening for atrial fibrillation showed a small net benefit compared with standard of care, indicating that screening is safe and beneficial in older populations.

FUNDING

Stockholm County Council, the Swedish Heart & Lung Foundation, King Gustav V and Queen Victoria's Freemasons' Foundation, the Klebergska Foundation, the Tornspiran Foundation, the Scientific Council of Halland Region, the Southern Regional Healthcare Committee, the Swedish Stroke Fund, Carl Bennet AB, Boehringer Ingelheim, Bayer, and Bristol Myers Squibb-Pfizer.

Large-scale screening studies for atrial fibrillation - is it worth the effort?

Atrial fibrillation (AF) is a common disease with increasing prevalence, approximately 3.2% in the adult population. In addition, about one third of AF cases are considered asymptomatic. Due to increased longevity, increased detection and increased prevalence of risk factors, the prevalence of AF is expected to at least double by the year 2060. Patients with AF have an increased risk for ischaemic stroke, heart failure, death and cognitive decline. Treatment with oral anticoagulation reduces the risk of ischaemic stroke and mortality, and the effect on cognitive decline is being studied. Based on the increasing prevalence of AF, its often asymptomatic and paroxysmal presentation and the efficacy of oral anticoagulation treatment, screening for AF has been proposed. AF seems to fulfil most of the Wilson-Jungner criteria for screening issued by the World Health Organization, but some knowledge gaps remain, gaps that will be addressed by several ongoing studies. The knowledge gaps in AF screening consist of the magnitude of the net benefit or net harm inflicted by AF screening because the oral anticoagulation treatment will also increase the risk of bleeding, and the psychological effects of AF screening are not very well studied. So far, the AF screening recommendations issued by the European Society of Cardiology have had limited impact on national and regional AF screening activities. Several large-scale AF screening studies will report results on hard endpoints within the next few years, and these results will hopefully manifest AF as a cardiovascular disease which we need to pay more attention to.

Facilitating participation in cardiovascular preventive initiatives among people with diabetes: a qualitative study

Background

Type 2 diabetes (T2D) is associated with a significantly increased risk of cardiovascular disease (CVD). The DIAbetic CArdioVAscular Screening and intervention trial (DIACAVAS) was designed to clarify whether advanced imaging for subclinical atherosclerosis combined with medical treatment is an effective strategy to develop individualised treatment algorithms for Danish men and women with T2D aged 40–60. But in the DIACAVAS pilot study, the uptake was only 41%. Consequently, we explored how people experienced living with T2D to understand how to improve the uptake in initiatives targeting the prevention of CVD.

Methods

We used semi-structured interviews to obtain information on how the respondents experienced having T2D. For supplementary information, we used structured interviews on e.g. socioeconomic factors. From April to October 2019, 17 participants aged 40–60 years were recruited from general practices and diabetes outpatient clinics in Denmark. Several levels of analysis were involved consistent with inductive content analysis.

Results

The participants’ experiences of living with T2D fell along two continuums, from an emotional to a cognitive expression and from reactive to proactive disease management. This led to identification of four archetypal characteristics: (I) powerlessness, (II) empowerment, (III) health literacy, and (IV) self-efficacy. These characteristics indicated the importance of using different approaches to facilitate participation in cardiovascular preventive initiatives. Additionally, findings inspired us to develop a model for facilitating participation in future preventive initiatives.

Conclusion

Encouraging people with T2D to participate in cardiovascular preventive initiatives may necessitate a tailored invitation strategy. We propose a model for an invitational process that takes into consideration invitees’ characteristics, including powerlessness, empowerment, health literacy and self-efficacy. This model may enhance participation in such initiatives. However, participation is a general concern, not only in relation to cardiovascular prevention. Our proposed model may be applicable in preventive services for people with T2D in general.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10172-6.