AN INNOVATIVE study presented at the American Heart Association’s Scientific Sessions 2024 in Chicago has demonstrated that electronic messages highlighting the cardiovascular benefits of flu vaccination significantly improved vaccination rates among more than two million adults in Denmark. The research focused on bridging gaps in flu vaccine uptake, particularly among individuals with a history of heart attacks.
Influenza vaccination plays a dual role in preventing the flu and reducing major cardiovascular risks in patients with prior heart attacks. Despite these benefits, vaccination rates are often suboptimal, especially among younger adults with chronic diseases. To address this issue, the study used Denmark’s governmental electronic letter system to deliver behavioural science-informed nudges during the 2022–2023 and 2023–2024 flu seasons. Participants were randomly assigned to receive an electronic message encouraging flu vaccination or to receive no message.
The results revealed a clear impact as vaccination rates rose by 1.8% among heart attack survivors and by 1.3% in adults without a history of heart attack. Among heart attack survivors, a message specifically explaining the cardiovascular benefits of flu shots was particularly effective, leading to a 3.9% increase in vaccination rates compared to a 2% rise among those without such a history. The intervention was even more successful among previously unvaccinated heart attack survivors, where it achieved a remarkable 14% improvement in vaccine uptake. Younger adults with a recent heart attack also responded strongly, with vaccination rates increasing by 26%.
The findings highlight the importance of tailoring strategies to high-risk groups, supporting the use of cardiovascular-focused messaging as part of broader efforts to improve flu vaccination rates. However, these nudges alone are insufficient to close all vaccination gaps, and additional strategies will be necessary to fully address the issue.
The study underscores the potential of low-cost, scalable interventions to enhance public health outcomes. While Denmark’s high baseline vaccination rates may have influenced the results, ongoing validation efforts in the United States and other countries could confirm the global applicability of this approach.
Katie Wright, EMJ
Reference
Bhatt AS et al. Email reminders improved flu shot rates in Denmark, notably among heart attack survivors. Abstract 4171521. AHA Scientific Sessions, 16-18 November, 2024.
