ImportanceInfluenza vaccination in patients with acute myocardial infarction (AMI) reduces major adverse cardiac events and is strongly recommended in clinical practice guidelines. Effective strategies to improve vaccination are needed in these high-risk patients.ObjectiveTo evaluate whether electronically delivered behavioral nudges improve influenza vaccine uptake in patients with AMI across 3 nationwide implementation randomized clinical trials (RCTs).Design, Setting, and ParticipantsNationwide Utilization of Danish Government Electronic Letter System for Increasing Influenza Vaccine Uptake (NUDGE-FLU), Nationwide Utilization of Danish Government Electronic Letter System for Confirming the Effectiveness of Behavioral Nudges in Increasing Influenza Vaccine Uptake Among Older Adults (NUDGE-FLU-2), and Nationwide Utilization of Danish Government Electronic Letter System for Increasing Influenza Vaccine Uptake Among Adults With Chronic Disease (NUDGE-FLU-CHRONIC) were RCTs conducted during the 2022 to 2023 and 2023 to 2024 influenza seasons in Denmark. Participants were randomized to either usual care or various behaviorally informed, electronically delivered, letter-based nudges. In a prespecified participant-level pooled meta-analysis, interaction of AMI status on the effects of letter-based nudges vs usual care was examined. Pooled treatment effects were estimated using binomial regression models with identity link, adjustment for trial, and 2-way clustered SEs at the household and participant levels. Effect modification by recency of AMI as a continuous variable was assessed using restricted cubic spline modeling in NUDGE-FLU-CHRONIC.InterventionsBehaviorally informed, electronically delivered, letter-based nudges or usual care.Main Outcome and MeasuresThe primary end point was influenza vaccination receipt.ResultsOf 2 146 124 individual randomizations (mean [SD] age, 71.1 [11.6] years; 1 114 725 female [51.9%]) across all 3 trials, 59 458 (2.8%) had a history of AMI. Improvement in vaccine uptake was similar in patients with vs without a history of AMI who received any nudge letter compared with usual care (+1.81 vs +1.32 percentage points; P for interaction by AMI status = .09). A letter highlighting the cardiovascular benefits of vaccination (ie, cardiovascular-gain frame) resulted in larger improvements in vaccine uptake among patients with (vs without) a history of AMI (+3.91 vs +2.03 percentage points; P for interaction by AMI status = .002). Among patients with AMI, the benefits of the cardiovascular-gain frame letter were more pronounced in those not vaccinated in the prior season (+13.7 vs +1.48 percentage points; P for interaction <.001). Among younger participants with chronic disease, the cardiovascular-gain frame letter was particularly effective in patients with more recent AMI (P for interaction by continuous recency of AMI <.001).Conclusions and RelevanceAcross 3 nationwide RCTs of Danish citizens, messaging emphasizing the cardiovascular benefits of vaccination improved influenza vaccination uptake, with greater benefits observed in patients with a history of AMI. This low-cost, scalable implementation strategy should be considered to encourage influenza vaccination in high-risk patients.Trial RegistrationClinicalTrials.gov Identifiers: NCT05542004, NCT06030726, NCT06030739

中文翻译：

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有心肌梗死病史患者的电子轻推和流感疫苗接种


重要性急性心肌梗死 （AMI） 患者接种流感疫苗可减少主要不良心脏事件，在临床实践指南中强烈建议接种。这些高危患者需要有效的策略来改善疫苗接种。目的在 3 项全国实施随机临床试验 （RCT） 中评估电子传递的行为助推是否能改善 AMI 患者的流感疫苗接种率。设计、设置和参与者在全国范围内使用丹麦政府电子信件系统来提高流感疫苗的接种率 （NUDGE-FLU），在全国范围内使用丹麦政府电子信件系统来确认行为助推在增加老年人流感疫苗接种率 （NUDGE-FLU-2） 方面的有效性，以及在全国范围内使用丹麦政府电子信件系统来提高慢性病成人患者的流感疫苗接种率（NUDGE-FLU-CHRONIC） 是在 2022 年至 2023 年和 2023 年至 2024 年流感季节在丹麦进行的随机对照试验。参与者被随机分配到常规护理或各种行为知情、电子交付、基于字母的推动。在预先指定的参与者水平汇总荟萃分析中，研究了 AMI 状态对基于字母的轻推与常规护理影响的相互作用。使用具有身份链接、试验调整和 2 向聚类 SE 的二项式回归模型在家庭和参与者层面估计合并治疗效果。在 NUDGE-FLU-CHRONIC 中使用受限三次样条模型评估 AMI 作为连续变量的近因的效应修改。干预行为知情、电子交付、基于信件的推动或常规护理。主要结局和测量主要终点是接受流感疫苗接种。结果在所有 3 项试验中，2 146 124 例个体随机分组 （平均 [SD] 年龄，71.1 [11.6] 岁;1 114 725 名女性 [51.9%]），59 458 例 （2.8%） 有 AMI 病史。与常规护理相比，接受任何轻推信的 AMI 患者与无 AMI 病史的患者在疫苗接种率方面的改善相似（+1.81 vs +1.32 个百分点;按 AMI 状态交互的 P = .09）。一封强调疫苗接种对心血管益处的信（即心血管增益框架）导致有（与无）AMI 病史的患者的疫苗接种率有更大的改善（+3.91 vs +2.03 个百分点;按 AMI 状态交互的 P = .002）。在 AMI 患者中，心血管增益框架字母的好处在上一季未接种疫苗的患者中更为明显（+13.7 vs +1.48 个百分点;P 表示交互 <。在患有慢性病的年轻参与者中，心血管增益框架字母对最近 AMI 的患者特别有效 （P 通过 AMI 的持续新近度 < 进行交互。001).结论和相关性在丹麦公民的 3 项全国性 RCT 中，强调疫苗接种对心血管有益的信息提高了流感疫苗接种率，在有 AMI 病史的患者中观察到更大的益处。应考虑这种低成本、可扩展的实施策略，以鼓励高危患者接种流感疫苗。试验注册临床试验。gov 标识符：NCT05542004、NCT06030726、NCT06030739