Rationale and design of NUDGE-FLU-CHRONIC and NUDGE-FLU-2: Two nationwide randomized trials of electronic nudges to increase influenza vaccination among patients with chronic diseases and older adults during the 2023/2024 influenza season
- PMID: 38460754
- DOI: 10.1016/j.ahj.2024.03.003
Rationale and design of NUDGE-FLU-CHRONIC and NUDGE-FLU-2: Two nationwide randomized trials of electronic nudges to increase influenza vaccination among patients with chronic diseases and older adults during the 2023/2024 influenza season
Abstract
Background: Yearly influenza vaccination is strongly recommended for older adults and patients with chronic diseases including cardiovascular disease (CVD); however, vaccination rates remain suboptimal, particularly among younger patients. Electronic letters incorporating behavioral nudges are highly scalable public health interventions which can potentially increase vaccination, but further research is needed to determine the most effective strategies and to assess effectiveness across different populations. The purpose of NUDGE-FLU-CHRONIC and NUDGE-FLU-2 are to evaluate the effectiveness of electronic nudges delivered via the Danish governmental electronic letter system in increasing influenza vaccination among patients with chronic diseases and older adults, respectively.
Methods: Both trials are designed as pragmatic randomized implementation trials enrolling all Danish citizens in their respective target groups and conducted during the 2023/2024 influenza season. NUDGE-FLU-CHRONIC enrolls patients aged 18-64 years with chronic diseases. NUDGE-FLU-2 builds upon the NUDGE-FLU trial conducted in 2022/2023 and aims to expand the evidence by testing both previously successful and new nudges among adults ≥65 years during a subsequent influenza season. Persons with exemptions from the electronic letter system are excluded from both trials. In both trials, participants are randomized in a 2.45:1:1:1:1:1:1 ratio to either receive no electronic letter (usual care) or to receive one of 6 different behaviorally informed electronic letters. NUDGE-FLU-CHRONIC has randomized 299,881 participants with intervention letters delivered on September 24, 2023, while NUDGE-FLU-2 has randomized 881,373 participants and delivered intervention letters on September 13, 2023. Follow-up is currently ongoing. In both trials, the primary endpoint is receipt of influenza vaccination on or before January 1, 2024, and the secondary endpoint is time to vaccination. Clinical outcomes including respiratory and cardiovascular hospitalizations, all-cause hospitalization, and mortality are included as prespecified exploratory endpoints. Prespecified individual-level pooled analyses will be conducted across NUDGE-FLU, NUDGE-FLU-CHRONIC, and NUDGE-FLU-2.
Discussion: NUDGE-FLU-CHRONIC is the first nationwide randomized trial of electronic nudges to increase influenza vaccination conducted among 18-64-year-old high-risk patients with chronic diseases. NUDGE-FLU-2 will provide further evidence on the effectiveness of electronic nudges among older adults ≥65 years. Collectively, the NUDGE-FLU trials will provide an extensive evidence base for future public health communications.
Trial registration: NUDGE-FLU-CHRONIC: Clinicaltrials.gov: NCT06030739, registered September 11, 2023, https://clinicaltrials.gov/study/NCT06030739. NUDGE-FLU-2: Clinicaltrials.gov: NCT06030726, registered September 11, 2023, https://clinicaltrials.gov/study/NCT06030726.
Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.
Conflict of interest statement
Declaration of competing interest MV has received research grant support or served on advisory boards for American Regent, Amgen, AstraZeneca, Bayer AG, Baxter Healthcare, Boehringer Ingelheim, Chiesi, Cytokinetics, Lexicon Pharmaceuticals, Novartis, Novo Nordisk, Pharmacosmos, Relypsa, Roche Diagnostics, Sanofi, and Tricog Health; has speaker engagements with AstraZeneca, Boehringer Ingelheim, Novartis, and Roche Diagnostics; and participates on clinical trial committees for studies sponsored by AstraZeneca, Bayer AG, Galmed, Occlutech, Novartis, and Impulse Dynamics. ASB has received research grant support to his institution from National Institutes of Health/National Heart, Lung, and Blood Institute, National Institutes of Health/National Institute on Aging, American College of Cardiology Foundation, and the Centers for Disease Control and Prevention and consulting fees from Sanofi Pasteur and Novo Nordisk. BLC has received consulting fees from Amgen, Cardurion, Corvia, Myokardia, and Novartis. CSL has received speaker fees and served on advisory boards for GSK, MSD, Pfizer, Takeda, and Valneva. LK has received speaker fees from Novo Nordisk, Novartis, AstraZeneca, Boehringer Ingelheim, and Bayer. SDS has received research grants from Actelion, Alnylam, Amgen, AstraZeneca, Bellerophon, Bayer, BMS, Celladon, Cytokinetics, Eidos, Gilead, GSK, Ionis, Lilly, Mesoblast, MyoKardia, NIH/NHLBI, Neurotronik, Novartis, Novo Nordisk, Respicardia, Sanofi, Theracos, US2.AI and consulted for Abbott, Action, Akros, Alnylam, Amgen, Arena, AstraZeneca, Bayer, Boehringer Ingelheim, BMS, Cardior, Cardurion, Corvia, Cytokinetics, Daiichi-Sankyo, GSK, Lilly, Merck, Myokardia, Novartis, Roche, Theracos, Quantum Genomics, Cardurion, Janssen, Cardiac Dimensions, Tenaya, Sanofi, Dinaqor, Tremeau, CellProThera, Moderna, American Regent, Sarepta, Lexicon, Anacardio, Akros, and Puretech Health. TB-S has served as chief investigator of the Sanofi financed NUDGE-FLU trial, the Sanofi financed DANFLU-1 trial, and the Sanofi financed DANFLU-2 trial, served as steering committee member of the Amgen financed GALACTIC-HF trial, the Boston Scientific financed LUX-Dx TRENDS trial, and the Boehringer Ingelheim financed EASi-KIDNEY trial, served on advisory boards for Sanofi, GSK, Amgen, and CSL Squirus, received speaker honoraria from Bayer, GSK, Novartis, GE Healthcare, and Sanofi, consulted for Novo Nordisk, IQVIA, and Parexel, and received research grants from GE Healthcare, Sanofi, Boston Scientific, AstraZeneca, and Novo Nordisk. All other authors declare no competing interests.
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