Secondary analysis
Effect of Electronic Nudges on Influenza Vaccination Rate in Older Adults With Cardiovascular Disease: Prespecified Analysis of the NUDGE-FLU Trial
- Prespecified secondary analysis of the NUDGE-FLU randomised trial
- pragmatic
- nationwide
- register-based
- household randomisation 9:1:1:1:1:1:1:1:1:1
Authors' conclusion
Electronic letter interventions emphasizing the potential cardiovascular benefits of influenza vaccination and using a reminder letter strategy were similarly beneficial in increasing influenza vaccination rates among older adults with and without CVD and across cardiovascular subgroups.
Study context
- Population
- Danish citizens aged ≥65 years, 2022–2023 influenza season, with and without cardiovascular disease (CVD)691,820 households
- Participants
- 964,870 participants
- Comparison
- Electronic letter nudges vs usual care, by presence of CVD
- Primary endpoint
- Receipt of an influenza vaccine
- Follow-up
- On or before January 1, 2023
Primary result
As reported in the abstract
Influenza vaccination, by CVD status (subgroup analysis)
- CV benefit letter · CVD
- absolute difference +0.60 percentage points (99.55% CI −0.48 to 1.68)
- CV benefit letter · no CVD; interaction P=0.41
- absolute difference +0.98 percentage points (99.55% CI 0.27–1.70)
- Repeated letter · CVD
- absolute difference +0.80 percentage points (99.55% CI −0.27 to 1.86)
- Repeated letter · no CVD; interaction P=0.77
- absolute difference +0.67 percentage points (99.55% CI −0.06 to 1.40)
Further findings
Vaccination rate, CVD vs no CVD
P < 0.001
- Vaccination rate, CVD vs no CVD: 264 392 (27.4%) had CVD
Original publication
Effect of Electronic Nudges on Influenza Vaccination Rate in Older Adults With Cardiovascular Disease: Prespecified Analysis of the NUDGE-FLU Trial. Circulation. Published 5 March 2023. doi:10.1161/circulationaha.123.064270
Summarised from the published abstract; every number is checked against it