Behavior and Behavior Mechanisms, Influenza
Conditions
Keywords
Influenza, Vaccination, Nudging, Behavioral Science, Randomized Trial, Registry
Brief summary
In randomized clinical trials and observational studies, influenza vaccination has been shown to be effective in reducing influenza-related illness, hospitalizations, cardiovascular events, and mortality in select populations. However, the real-world effectiveness of influenza vaccination is limited by its uptake. Conducted during the 2023/2024 influenza season, the first NUDGE-FLU-CHRONIC trial demonstrated the effectiveness of behavioral nudging letters in increasing influenza vaccination rates among adults aged 18-64 years with chronic diseases in Denmark. This present study will once again investigate whether digital behavioral nudges delivered via the official, mandatory Danish electronic letter system can increase influenza vaccine uptake among adults aged 18-64 years with chronic diseases including whether the effectiveness of the previously successful strategies can be confirmed during a subsequent influenza season.
Detailed description
The study is a prospective, randomized, open-label implementation trial. The study population will consist of persons aged 18-64 years identified as eligible for free-of-charge influenza vaccination due to a chronic condition. Subjects will be identified through Danish nationwide health registries using codes from the International Classification of Diseases, 10th revision (ICD-10). Individuals will be randomized to 1 of 7 arms (1 usual care arm and 6 intervention arms) with each testing different nudging strategies employing various behavioural economic principles. The interventions will be delivered through the official, mandatory Danish electronic letter system. All subject data will be retrieved from the Danish nationwide registries with the exception of information on intervention allocation. Endpoints will be retrieved at prespecified dates using prespecified search algorithms.
Interventions
BEHAVIORALBehavioral Economic Principles
The control arm will receive no letter to reflect the background vaccination uptake. Intervention arms will test the effects of different letters developed using behavioral economic principles.
Sponsors
Tor Biering-Sørensen
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
No
Inclusion criteria
1. Age 18-64 years 2. Must be registered in the Danish nationwide registries as meeting at least one of the following eligibility criteria for free-of-charge influenza vaccination in the Danish public health system: 1. Chronic lung disease 2. Chronic cardiovascular disease other than hypertension 3. Type 1 or type 2 diabetes mellitus 4. Congenital or acquired immunodeficiency 5. Impaired breathing due to muscular weakness 6. Chronic renal or hepatic insufficiency 7. Other chronic conditions with an increased risk of severe influenza as determined by the treating physician 3. Access to the official, mandatory Danish electronic mailbox system
Exclusion criteria
None
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Number of participants who received an influenza vaccine | Up to 3 months |
Secondary
| Measure | Time frame |
|---|---|
| Time from intervention delivery to influenza vaccination | Up to 3 months |
Other
| Measure | Time frame |
|---|---|
| Number of participants with a hospitalization for influenza or pneumonia | Up to 8 months |
| Number of participants with a hospitalization for any respiratory disease | Up to 8 months |
| Number of participants with a hospitalization for any cardio-respiratory disease | Up to 8 months |
| Number of participants with a hospitalization for any cardiovascular disease | Up to 8 months |
| Number of participants with any hospitalization | Up to 8 months |
| Total number of hospitalizations (first and recurrent) | Up to 8 months |
| All-cause mortality | Up to 8 months |
| Composite of incident heart failure, heart failure hospitalization, or cardiovascular death | Up to 8 months |
| Composite of myocardial infarction, stroke, or cardiovascular death | Up to 8 months |
| Composite of myocardial infarction, coronary revascularization, stroke, or cardiovascular death | Up to 8 months |
| Number of participants with incident heart failure or heart failure hospitalization | Up to 8 months |
| Total number of heart failure events (incident heart failure and first and recurrent heart failure hospitalizations) | Up to 8 months |
| Cardiovascular death | Up to 8 months |
| Number of participants with myocardial infarction | Up to 8 months |
| Number of participants with coronary revascularization | Up to 3 months |
| Number of participants with stroke | Up to 8 months |
| Number of participants with incident atrial fibrillation or atrial fibrillation hospitalization | Up to 8 months |
| Number of contacts to general practitioner (excluding vaccination visit) | Up to 8 months |
| Number of participants with laboratory-confirmed COVID-19 | Up to 8 months |
| Number of participants with a hospitalization for COVID-19 | Up to 8 months |
| Number of participants who received a COVID-19 vaccine | Up to 3 months |
| Number of participants who filled a prescription for any guideline-directed medical therapy for heart failure | Up to 8 months |
| Total number of filled prescriptions for guideline-directed medical therapy for heart failure | Up to 8 months |
| Number of participants who filled a prescription for a sodium-glucose cotransporter 2 inhibitor or glucagon-like peptide 1 receptor agonist | Up to 8 months |
| Number of participants with laboratory-confirmed influenza | Up to 8 months |
Countries
Denmark
Outcome results
None listed