Clinical trial NCT05542004: Nationwide Utilization of Danish Government Electronic Letter System for Increasing InFLUenza Vaccine Uptake
Official title: Nationwide Utilization of Danish Government Electronic Letter System for Increasing InFLUenza Vaccine Uptake
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Influenza
Behavior and Behavior Mechanisms
Keywords: Influenza
Vaccination
Nudging
Behavioral Science
Lead sponsor: Herlev and Gentofte Hospital
Sponsor class: OTHER
Collaborators: name: Statens Serum Institut
name: Sanofi Pasteur, a Sanofi Company
First posted: 2022-09-15
Enrollment: 964870
Sex: ALL
Minimum age (years): 65
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

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. This study will investigate investigate whether digital behavioral nudges delivered via the official, mandatory Danish electronic letter system can increase influenza vaccine uptake among eligible influenza vaccination candidates.

Detailed description: The study is a prospective, randomized, open-label implementation trial. The study population will consist of persons identified as eligible for free-of-charge influenza vaccination in the Danish health system aged 18 years and above. Subjects will be identified through Danish nationwide health registries using codes from the International Classification of Diseases, 10th revision (ICD-10) and the Anatomical Therapeutic Chemical (ATC) classification system. Individuals will be randomized to 1 of 10 arms (1 control arm and 9 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. The study will be performed in collaboration with the Danish Health Data Authority and Statens Serum Institut.

Eligibility criteria: Inclusion Criteria:

1. Age \>=65 years at January 15, 2023 (eligible for free influenza vaccination in the official Danish vaccination program)
2. Access to the official, mandatory Danish electronic mailbox system

Exclusion Criteria:

1) Persons living in nursing homes

Primary outcomes:
measure: Number of participants who received an influenza vaccine
timeFrame: Up to 3 months
Secondary outcomes:
measure: Time from intervention delivery to influenza vaccination
timeFrame: Up to 3 months
Other outcomes:
measure: Number of participants with laboratory-confirmed influenza
timeFrame: Up to 8 months
measure: Number of participants with a hospitalization with influenza or pneumonia
timeFrame: Up to 8 months
measure: Number of participants with any hospitalization
timeFrame: Up to 8 months
measure: All-cause mortality
timeFrame: Up to 8 months
measure: Composite of incident heart failure, heart failure hospitalization, or cardiovascular death
timeFrame: Up to 8 months
measure: Composite of myocardial infarction, stroke, or cardiovascular death
timeFrame: Up to 8 months
measure: Composite of myocardial infarction, coronary revascularization, stroke, or cardiovascular death
timeFrame: Up to 8 months
measure: Number of participants with incident heart failure or heart failure hospitalization
timeFrame: Up to 8 months
measure: Cardiovascular death
timeFrame: Up to 8 months
measure: Number of participants with myocardial infarction
timeFrame: Up to 8 months
measure: Number of participants with coronary revascularization
timeFrame: Up to 8 months
measure: Number of participants with stroke
timeFrame: Up to 8 months
measure: Number of contacts to general practitioner (excluding vaccination visit)
timeFrame: Up to 8 months
measure: Number of participants with laboratory-confirmed COVID-19
timeFrame: Up to 8 months
measure: Number of participants with a hospitalization due to COVID-19
timeFrame: Up to 8 months
measure: Number of participants who received a COVID-19 vaccine
timeFrame: Up to 3 months
Locations:
city: Hellerup
country: Denmark
facility: Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte
state: Hovedstaden
Study officials:
affiliation: Research Director
name: Tor Biering-Sørensen, MD, PhD, MPH
role: PRINCIPAL_INVESTIGATOR
References: