Effectiveness of SMS Nudging to Increase Coverage of Influenza Vaccination Among the Elderly

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

NOT_YET_RECRUITING

Clinical Phase

NA

Total Enrollment

1000000 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-10-31

Study Completion Date

2026-07-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The trial will investigate to what extent SMS reminders for influenza vaccination increases coverage of influenza vaccination among elderly from the majority population, and among elderly from immigrant groups with low vaccination coverage

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Nationwide Utilization of Danish Government Electronic Letter System for Confirming the Effectiveness of Behavioral Nudges in Increasing InFLUenza Vaccine Uptake Among Older Adults

NCT06030726

Influenza Behavior and Behavior Mechanisms

COMPLETED NA

Impact on Influenza Vaccination Rates of a Telephone Text Message Recall From the Attending Physician

NCT06123936

Influenza Viral Infections

RECRUITING NA

Influenza Reminder Text-Messaging

NCT06587984

Influenza

COMPLETED NA

Personalized Nudging to Increase Influenza Vaccinations

NCT06566534

Influenza, Human

COMPLETED NA

Collaborative Efforts to Increase Flu Vaccination

NCT01403649

Influenza Collaboration

COMPLETED NA

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Background: The coverage of influenza vaccination among elderly in Norway is insufficient, especially in some immigrant groups. To improve public health, there is a need for an intervention that can increase influenza vaccination coverage. Further, interventions tailored to reduce potential barriers among immigrants can reduce health inequities.

Objective: InfluSMS aims to determine if SMS nudging increases vaccination coverage among those aged 65 or older (i) in Norway's general population; (ii) among immigrants born in Poland; (iii) among immigrants born in Ukraine; and to evaluate the impact of SMS nudging in Norwegian versus in the official language of the native country of immigrants born in Poland or Ukraine.

Methods: InfluSMS is a pragmatic randomized controlled trial conducted among people aged 65 or older residing in Norway. Influenza vaccination coverage is the main outcome, measured in control and intervention arms for each of the three populations listed above. In all three populations, the control arm is standard care, i.e., no individual reminder for influenza vaccination. All populations have an intervention arm that will receive an SMS nudge in the Norwegian language. In addition, the Polish and Ukrainian immigrant populations include a second intervention arm that will receive an SMS nudge in Polish or Ukrainian, respectively. Allocation to study arm is randomized, and the intervention will take place at the start of the 2025/2026 influenza season. All eligible individuals will be passively followed up through the National Immunisation Registry SYSVAK, from which individual influenza vaccination status three months after the SMS nudge will be extracted.

Results: Inclusion of participants will start in the third quarter of 2025, and the registry data will be available in the first quarter of 2026. Coverage rates of each strategy, and coverage differences between strategies will be presented.

Implications: SMS nudging could be integrated into the national influenza vaccination program if the trial shows it effectively increases influenza vaccination coverage among the elderly. Further, the trial will establish whether language is a barrier for influenza vaccination uptake among recent immigrant groups that have low influenza vaccination coverage, and to what extent this potential barrier can be diminished by SMS nudging in the official language of their native country.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Influenza

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

The trial is conducted in three populations of elderly (aged 65 years or older) residing in Norway: (i) the general population; (ii) immigrants born in Poland; (iii) immigrants born in Ukraine. In all three populations, the control arm is standard care, i.e., no individual reminder for influenza vaccination. All populations have an intervention arm that will receive an SMS nudge in the Norwegian language. In addition, the Polish and Ukrainian immigrant populations include a second intervention arm that will receive an SMS nudge in Polish or Ukrainian, respectively.

Primary Study Purpose

HEALTH_SERVICES_RESEARCH

Blinding Strategy

SINGLE

Outcome Assessors

The outcome measure of the trial is based solely on routinely collected data and those reporting/registering this information will not be aware of whether a vaccinated individual has received an SMS nudge. Thus, the trial is blinded to the outcomes assessor. Moreover, treatment allocation is randomized and computer-generated, there is no interaction between the InfluSMS project team and study participants, and the InfluSMS researchers work with de-identified data and do not know the identity of any participant in the dataset. Due to the inherent characteristics of the intervention, treatment allocation cannot be blinded for participants.

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Control

Standard care: Influenza vaccination is generally recommended to all individuals aged 65 or older, but there is no systematic individual invitation/reminding/scheduling for vaccination by SMS or any other mode. The control arm is applicable to all three populations (general population, immigrants born in Poland, immigrants born in Ukraine)

Group Type NO_INTERVENTION

No interventions assigned to this group

Norwegian SMS

Group Type EXPERIMENTAL

Norwegian SMS

Intervention Type BEHAVIORAL

Individuals receive a SMS in Norwegian language at the start of the influenza season, to remind them they are recommended to get the influenza vaccine. This intervention arm is applicable to all three populations (general population, immigrants born in Poland, immigrants born in Ukraine)

Polish/Ukrainian SMS

Group Type EXPERIMENTAL

Polish/Ukrainian SMS

Intervention Type BEHAVIORAL

Individuals receive an SMS in the official language of their native country (i.e., Polish or Ukrainian) at the start of the influenza season, to remind them they are recommended to get the influenza vaccine. This intervention arm is only applicable to the two immigrant populations (immigrants born in Poland, immigrants born in Ukraine)

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Norwegian SMS

Individuals receive a SMS in Norwegian language at the start of the influenza season, to remind them they are recommended to get the influenza vaccine. This intervention arm is applicable to all three populations (general population, immigrants born in Poland, immigrants born in Ukraine)

Intervention Type BEHAVIORAL

Polish/Ukrainian SMS

Individuals receive an SMS in the official language of their native country (i.e., Polish or Ukrainian) at the start of the influenza season, to remind them they are recommended to get the influenza vaccine. This intervention arm is only applicable to the two immigrant populations (immigrants born in Poland, immigrants born in Ukraine)

Intervention Type BEHAVIORAL

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Aged 65+ (age at the end of 2025, i.e., born 1960 or earlier)
* Resident in Norway and have a valid ID number on 1 September 2025
* Have a registered mobile phone number