Framing and Financial Incentives to Increase Influenza Vaccination Uptake: A Randomized Controlled Trial in Chinese Communities

Last registered on October 15, 2025
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Pre-Trial

Trial Information

General Information

Title
Framing and Financial Incentives to Increase Influenza Vaccination Uptake: A Randomized Controlled Trial in Chinese Communities
RCT ID
AEARCTR-0016944
Initial registration date
October 05, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
October 06, 2025, 3:29 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
October 15, 2025, 6:17 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

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Primary Investigator

Name
Yizhi Wang
Affiliation
Tianjin University
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Other Primary Investigator(s)

PI Name
Shenshen Yang
PI Affiliation
Tianjin University
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PI Name
Xiongfei Li
PI Affiliation
University of International Business and Economics
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Additional Trial Information

Status
In development
Start date
2025-10-09
End date
2026-03-31
Keywords
Health
Additional Keywords
Influenza vaccine, framing effects, financial incentives, randomized controlled trial, belief changes
JEL code(s)
I12, I18, C93
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study evaluates how message framing and financial incentives affect influenza vaccination uptake among adults in Chinese community settings. We implement a four-arm individual-level randomized controlled trial (RCT) comparing (1) a control group with no framed information, (2) neutral factual information, (3) positive frame emphasizing benefits of vaccination, and (4) negative frame emphasizing costs of non-vaccination. All arms include an identical monetary incentive component: a 50% chance of receiving a random payment between 10–100 RMB or 0 RMB otherwise.

The experiment aims to estimate: (i) the causal effect of positive and negative frames relative to control and neutral information on vaccination uptake; (ii) heterogeneity by individual baseline beliefs and vaccination intentions (susceptible, swing, resistant groups); (iii) the mediating role of belief updating; and (iv) the joint effect of framing and incentives on subsequent influenza-related health outcomes (ILI symptoms, work absence, health care use).
External Link(s)

Registration Citation

Citation
Li, Xiongfei, Yizhi Wang and Shenshen Yang. 2025. "Framing and Financial Incentives to Increase Influenza Vaccination Uptake: A Randomized Controlled Trial in Chinese Communities." AEA RCT Registry. October 15. https://doi.org/10.1257/rct.16944-1.2
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Experimental Details

Interventions

Intervention(s)
Four treatment arms:

T0 – Control: No framed message, participants receive only basic administrative information about vaccine access and eligibility.

T1 – Neutral information: Factual message (location, timing, cost, and safety standards).

T2 – Positive frame: Information emphasizing the benefits of vaccination—protecting oneself and family, reducing absence, contributing to herd immunity.

T3 – Negative frame: Information emphasizing the risks and losses from non-vaccination—higher infection risk, potential complications, cost of illness, transmission to family.

All information arms include identical factual content and frequency (three rounds of delivery via SMS/WeChat/poster at one–two week intervals).

Financial Incentive: Participants in all groups have a 50% probability of receiving a subsidy, randomly drawn between 10–100 RMB (uniform distribution), shown after baseline survey.
Intervention Start Date
2025-10-15
Intervention End Date
2025-11-15

Primary Outcomes

Primary Outcomes (end points)
Self-reported influenza vaccination status at Follow-up 1 or 2 (binary).
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Timing of vaccination (days since intervention).

Influenza-like illness (ILI) incidence, duration, and medical visits.

Work/school absenteeism due to illness.

Change in beliefs (safety, effectiveness, perceived risk).

Recall of message content (information retention).
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Design type: Individual-level RCT with stratified block randomization.

Stratification variables: gender, age group (≤35 / 36–59 / ≥60), prior influenza vaccination (yes/no), baseline intention (low/medium/high), and risk category (susceptible, swing, resistant).

Blinding: Enumerators not blinded, but information delivery automated to minimize implementation bias.

Timeline:

Baseline (Survey 1): Before randomization; measures demographics, vaccination history, beliefs, intentions, barriers.

Follow-up 1: 2–3 weeks post-intervention (mid-season).

Follow-up 2: End of influenza season (12–16 weeks).
Experimental Design Details
Not available
Randomization Method
Computerized stratified block randomization conducted in the survey platform prior to message delivery.
Randomization Unit
Individual.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
4000 Individuals
Sample size: planned number of observations
4000 Individuals
Sample size (or number of clusters) by treatment arms
1000 Individuals for each arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Tianjin University
IRB Approval Date
2025-07-15
IRB Approval Number
TJUE2025-H-S-032
Analysis Plan