Information and vaccine uptake

Last registered on November 19, 2018

View Trial History

Pre-Trial

Trial Information

General Information

Title

Information and vaccine uptake

RCT ID

AEARCTR-0003520

Initial registration date

November 19, 2018

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

November 19, 2018, 7:45 PM EST

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

Locations

Country

Finland

Region

Multiple

Primary Investigator

Name

Lauri Sääksvuori

Affiliation

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

On going

Start date

2018-10-01

End date

2019-04-30

Keywords

Health

Additional Keywords

Vaccine uptake, herd immunity, information

JEL code(s)

Secondary IDs

Abstract

We run a large-scale RCT to understand the behavioural processes that guide decisions to vaccinate. The experiment varies the text of postal letters send to individuals eligible for free influenza vaccines. The experiment is run in collaboration with the municipal health authorities in six different municipalities with historically high and low influenza vaccine coverage.

External Link(s)

Registration Citation

Citation

Sääksvuori, Lauri. 2018. "Information and vaccine uptake." AEA RCT Registry. November 19. https://doi.org/10.1257/rct.3520-1.0

Former Citation

Sääksvuori, Lauri. 2018. "Information and vaccine uptake." AEA RCT Registry. November 19. https://www.socialscienceregistry.org/trials/3520/history/37518

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

Intervention Start Date

2018-10-31

Intervention End Date

2018-11-01

Primary Outcomes

Primary Outcomes (end points)

Vaccine uptake (as recorded in the administrative Register of Primary Health Care visits)

Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)

We run the analysis by gender and municipality. We investigate the effect of our intervention separate in regions with low and high historical vaccine coverage.

Secondary Outcomes (explanation)

Experimental Design

Random assignment at household level. In two active treatment arms, individuals receive postal letters that contain information about the benefits of influence vaccines.

Experimental Design Details

Random assignment at household level. In two active treatment arms, individuals receive postal letters that contain information about the benefits of influence vaccines.

Randomization Method

Randomization at office using computer code (Stata)

Randomization Unit

Households (including single households and couples)

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

Control treatment: 1739 clusters
T1: 16436 clusters
T2: 16436 clusters

Sample size: planned number of observations

Control treatment: 2466 individuals T1: 22839 individuals T1: 22839 individuals

Sample size (or number of clusters) by treatment arms

See above.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Not straightforward to compute as cluster size varies (household size is either 1 or 2). A very conservative estimate assuming interclass correlation 1 and sd. 0.5 gives a minimal detectable effect size 1.55ppt for treatment comparison T1 vs. T2, and 3.53ppt for T0 v. T1(or T2).

Supporting Documents and Materials

IRB