Organ Donation Survey Experiment

Last registered on June 01, 2021


Trial Information

General Information

Organ Donation Survey Experiment
Initial registration date
May 31, 2021

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
June 01, 2021, 10:25 AM EDT

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



Primary Investigator

Behavioural Economics Team of the Australian Government

Other Primary Investigator(s)

Additional Trial Information

Start date
End date
Secondary IDs
This study will examine the effectiveness of various behaviourally informed messages to encourage people to register as organ donors.
External Link(s)

Registration Citation

Team Registration, BETA. 2021. "Organ Donation Survey Experiment." AEA RCT Registry. June 01.
Experimental Details


Two different behaviourally informed messages (plus a control message) encouraging organ donor registration will be displayed to participants.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Registering as an organ donor on the Donate Life webform.

Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Clicked on the link to the webform signup (binary), stated likelihood of registering this week (binary, those that say they ‘definitely’ will + that they ‘just did a moment ago’ = 1)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
A three-arm survey experiment, randomised at the individual level.
Experimental Design Details
A three-arm survey experiment, randomised at the individual level.
Participants will be screened, so that only people who state that they want to be organ donors, but have not registered, will participate. They will be shown one of three different messages designed to encourage organ donation registration. They will also be presented with a link to a webform that can be used to register. It will be made clear that registration is voluntary, and that they do not need register in order to complete the survey. They will also be asked for their views on the message they were presented with.
We have three hypotheses
H1. Treatment group 1 registrations > Control group registrations
H2. Treatment group 2 registrations > Control group registrations
H3. Treatment group 1 registrations ≠ Treatment group 2 registrations
H1 and H2 are directional hypotheses and we be tested using one-tailed tests, H3 will be tested with a two tail test. We will use same hypotheses for the secondary measures
Note that we do not propose to adjust for multiple hypothesis testing
Randomization Method
Randomisation will be at the level of individual survey participants. Individuals will be randomly assigned to the three treatment groups using complete random assignment. Assignment will be balanced (that is, an equal number in each treatment group) to the extent that the sample size allows.

Randomisation will be implemented via within the survey platform Qualtrics, with equal probabability of assignment across the three groups
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
approx 700 individuals
Sample size: planned number of observations
approx 700 individuals
Sample size (or number of clusters) by treatment arms
approx 230 individuals in each of the three trial arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We performed power calculations that indicated that at an alpha of 5% we will have 80% power to detect a standardised effect of 0.261. If we assume that the control group has a registration rate of 1%, this would be equivalent to a 4.25pp increase for treatment groups 1 or 2.

Institutional Review Boards (IRBs)

IRB Name
Macquarie University Human Research Ethics Committee
IRB Approval Date
IRB Approval Number
Analysis Plan

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Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials