Nudging in clinical trial registration

Last registered on June 14, 2023


Trial Information

General Information

Nudging in clinical trial registration
Initial registration date
May 25, 2023

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 06, 2023, 9:15 AM EDT

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

Last updated
June 14, 2023, 2:45 AM EDT

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



Primary Investigator

BfArM Federal Institute for Drugs and Medical Device

Other Primary Investigator(s)

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The aim of this field experiment is to test whether study registrants in the German Clinical Trials Register can be nudged to complete their registration.
The greatest effort for the study registrant, but also for the registry staff, arises during the initial application for registration. Afterwards, usually only a few queries have to be processed in order to complete the registration in the registry.
In this experiment, these entries are identified and randomised into 3 groups. 2 groups receive emails with a selected nudges. 1 group serves as a control.
The primary objective is whether the study will be registered within 6 weeks of the nudge.
Secondary objectives are
- Feedback from the study managers (Mail or Phone)
- Changes to the study entry
- Deletion of the study entry
- Login from the study managers
External Link(s)

Registration Citation

Bieselt, Lisa. 2023. "Nudging in clinical trial registration." AEA RCT Registry. June 14.
Experimental Details


E-Mails with selected Nudges
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Number of study entries registered by end of intervention
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
- feedback from the study managers
- Changes to the study entry
- Deletion of the study entry
- Login form the study managers
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Study entries will be randomly assigned to one of three groups. The study managers of the entries in the first 2 groups will receive an e-mail with a selected nudge. 1 group serves as a control.
Experimental Design Details
Randomization Method
Stratified randomization: Three groups are formed, depending on the last change (6 to 12 month, 12 to 18 month, more than 18 month ) to the entry. Within the groups block randomization done in office via excel
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
250 Nudge A Mail
250 Nudge B Mail
250 Controlgroup (no Mail)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


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