What is it? Why is it important?

Study data is any information that is collected or generated during study conduct and which is needed to answer its primary- and secondary research questions.

Any required study data should be specified and documented in the study protocol.

For the statistical analysis only digital data can be used. Still, in studies also non-digital data formats can be collected (e.g. laboratory notebooks, participant diaries, interviews). Consequently, any non-digital data must initially be translated into some type of coded format prior to being used for statistical analysis.


Typical data to be collected in a study are:

  • Descriptive data (e.g. age, gender, demographics)
  • Information on patient consent
  • Data required to answer the primary and secondary research questions of a study (e.g. disease characteristics, efficacy data, observational data)
  • Safety data reported by study participants (e.g. experienced adverse events during study participation)

What do I need to do?

Only data needed to answer the study question should be listed in the study protocol and consequently collected during study conduct.

The excessive collection and documentation of data not needed to answer the study question:

  • Adds unnecessary burden to study participants, which is considered unethical from a participant perspective
  • Will increase the required resources needed to perform the study (e.g. infrastructure, study staff, handling and analysis of biological samples)
  • Will increase study cost and thus required funds

For more information refer to Feasibility in this Study Guide.


Health related data is considered sensitive data. Thus, special handling and management of such data is required in order to protect the identity of study participants.

Where can I get help?

Your local CTU can support you with experienced staff regarding this topic

  • CTU – Clinical Trials Unit
Basic ↦ Data Handling ↦ Study Database ↦ Study Data

Provides some background knowledge and basic definitions

Basic Protocol
Basic Statistics
Basic Monitoring
Basic Drug or Device
Basic Biobanking

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Protocol
Concept Statistics
Concept Drug or Device
Concept Biobanking

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Protocol
Development Statistics
Development Drug or Device
Development Biobanking

Starts with ethics and regulatory approval

Ends after successful study initiation

Set-Up Protocol
Set-Up Ethics and Laws
Set-Up Statistics
Set-Up Quality and Risk
Set-Up Drug or Device
Set-Up Biobanking

Starts with participant recruitment

Ends after the last participant has completed the last study visit

Conduct Protocol
Conduct Statistics
Conduct Drug or Device
Conduct Biobanking

Starts with last study visit completed

Ends after study publication and archiving

Completion Protocol
Completion Statistics
Completion Drug or Device
Completion Biobanking
Current Path (click to copy): Basic ↦ Data Handling ↦ Study Database ↦ Study Data

Please note: the Easy-GCS tool is currently under construction.