What is it? Why is it important?

All collected study data must eventually be entered into the eCRF of the study. How data is collected (e.g. pCRF, laboratory print outs, participant questionnaire) or structured (number of visits, type of variables) depends on the set-up or design of the study.

Each participant and event (e.g. study visit) is given a unique identifier. This is important to:

  • Maintain participant confidentiality
  • Ensure any collected data is correctly allocated to the respective participant and applicable study visit
  • Monitor individual study progress (e.g. participant recruitment)
  • Build a data-set with variables that can be used for statistical analysis and the evaluation of your study


Database set-up or structure can include aspects such as:

  • The inclusion of a pre-defined number of study visits
  • A randomised study where participants are allotted to various possible treatment options
  • Blinded interventions where treatment and placebo groups are coded and not-identifiable
  • Standardised code libraries (e.g. ATC and MedDRA coding)

What do I need to do?

As SP-INV or Site-INV:

  • Delegate data entry responsibilities to qualified staff
  • Ensure staff is properly trained and have ongoing access to the eCRF of the study (e.g. individual access protected logins and passwords)
  • Ensure a study DMan is available for questions or support (e.g. access, updates, system failure)
  • Review the eCRF to confirm the accuracy of any entered data

Any data analysis performed by the SP-INV during study conduct can only be implemented based on specifications given in the study protocol (e.g. planned interim analysis).


Responsibilities of staff entering study data might include to:

  • Compile, sort and if applicable compute source-data in preparation for data entry
  • Review data for deficiencies or errors, including the correction of detected inconsistencies
  • Enter data within given time limits, as it prevents belated queries and potential errors
  • Ensure the exclusive use of personal logins. This guarantees the correct documentation of the audit trail, regarding what data was entered or changes by which staff member

Where can I get help?

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


ICH GCP E6(R2) – see in particular guidelines

  • 5.5. Trial Management, data handling, and record-keeping
  • ATC - Anatomical Therapeutic Chemical
  • CTU – Clinical Trials Unit
  • DMan – Data Manager
  • eCRF – Electronic Case Report Form
  • MedDRA – Medicinal Dictionary for Regulatory Activites
  • pCRF – Paper Case Report Form
  • Site-INV – Site Investigator
  • SP-INV – Sponsor Investigator
Conduct ↦ Data Handling ↦ Data Entry ↦ Collection

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): Conduct ↦ Data Handling ↦ Data Entry ↦ Collection

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