What is it? Why is it important?

An Adverse Event (AE) is an untoward medical occurrence, unintended disease or injury, or any untoward clinical signs (e.g. abnormal laboratory finding) that occurs within the context of a clinical investigation, whether or not related to the IMD in:

  • A study participant
  • A user of the IMD
  • Some other person


An Adverse Device Effect (ADE) is an AE assessed as being related, with a causal or reasonably possible relationship, to the use of:

  • The Investigational Medical Device (IMD) under investigation, or
  • The MD used as a comparator (e.g. a licensed MD used as a reference in the study), or
  • Investigational study procedures (e.g. MD set-up)

What do I need to do?

As a Site-INV perform a safety assessment, which includes the assessment of:

  • Severity (e.g. grading of intensity)
  • Causality, by determining whether the AE is an ADE (e.g. definitively, probably, possibly related)
  • Seriousness, by deciding whether the AE or ADE is a serious event. If defined as serious, follow required SAE / SADE reporting procedures


Based on the Clinical Investigation Plan (CIP), investigate and document all non-serious AEs and ADEs in the:

  • Source Document (SDs) (e.g. participant original medical records during and after study conduct)
  • Study database / CDMS (eCRF)


Documentation starts once the participant has signed the ICF until:

  • The study is finished for the participant, or
  • The end of some predefined safety follow-up period (e.g. as defined in the CIP)


A CIP documents the rationale, objectives, design, methodology, monitoring, safety, conduct, and planned statistical analysis of a study with Medical Device.

Where can I get help?

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

External Links

Swissmedic – see in particular information sheet

  • MU680_20_004e_MB Medical devices FAQs Patients


ISO 14155:2020 Medical device (access liable to cost) – see in particular sections

  • 3.1 ADE definition
  • 3.2 AE definition

MDCG 2020-10/1– see in particular guidelines

  • 3.2 AE definition
  • 9. Causality Assessment

MDR 2017-745 – see in particular articles

  • Art. 2 (57) AE definition
  • Art. 80 (1) Recording and reporting of AE that occur during clinical investigations

Swiss Law

ClinO-MD – see in particular article

  • Art. 32 Documentation of AE


  • AE – Adverse Event
  • ADE – Adverse Device Effect
  • CDMS – Clinical Data Management System
  • CIP – Clinical Investigation Plan
  • ClinO-MD – Ordinance on Clinical Trials with Medical Devices
  • CTU – Clinical Trials Unit
  • eCRF – electronic Case Report Form
  • FAQ – Frequently Asked Questions
  • ICF – Informed Consent Form
  • IMD – Investigational Medicinal Device
  • ISO - International Organization for Standardization
  • MD – Medical Device
  • MDCG – Medical Device Coordination Group
  • MDR – Medical Device Regulation
  • SADE – Serious Adverse Device Effect
  • SAE – Serious Adverse Event
  • SD – Source Document
  • Site-INV – Site Investigator
Conduct ↦ Safety ↦ Medical Device Safety Reporting ↦ Adverse Event / Adverse Device Effect

Provides some background knowledge and basic definitions

Basic Protocol
Basic Statistics
Basic Monitoring
Basic Drug or Device

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Protocol
Concept Statistics
Concept Drug or Device

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Protocol
Development Statistics
Development Drug or Device

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

Starts with participant recruitment

Ends after the last participant has completed the last study visit

Conduct Protocol
Conduct Statistics
Conduct Drug or Device

Starts with last study visit completed

Ends after study publication and archiving

Completion Protocol
Completion Statistics
Completion Drug or Device
Current Path (click to copy): Conduct ↦ Safety ↦ Medical Device Safety Reporting ↦ Adverse Event / Adverse Device Effect

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