What is it? Why is it important?

The HRA ordinances (ClinO, ClinO-MD, HRO) define three possible risk-categories, namely A, B, or C, with category A resenting a low risk and category C a high risk. Based on study type, either three, two or no category apply.



  • Based in ClinO-MD, risk-categories for Medical Device (MD) studies are either:
    • A, which are further subdivided into A1 and A2
    • C, which are further subdivided into C1, C2 and C3


What do I need to do?

As a SP-INV:

  • Select the Ordinance (e.g. ClinO, ClinO-MD or HRO) that applies to your study
  • Use the KOFAM risk-calculator to support you in defining the risk-category of your study (e.g. A has the lowest and C the highest risk)
  • If still in doubt, submit your questions to the Ethics Committee (EC) through BASEC portal. They can provide you with useful advice
  • Upon EC submission, include the defined risk-category of your study and its rational


The EC reviews the defined risk-category of your study, and can decide to change its category to a higher or lower risk level.

Where can I get help?

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

External Links

Swissethics – see in particular

  • BASEC: the portal for EC submission


KOFAM: Coordination portal for human research – see in particular 

  • Online wizard for risk categorisation

Swiss Law

ClinO – see in particular articles and annex

  • Art. 19 Categorisation of clinical trials of medicinal products
  • Art. 20 Categorisation of clinical trials of products under Article 2a paragraph 2 TPA
  • Art. 21 Categorisation of clinical trials of transplant products
  • Art. 22 Categorisation of clinical trials of gene therapy and genetically modified or pathogenic organisms
  • Art. 49 Categorisation of clinical trials of transplantation of human organs, tissues and cells
  • Art. 61 Categorisation of other clinical studies

ClinO-MD – see in particular article

  • Art. 6 Categorisation of
  • investigations

HRO – see in particular article

  • Art. 7 Categorisation

IvDO – see in particular

  • Art. 14 Classification
  • BASEC – Business Administration System for Ethics Committees
  • BM – Biological Material
  • ClinO – Clinical Trials Ordinance
  • ClinO-MD – Ordinance on Clinical Trials for Medical Devices
  • CTU – Clinical Trials Unit
  • EC – Ethics Committee
  • HRA – Human Research Act
  • HRO – Human Research Ordinance
  • HRpD – Health-Related Personal Data
  • IMD – Investigational Medical Device
  • IMP – Investigational Medicinal Product
  • IvDO – Ordinance on In Vitro Diagnostic Medical Devices
  • KOFAM – Coordination Office for Human Research
  • MD – Medical Device
  • MP – Medicinal Product
  • SP-INV – Sponsor Investigator
  • TPA – Therapeutic Products Act
Concept ↦ Ethics and Laws ↦ Study Categorisation ↦ Risk Categories

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): Concept ↦ Ethics and Laws ↦ Study Categorisation ↦ Risk Categories

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