What is it? Why is it important?

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


  • Risk categories of ClinO studies are based on the use of:
    • Drugs (MP) = A, B, C
    • IMP/IMD in combination = A, B, C
    • Standardized transplants = A, C
    • Gene therapy, genetically modified or pathogenic organisms = A, B, C
    • Transplantation = A, C
    • Ionising radiation = B,C
    • Other clinical studies = A, B


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


  • Risk categories of HRO research projects depend on the inclusion of:
    • Patients or healthy volunteers = A, B
    • Reuse of health-related personal data (HRpD) = none
    • Reuse of biological material (BM): = none
    • Deceased persons = none
    • Foetuses and embryos = none

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 of your study (e.g. A has the lowest risk and C the highest risk)
  • If still in doubt, submit your questions to the EC through BASEC portal. They can provide you with useful advice
  • Upon EC submission, include the selected risk category of your study


The risk category for your study will be review and approve by EC. If required, the EC will adapt the risk category of your study.

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 – see in particular

  • Online wizard for risk categorisation

Swiss Law

FEDLEX – laws are available online under numbers

  • 810.305 ClinO
  • 810.306 ClinO-MD
  • 810.301 HRO

ClinO – see in particular articles and annex

  • Art. 19 Categorisation of medicinal products
  • Art. 20 Categorisation of in vitro diagnostic MD and products
  • Art. 21 Categorisation of transplant products
  • Art. 22 Categorisation of gene therapy and genetically modified or pathogenic organisms
  • Art. 49 Categorisation of transplantation of human organs, tissues and cells
  • Art. 61 Categorisation of other clinical studies
  • Annex 1 International classification of diseases

ClinO-MD – see in particular article

  • Art. 6 Categorisation of clinical trials

HRO – see in particular article

  • Art. 7 Categorisation
  • 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
  • FEDLEX – Publication Platform for Federal Law
  • HRA – Human Research Act
  • HRO – Human Research Ordinance
  • HRpD – Health-Related Personal Data
  • IMD – Investigational Medical Device
  • IMP – Investigational Medicinal Product
  • KOFAM – Coordination Office for Human Research
  • MD – Medical Device
  • MP – Medicinal Product
  • SP-INV – Sponsor Investigator
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
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): Concept ↦ Ethics and Laws ↦ Study Categorisation ↦ Risk Categories

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