What is it? Why is it important?

The protocol is the core document that describes the background, rationale, objective(s), design, statistical method, and safety aspects of a study.


The study protocol lays down “the rules” of the study. The SP-INV, trial statistician, including Site-INV(s) in a multicentre study approve the study protocol.


Prior to implementation, the study protocol must be submitted for approval to:

  • FOPH for studies on transplantation of human organs, tissues and cells (risk-category C). Studies with radiation sources that exceed 5 mSv per year for participants (risk-category C)


Once approved, the SP-INV of the study, potential partner(s), study staff, including Site-INV(s) of participating study sites are all required to comply with its specifications.


Changes to a study protocol during study conduct require a protocol amendment, followed by EC and if applicable regulatory approval prior to implementation.


In addition to specifications given in the study protocol, researchers must comply with:

What do I need to do?

Based on the study type (e.g. ClinO, ClinO-MD, Other Clinical studies, non-clinical HRO studies), different protocol requirements exist. Accordingly, swissethics provides different protocol templates on its website.


As a SP-INV, select the protocol template applicable to your planes study.

  • If unsure what templates to use clarify with EC
  • Consult experts able to support you with the write-up of your study protocol (e.g. experienced study staff, statistician responsible for the statistical part of your study, request a protocol review from a local CTU)
  • In order to ensure document tracking, establish a document management system from the very start. This will guarantee document identification starting with the first protocol draft of the study.


It is advisable to invest sufficient time in the development of the study protocol. A well thought through protocol will avoid unnecessary amendments as well as unexpected difficulties due to protocol inconsistencies during study conduct


For the development of the study protocol:

  • Analyse the particular medical/public health problem of interest, and include a review of current existing knowledge
  • Define study question(s) that can be answered statistically
  • Evaluate the impact study findings would have on public health (i.e. how will findings contribute to disease prevention, and/or contribute to any health improvements of your target population)
  • Decide on an appropriate study design. Abstain from the selection of unnecessary complex designs that only increase required resources and total study costs
  • Define what variables are needed for the evaluation of your study (i.e. outcome and predictor variables including confounding variables)


Define required statistical power, and calculate the required sample size (i.e. the required number of participants needed for 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

  • Broad selection of protocol templates


ICH GCP E6(R2) – see in particular guidelines

  • 1.44 Protocol definition
  • 1.45 Protocol amendment definition
  • 6 Clinical trial protocol and protocol amendment(s)


ISO 14155:2020 Medical devices (access liable to costs) - see in particular sections

  • 6.4 Clinical Investigational Plan (CIP)
  • Annex A CIP


Declaration of Helsinki – see in particular principles

  • 21 – 22 Protocol requirements

Swiss Law

ClinO – see in particular articles

  • Art. 19, 20, 49, and 61 Categorisation
  • Art. 29 Changes

HRO – see in particular article

  • Art. 7 Categorisation
  • Art. 18 Changes
  • ClinO – Clinical Trials Ordinance
  • ClinO-MD – Ordinance on Clinical Trials with Medical Devices
  • CTU – Clinical Trials Unit
  • EC – Ethic Committee
  • HRA – Human Research Act
  • HRO – Human research Ordinance
  • ICH GCP – International Council for Harmonisation - Good Clinical Practice
  • ISO – International Organisation for Standardisation
  • Site-INV – Site Investigator
  • SP-INV – Sponsor-Investigator
Development ↦ Management ↦ Study Documents ↦ Protocol

Provides some background knowledge and basic definitions

Basic Monitoring
Basic Drug or Device

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Drug or Device

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Drug or Device

Starts with ethics and regulatory approval

Ends after successful study initiation

Set-Up Ethics and Laws
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 Drug or Device

Starts with last study visit completed

Ends after study publication and archiving

Completion Statistics
Completion Drug or Device
Current Path (click to copy): Development ↦ Management ↦ Study Documents ↦ Protocol

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