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Study phases

The implementation of each clinical trial entails the following phases:

Idea and requirement analysis

The idea for a study often arises from the dissatisfaction of the attending doctors with regard to the options or devices currently available. The respective clinical problem is analysed on the basis of the study idea. This analysis is based, on the one hand, on the experience of the doctors and, on the other hand, on the problems described in the literature.

Study planning and approval

In this step, the structure, implementation, research question and objective of the study are planned in detail. This involves defining a number of elements, including which and how many patients are to be included in the study (inclusion and exclusion criteria).

In addition, study-specific tests and the way in which these tests are to be performed are defined and the risk-benefit ratio of the study is evaluated.

Before a clinical trial may be implemented, it must be approved by an ethics committee and, depending on the risk category of the study, it will also need to be approved by the relevant authorities. The study will only begin after these bodies have given their approval.

Recruitment and data acquisition prior to treatment

As soon as approval has been granted, patients are recruited for the study and given comprehensive information about it. Once the participants have issued their consent to the study in writing, specific tests to obtain data prior to the treatment are started in accordance with the approved study documents.

Data acquisition following treatment

The data is obtained again following the treatment – this takes place at clearly defined test times. Depending on the study, treatment can entail an operation, injection or therapy programme, for example.

Data analysis

As soon as all the data is acquired for all the patients included in the study, the analysis of the data obtained before and after treatment starts. Important scientific questions can finally be answered with the results.


There is a legal obligation to publish the results of clinical trials transparently in national and international registries and/or in scientific journals and thereby make the results available to the public.

Research projects at the Schulthess Klinik

You can find information on our ongoing studies and completed studies by entering “Schulthess Clinic” in the keyword search in the kofam national registry ( or in the international registries ( and the WHO International Clinical Trials Registry Platform (

Schulthess Klinik

Schulthess Klinik
Lengghalde 2
8008 Zürich

Teaching, Research and Development