Centre of Evidence Based Dermatology

Cochrane Skin Core Outcomes Set Initiative (CSG-COUSIN) 


"Our mission is to develop and implement core outcomes sets in dermatology in order to improve and standardize outcome measurement in clinical trials and to make trial evidence more useful."

The Cochrane Skin Outcomes Set Initiative (CSG-COUSIN) is a working group within Cochrane Skin founded by Jochen Schmitt and Hywel Williams in 2014. 

CSG-COUSIN is open to everyone with an interest in outcomes research and evidence-based dermatology who is interested in the development and implementation of Core Outcome Sets in dermatology.

The collaborative initiative is co-ordinated from Center for Evidence-Based Healthcare, University of Dresden, Germany.

More information is available below, and from the main CSG-COUSIN website.


Why do we need CSG-COUSIN?

Cochrane plays a critical role in summarising and translating research knowledge into clinical practice. The choice of adequate outcome measures in clinical trials is essential to make trials meaningful and valid. The failure to assess the outcome domains most important to patients and the continued use of outcome measurement instruments with unclear validity and reliability are frequent and important barriers towards evidence-based medicine.

The second barrier in evidence-based clinical decision making in dermatology is the use of many different outcome measures in clinical trials on a specific skin condition, which makes it almost impossible to compare the studies or include them in a meta-analysis.

Aims and Structure

The over-arching goal of CSG-COUSIN is to develop standardized, evidence-based and consensus derived disease specific core outcome sets in dermatology for inclusion in all trials. Through the development and implementation of core outcome sets, we aim to improve trials and to make trial information more useful for patients, health care professionals and policy makers. 

What is a core outcome set?

A core outcome set (COS) is a standardized, consented, minimum set of outcome measurement instruments to be used in every trial in a particular medical field. A core outcome set does not mean that only the COS should be measured, but simply that the COS should be measured in all future trials of that particular skin disease, so that results can be compared properly. Outcomes that are additional to the COS can be measured as required by the specific study.

How to develop core outcome sets in dermatology?

The development of a COS requires an integrated process of systematic reviews, consensus studies, validation studies, and structured consensus voting.

First, outcome domains need to be agreed. Domains refer to what is being measured (e.g. quality of life, disability, or survival). Then, one adequate measurement instrument has to be identified for each core outcome domain. To be adequate a measurement instrument needs to be valid, reliable and feasible. Once one measurement instrument has been selected for each core outcome domain, the final core set of outcome measurement instruments is complete.

To structure and guide the COS development process, our group has developed a roadmap with our colleagues from the international and multi-professional Harmonizing Outcome Measures for Eczema (HOME) initiative. 


If you are interested in getting involved, or just finding out more about CSG-COUSIN, please contact:

Jochen Schmitt
Center for Evidence-Based Healthcare
Technische Universität Dresden
Universitätsklinikum Carl Gustav Carus
Fetscherstraße 74
D- 01307 Dresden
Telephone: +49 (0) 351 458 6497
Fax: +49 (0) 351 458 7238 

Core Outcome Set links

Condition specific groups:

Other information about core outcome sets is available from the COMET and COSMIN initiatives.

Centre of Evidence Based Dermatology

The University of Nottingham
Applied Health Research Building
University Park, Nottingham

telephone: +44 (0) 115 84 68631
email: cebd@nottingham.ac.uk