Prof. Merel Ritskes-Hoitinga PhD full professor


Prof. Merel Ritskes-Hoitinga PhD
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Merel Ritskes-Hoitinga full professor

Professor Ritskes-Hoitinga's research focuses on systematic reviews (SR) and meta-analysis (MA) of animal studies.

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Merel Ritskes-Hoitinga full professor

Professor Ritskes-Hoitinga's research focuses on systematic reviews (SR) and meta-analysis (MA) of animal studies. SRs and MAs of preclinical studies promote the evidence-based choice of animal models, improve the implementation of the 3Rs (Refinement, Reduction and Replacement), stimulate scientific quality and increase patient safety. When performing SRs of preclinical animal studies next to clinical studies, better translational transparency will be created. Her group develops and publishes tools and guidelines for making this methodology more broadly available, and these tools and guidelines are also incorporated in the teaching programs of SYRCLE (see The Ministry of Economic Affairs (EZ) and the Dutch Health Foundation ZonMW have funded the development of tools, guidelines and teaching programs.

After graduating as a veterinarian, Merel became a laboratory animal scientist with the goal to improve scientific quality and welfare of laboratory animals simultaneously. After one year in Japan, doing biomedical research, she did a PhD on Refinement at Utrecht University and was trained to become Animal Welfare Officer. From 1990 to 1996 she worked at the Unilever Research laboratory, as the head of the animal unit and as Animal Welfare Officer. From 1996-2005 she was professor in Laboratory Animal Science and head of the Biomedical Laboratory of the University of Southern Denmark in Odense. Since 2005 she is professor in Laboratory Animal Science and head of the Centraal  Dierenlaboratorium (CDL) at the Radboud University Medical Centre. In 2006, Merel founded the 3R Research Centre. This was later transformed into SYRCLE, the SYstematic Review Centre for Laboratory animal Experimentation.

Systematic reviews Research subgroup

Headed by Merel Ritskes, the research group Systematic reviews aims to increase the value and reduce the waste of research in animal studies.

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Systematic reviews Research subgroup

Animal models help to gain insights in human diseases and possibilities for succesful clinical trails. By using systematic reviews, conducted research still appears to be very useful for this.

Q1 What is the aim of Systematic reviews?

“The group Systematic reviews summarizes already available evidence from conducted animal studies in order to increase the value and reduce the waste of research. First, we try to find all available information regarding a certain topic. Then, we make a critical appraisal of the research quality. This is called a meta-analysis. In the end, we make summaries of all available data. In doing so, we come to new conclusions and insights and we are able to identify gaps in knowledge, and give insight into the potential translation of research data for humans.”

Q2 What is the importance of the group?

Learn by constructing effectivenesses
“We attempt to make a transparent overview of available literature, evaluate the quality of these publications and present whether studies are reproducible or not. In this way, we can construct the effectiveness (for example, costs vs. quality and translation) of animal studies.”

Q3 How do other researchers benefit from this contribution?

“We can indentify animal models and summarize evidence from animal studies in order to gain insights in human diseases and possibilities for successful clinical trials. Thereby, we can secure efficacy and safety for human patients. Making a summary of all available knowledge regarding a topic prevents unnecessary duplication of research. Moreover, all available evidence is evaluated and allocated with a quality score. This quality assessment is important as it is based on methodological requirements, for instance, the use of randomization and blinding which are the basic starting points of our scientific practice.”

Q4 Can you give an insight in the review process?

“First, you start with a research question. After that, respectively, you search for literature, select relevant references, select relevant full text articles, extract relevant data, asses study quality, and – if possible – statistically analyze all data together (meta-analysis).”

Q5 What are goals for the future?

“The group Systematic reviews for animal studies arose from SYRCLE, a center that promotes the concept of systematic reviews of animal studies. The group is relatively new and unknown. Therefore, it is interesting to constantly make the methodology more appealing and to improve the quality of our tools. We also find that much executed research is insufficient. Researchers need to be enforced to follow drafted reporting guidelines. In 2020, the EU will evaluate the new legislation. I have suggested to the EU to designate that year as ‘the year of the systematic reviews’.”

Merel Ritskes-Hoitinga
Merel Ritskes-Hoitinga is head of Systematic reviews. Within her career as a researcher, she often relies on Zen meditation. The accompanying techniques enable her to create different points of view, break with research routines and eventually tread new paths.

Personal prizes & awards national & international

  • 2010: Price by SGV (Swiss Association for Laboratory Animal Science) for the Gold Standard Publication Checklist, as best publication in Laboratory animal science
  • 2011: Lef in't Lab prijs, Dierenbescherming (Dutch Organisation for the Protection for Animal Welfare)

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Field of study

Central Animal Laboratory

Personal links

SYstematic Review Center for Laboratory animal Experimentation SYRCLE

SYRCLE’s aim is to promote the concept of systematic reviews of animal studies (SRs) in research.

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Radboud Institute for Health Sciences

Ideally, every procedure in clinical practice and public health should take place based on proof, instead of intuition or 'experience'. Our aim is to improve clinical practice and public health.

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