What are systematic reviews and research synthesis?


A systematic review refers to the entire process of collecting, reviewing and presenting all available evidence. The process is a methodological tool that researchers use in a science called research synthesis. Research synthesis is a relatively new science that aims to assemble evidence about the benefits and harms of a variety of medical and social interventions using explicit, scientifically defensible methods (systematic reviews). The aim of this process, in contrast to traditional approaches to assessing research evidence, is to minimise bias, and to seek and appraise research studies in a systematic and standard way. The process aims to make the best estimate of the "truth" about what works and what is harmful, and highlights gaps in knowledge.'


Home Office Immigration and Nationality Directorate, 2002. Refugee integration: Can research synthesis inform policy? Feasibility study report Yongmi Schibel, Mina Fazel, Reive Robb and Paul Garner. London: Home Office



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Evidence from animal research is considered by researchers to be of the lowest quality in medical research. It is therefore placed at the bottom of the hierarchy on the 'quality of evidence' pyramid because it is equivalent to 'expert opinion' or 'background information', which may or may not translate higher up the scale of evidence. The best information is currently considered to be from well conducted systematic reviews and meta-analyses.  



Research has found that scientific standards for conducting and evaluating animal research are lower than those set for clinical research and while this situation is allowed to continue patients and research volunteers are put at risk, funding wasted and better treatments not sought.  


The charity is calling for registration of all animal trials and improvements in their experimental design and in the way the research is approved, reported, published and evaluated. These measures will help to reduce bias in animal research which is subject to similar types of bias seen in clinical research but on a far greater scale. All animal studies, including primary studies, can and should be carried out and evaluated using the best available research methodologies.


The research community considers the systematic review (SR) the most appropriate method of evaluating almost any research and animal research is no exception. But there are too few systematic reviews of animal trials and the reviews are only as good as the quality and availability of the results of the research under review. This is why the charity concludes that the 10Rs+ recommendations are necessary.




Large scale programme of systematic reviews


A large-scale programme of systematic reviews of all existing animal studies is called for in order that the value of animal research to human medicine can be determined and to reduce the avoidable waste of funding unnecessary research. The publication of the results of such reviews will assist the transparency and accountability of animal research and help to improve the safety and efficacy of medical research. It will also provide much needed evidence of whether and if animal experiments translate to human (clinical) research.  


SRs will also help to direct funding more cost effectively to where it is most required and of most relevance.  In addition to SRs other research is needed to help understand why treatments found positive in animal models do not predict the same in patients and whether research may have been abandoned in the drug discovery process because no benefits were found in the animal studies.


Systematic reviews of animal studies are essential so that:


> the value of animal research to human health can be determined

> research volunteers and patients are protected from unsound research

> shareholders can escape unprofitable investments

> expensive, unnecessary and unproductive laboratory animal research can be avoided

> medical research can progress faster more reliably, safely and effectively


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Questioning the reliability of animal research for human health.

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