Refinement in the European Union: A Systematic Review

SIMPLE SUMMARY: More than 10 years have passed since the publication of Directive 2010/63/EU on the protection of animals used for scientific purposes based on replacement, reduction, and refinement (3Rs). These principles state that if animals have to be used in experiments, researchers should make every effort to replace them with non-sentient alternatives, reduce them to a minimum, and refine experiments and housing conditions so as to cause the minimum possible pain and distress. In this systematic review, we aimed to identify and summarize published advances in the refinement protocols made by European Union-based research groups from 2011 to 2021, and to determine whether or not said research was financially supported. Our results indicated that the majority of advances were related to improvements in experimental procedures for mice, and the research groups were mostly from universities and the United Kingdom. More than two thirds of the studies received financial support, mostly national. There is a clear willingness in the scientific community to improve the welfare of laboratory animals. However, we believe that more progress in refinement would have been made during these years if there had been more specific financial support available at both the national and European Union levels. ABSTRACT: Refining experiments and housing conditions so as to cause the minimum possible pain and distress is one of the three principles (3Rs) on which Directive 2010/63/EU is based. In this systematic review, we aimed to identify and summarize published advances in the refinement protocols made by European Union-based research groups from 2011 to 2021, and to determine whether or not said research was supported by European or national grants. We included 48 articles, the majority of which were related to improvements in experimental procedures (37/77.1%) for mice (26/54.2%) and were written by research groups belonging to universities (36/57.1%) and from the United Kingdom (21/33.9%). More than two thirds (35/72.9%) of the studies received financial support, 26 (mostly British) at a national level and 8 at a European level. Our results indicated a clear willingness among the scientific community to improve the welfare of laboratory animals, as although funding was not always available or was not specifically granted for this purpose, studies were published nonetheless. However, in addition to institutional support based on legislation, more financial support is needed. We believe that more progress would have been made in refinement during these years if there had been more specific financial support available at both the national and European Union levels since our data suggest that countries investing in refinement have the greatest productivity in successfully publishing refinements.