The use of systematic reviews and reporting guidelines to advance the implementation of the 3Rs.

In 1959, Russell and Burch published The Principles of Humane Experimental Technique, which included concrete advice on factors that they considered would govern progress in the implementation of these principles (enunciated as the 3Rs [Replacement, Reduction, and Refinement in animal-based studies]). One challenge to the implementation of the 3Rs was identified as information retrieval. Here, we further explore this challenge-the need for 'research on research'-and the role that systematic reviews and reporting guidelines can play in implementation of the 3Rs. First, we examine the 2-fold nature of the challenge of information retrieval: 1) the identification of relevant publications spread throughout a large population of nonrelevant publications and 2) the incomplete reporting of relevant details within those publications. Second, we evaluate how systematic reviews and reporting guidelines can be used generally to address this challenge. Third, we assess the explicit reporting of the 3Rs in a cohort of preclinical animal systematic reviews. Our results show that Reduction methods are the most commonly reported by authors of systematic reviews but that, in general, reporting on how findings relate to the 3Rs is limited at best. Although systematic reviews are excellent tools for resolving the challenge of information retrieval, their utility for making progress in implementation of the 3Rs may be limited unless authors improve their reporting of these principles.