Experimental Design: Reduction and Refinement in Studies Using Animals

摘要: Abstract In animal studies, good experimental design achieves the research objectives with minimal numbers and severity. Key elements are clear objectives, controls that allow unambiguous interpretation, avoidance of bias by proper randomization appropriate blinding. Experimental units (often not individual animals), which can be independently assigned to different groups planned, need correctly identified, a power analysis or resource equation estimate indicates how many (replicates) use. Numbers needed less if effect detected increased using best measure, more sensitive subjects, well-informed selection species strain. Marked reduction achieved reducing controlling sources variation, for example, subjects free from infection genetically uniform designs increase precision, such as randomized block within-subject comparisons. Factorial designs, in include animals sexes, ages, strains, so forth, variation due these factors analyzed distinguished variability main effect, generality findings, statistical testing whether subgroups respond differently, providing information without increasing numbers. Severity minimized least severe procedures sequence procedures, setting humane endpoints, and, experiments, review points starting lower severity studies.