Statistics and evidence-based veterinary medicine: answers to 21 common statistical questions that arise from reading scientific manuscripts.

Evidence-based veterinary medicine relies critically on the scientific validity of research. A component of validity is the statistical design and subsequent analysis of data collected during the study. Correct statistical design reduces bias and improves generalizability, and correct analysis leads to appropriate inferences. Inference is the art and science of making correct decisions based on data. Because veterinarians are responsible for the medical care of their patents, it is also their responsibility to understand inferences about treatments presented in papers. This article is designed to assist veterinarians with the interpretation and understanding of statistics presented in papers.