A Guide to Sample Size for Animal-based Studies

A Guide to Sample Size for Animal-based Studies Understand a foundational area of experimental design with this innovative reference Animal-based research is an essential part of basic and preclinical research, but poses a unique set of experimental design challenges. The most important of these are the 3Rs − Replacement, Reduction and Refinement − the principles comprising the ethical framework for humane animal-based studies. However, many researchers have difficulty navigating the design trade-offs necessary to simultaneously minimize animal use, and produce scientific information that is both rigorous and reliable. A Guide to Sample Size for Animal-based Studies meets this need with a thorough, accessible reference work to the subject. This book provides a straightforward systematic approach to “rightsizing” animal-based experiments, with sample size estimates based on the fundamentals of statistical thinking: structured research questions, variation control and appropriate design of experiments. The result is a much-needed guide to planning animal-based experiments to ensure scientifically valid and reliable results. This book offers: Step-by-step guidance in diverse methods for approximating and refining sample size Detailed treatment of research topics specific to animal-based research, including pilot, feasibility and proof-of-concept studies Sample size approximation methods for different types of data − binary, continuous, ordinal, time to event − and different study types − description, comparison, nested designs, reference interval construction and dose-response studies Numerous worked examples, using real data from published papers, together with SAS and R code A Guide to Sample Size for Animal-based Studies is a must-have reference for preclinical and veterinary researchers, as well as ethical oversight committees and policymakers.

Table of Contents:
Preface Acknowledgements Part I. What is sample size? 1. Introduction: The sample size problem in animal-based research 2.  Sample size basics 3.  Ten strategies to increase information (and reduce animal numbers) Part II. Sample size for feasibility and pilot studies 4. Introduction to pilot studies 5. Operational pilots 6. Empirical and translational pilots 7. Feasibility calculations: Arithmetic estimation 8. Feasibility calculations: Probability-based estimation Part III. Sample size for description 9. Introduction to descriptive studies 10. Confidence intervals 11. Prediction intervals 12. Tolerance intervals 13. Reference intervals Part IV. Sample size for comparison 14. Hypothesis testing, power, non-centrality 15. A bestiary of effect sizes 16. Comparing two groups: Continuous outcomes 17. Comparing two groups: Binary and count outcomes 18. Comparing two groups: Time to event outcomes 19. Comparing multiple factors 20. Multi-level and hierarchical designs 21. Ordinal data 22. Dose-response studies Index

About the Author :
Penny S. Reynolds, PhD, is a Research Assistant Professor in the Department of Anesthesiology, College of Medicine, and Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, USA.