Statistical Issues for Longevity Studies in Animal Models

In this chapter we provide an overview of basic statistical concepts and procedures that are germane to researchers interested in aging. We include discussions of hypothesis testing, research design, statistical power, data collection, statistical significance, parametric and nonparametric statistical methods, and choosing an appropriate statistical test. We also provide brief introductions to the different types of data (categorical versus continuous), summary statistics, and a selection of parametric and nonparametric statistical tests including t-tests, analysis of variance, ordinary least squares regression, logistic regression, and survival analysis. We place special emphasis on statistics for maximum lifespan using the example of animal research on caloric restriction. We also include discussions of the major methods of significance testing for statistics of maximum lifespan. We conclude the chapter by offering a series of recommendations that will greatly increase the chances of conducting a valid statistical analysis.

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