The 2nd Edition of this popular book emphasizes patient and community protection, illustrates the correct use of statistics in health care research for healthcare workers and adds considerable new and updated information. The new edition smooths the statistics learning curve for health care researchers, further de-emphasizing mathematical and computational devices and bringing the principles of statistical reasoning into reach for the uninitiated. Added to updated discussions of research design, hypothesis testing, regression analysis, and Bayes procedures are new material on absolute and relative risk, plus a lucid explanation of the Number Needed to Treat (NNT). Varied and nonstandard content makes this a unique volume among introductory statistics books. New figures, discussion and illustrations fortify each chapter. In addition, three new appendices have been added on the normal distribution, sample size computations, and new requirements for the use of statistics in the courtroom.