# Biostatistics For Dummies

Authors:

## Overview

Break down biostatistics, make sense of complex concepts, and pass your class

If you're taking biostatistics, you may need or want a little extra assistance as you make your way through. Biostatistics For Dummies follows a typical biostatistics course at the college level, helping you understand even the most difficult concepts, so you can get the grade you need. Start at the beginning by learning how to read and understand mathematical equations and conduct clinical research. Then, use your knowledge to analyze and graph your data. This new edition includes more example problems with step-by-step

walkthroughs on how to use statistical software to analyze large datasets. Biostatistics For Dummies is your go-to guide for making sense of it all.
• Review basic statistics and decode mathematical equations
• Learn how to analyze and graph data from clinical research studies
• Look for relationships with correlation and regression
• Use software to properly analyze large datasets

Anyone studying in clinical science, public health, pharmaceutical sciences, chemistry, and epidemiology-related fields will want this book to get through that biostatistics course.

Biostatistics For Dummies Cheat Sheet

To estimate sample size in biostatistics, you must state the effect size of importance, or the effect size worth knowing about. If the true effect size is less than the “important” size, you don’t care if the test comes out nonsignificant. With a few shortcuts, you can pick an important effect size and find out how many participants you need, based on that effect size, for several common statistical tests. All the graphs, tables, and rules of thumb here are for 80 percent power and α = 0.05. In other words, the guidance applies to calculating sample size you need in order to have an 80 percent chance of getting a p value that’s less than or equal to 0.05. If you want sample sizes for other values of power and α, use these simple scale-up rules:

• For 90 percent power instead of 80 percent: Increase N by a third (multiply N by 1.33).
• For α = 0.01 instead of 0.05: Increase N by a half (multiply N by 1.5).
• For 90 percent power and α = 0.01: Double N (multiply N by 2).