Measures of Association

Contents

Page 1
Introduction
Learning Objectives

Page 2
Comparing Risk Among Two or More Exposure Groups
Data Summary
Two by Two Tables (2x2) or Contingency Tables
Options for Comparing Disease Frequencies

Page 3
Risk Ratios and Rate Ratios (Relative Risk)
Risk Ratio
Risk Ratio < 1
Percent Relative Effect
Rate Ratios

Page 4
Multiple Exposure Groups: Using a Reference Group

Page 5
Risk Differences and Rate Differences
Risk Differences
Tips For Interpreting Risk Difference
Rate Differences
Perspective of Relative Differences (Ratios) vs. Absolute Differences

Page 6
Attributable Proportion
Attributable Proportion Among the Exposed
The "Preventive Fraction"

Page 7
The Population Attributable Fraction

Page 8
Measuring Association in Case-Control Studies
The Odds Ratio
Odds Ratio as an Estimate of Risk Ratio
Incidence is Unknown in a Case-Control Study
Attributable Proportion Among the Exposed in Case-Control Studies
Population Attributable Fraction (PAF) in a Case-Control Study

Content ©2016. All Rights Reserved.
Date last modified: February 17, 2016.
Wayne W. LaMorte, MD, PhD, MPH

Boston University School of Public Health