Understanding measures of associations, how they are calculated, what they mean, and how to compare them is an important part of understanding clinical and health research. The relative risk (RR) and odds ratio (OR) are the two most common used measures of association in medical research. The appropriate use of these statistics to estimate the association between treatment or risk factor and outcome in research studies depends on the methodology and design of the study. The aim of this article is to cover basics of odds ratio and relative risk as the most important measures for the association between an exposure and an outcome. We use a clinical scenario as an example of their uses and demonstrate their calculation.
1Associate Professor, Department of Medicine, McMaster University
2Clinical Epidemiologist and Knowledge Translation Officer, Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto
3Associate Professor, Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto
Corresponding author: Dinesh Kumbhare, MD, PhD, FRCPC, FAAPMR, 550 University Avenue, Suite 7-131, Toronto, Ontario M5G 2A2, firstname.lastname@example.org, Telephone: 416-597-3422 x 4612
Author Disclosures: All the authors report no conflict of interest for the completion of this manuscript. Also, no funding was received.