Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Multiple Comparison Procedures

Multiple Comparison Procedures Clinical Review & Education JAMA Guide to Statistics and Methods Jing Cao, PhD; Song Zhang, PhD Problems can arise when researchers try to assess the statistical 0.95 × 0.95, or 90%. With 20 such tests, the probability that all of significance of more than 1 test in a study. In a single test, statistical the20testscorrectlyshowinsignificanceis(0.95) or36%.Sothere significance is often determined based on an observed effect or find- is a 100% − 36%, or 64%, chance of at least 1 false-positive test oc- ing that is unlikely (<5%) to occur due to chance alone. When more curring among the 20 tests. Because this probability quantifies the than 1 comparison is made, the chance of falsely detecting a non- risk of making any false-positive inference by a group, or family, of existent effect increases. This is known as the problem of multiple tests, it is referred to as the family-wise error rate (FWER). The comparisons (MCs), and adjustments can be made in statistical test- FWER generally increases as the number of tests performed in- ing to account for this. creases. For example, assuming IER = 5% and denoting the number In this issue of JAMA, Saitz et al report results of http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png JAMA American Medical Association

Multiple Comparison Procedures

JAMA , Volume 312 (5) – Aug 6, 2014

Loading next page...
 
/lp/american-medical-association/multiple-comparison-procedures-x5nqlvpQkJ

References (6)

Publisher
American Medical Association
Copyright
Copyright 2014 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.
ISSN
0098-7484
eISSN
1538-3598
DOI
10.1001/jama.2014.9440
pmid
25096694
Publisher site
See Article on Publisher Site

Abstract

Clinical Review & Education JAMA Guide to Statistics and Methods Jing Cao, PhD; Song Zhang, PhD Problems can arise when researchers try to assess the statistical 0.95 × 0.95, or 90%. With 20 such tests, the probability that all of significance of more than 1 test in a study. In a single test, statistical the20testscorrectlyshowinsignificanceis(0.95) or36%.Sothere significance is often determined based on an observed effect or find- is a 100% − 36%, or 64%, chance of at least 1 false-positive test oc- ing that is unlikely (<5%) to occur due to chance alone. When more curring among the 20 tests. Because this probability quantifies the than 1 comparison is made, the chance of falsely detecting a non- risk of making any false-positive inference by a group, or family, of existent effect increases. This is known as the problem of multiple tests, it is referred to as the family-wise error rate (FWER). The comparisons (MCs), and adjustments can be made in statistical test- FWER generally increases as the number of tests performed in- ing to account for this. creases. For example, assuming IER = 5% and denoting the number In this issue of JAMA, Saitz et al report results of

Journal

JAMAAmerican Medical Association

Published: Aug 6, 2014

There are no references for this article.