JSM 2012 Home

JSM 2012 Online Program

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

Online Program Home

Abstract Details

Activity Number: 384
Type: Topic Contributed
Date/Time: Tuesday, July 31, 2012 : 2:00 PM to 3:50 PM
Sponsor: Biopharmaceutical Section
Abstract - #305561
Title: Two Intent-to-Treat Principles
Author(s): Thomas Permutt*+
Companies: FDA
Address: 10903 New Hampshire Avenue, Silver Spring, MD, 20993, United States
Keywords: missing data ; causal inference ; intent to treat

Most statisticians think all patients should be analyzed as randomized. Some clinicians think the outcome that should be analyzed is the status of each patient at the planned endpoint, regardless of adherence to assigned treatment. The two principles agree on what to do, in some cases: follow every randomized patient to the end, and analyze as randomized. Both have been called "the intent-to-treat (ITT) principle." But sometimes they conflict. In crossover trials, for example, analyzing completers only satisfies statisticians but may raise questions for clinicians about generalizability.

Furthermore, sometimes clinicians reject the clinical ITT principle, wanting instead a measure of what happens to adherent patients. The statistician's job is to create an analysis that as nearly as possible obeys the statistical principle of comparing like to like while meeting the clinician's need for a relevant measure of outcome. Three tools are available: retrieved dropouts, utility-based composite outcomes, and causal modeling of the effect among the treated.

The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2012 program

2012 JSM Online Program Home

For information, contact jsm@amstat.org or phone (888) 231-3473.

If you have questions about the Continuing Education program, please contact the Education Department.