JSM 2004 - Toronto

Abstract #301301

This is the preliminary program for the 2004 Joint Statistical Meetings in Toronto, Canada. Currently included in this program is the "technical" program, schedule of invited, topic contributed, regular contributed and poster sessions; Continuing Education courses (August 7-10, 2004); and Committee and Business Meetings. This on-line program will be updated frequently to reflect the most current revisions.

To View the Program:
You may choose to view all activities of the program or just parts of it at any one time. All activities are arranged by date and time.

The views expressed here are those of the individual authors
and not necessarily those of the ASA or its board, officers, or staff.

Back to main JSM 2004 Program page
Activity Number: 156
Type: Contributed
Date/Time: Monday, August 9, 2004 : 2:00 PM to 3:50 PM
Sponsor: Biopharmaceutical Section
Abstract - #301301
Title: Comparison of Methods of Missing-data Imputation in Analysis of Two Phase III Trials Treating HIV1 Infection
Author(s): Les Huson*+ and Jain Chung and Miklos Salgo
Companies: F. Hoffman La Roche and F. Hoffman La Roche and F. Hoffman La Roche
Address: Broadwater Way, Welwyn, International, , United Kingdom
Keywords: missing data ; imputation ; HIV1
Abstract:

In most longitudinal clinical trials, some patients drop out before the end of the planned follow-up, and, in order to allow an all-patient intent-to-treat analysis to be performed, it is common practice to use some method of imputation to estimate values for missing data. However, different imputation methods may give different results, and it is essential to investigate the sensitivity of the analysis using different imputation rules. Trials of treatment for HIV1 infection involve measurement of HIV1-RNA plasma values over time, and change from baseline in HIV1-RNA plasma concentration is a key measure of success. In our analysis of two trials of the new HIV1 fusion inhibitor enfuvirtide, we compared several methods of imputing and analyzing HIV1-RNA data, to check the robustness of the primary endpoint results. These were: (1) multiple imputation, (2) a nearest-neighbor hot-deck method, (3) censored regression analysis using last-observation-carried-forward, (4) last-observation-carried-forward using analysis of covariance, and (5) zero change from baseline (baseline-carried-forward).

  • 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 2004 program

JSM 2004 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.
Revised March 2004