Assessing Disease Progression Using a Composite Endpoint

• Activity Number: 101
• Type: Topic Contributed
• Date/Time: Monday, August 9, 2004 : 10:30 AM to 12:20 PM
• Sponsor: WNAR
• Author(s): Weng Kee Wong*+ and Philip J. Clements and Jim Streisand and Dan E. Furst
• Companies: University of California, Los Angeles and University of California, Los Angeles and Genzyme Corporation and University of California, Los Angeles
• Keywords: multiple outcomes ; Kaplan Meier ; Scleroderma ; chronic disease

Abstract

We investigate the usefulness of using a composite "time-to-event" analysis to evaluate disease progression in 134 patients with diffuse cutaneous Scleroderma. All patients had 18 months or less of disease duration at study entry and followed for 24 months. The composite time-to-event analysis requires a composite endpoint with a Kaplan-Meier-type analysis. Serious medical events across several organ systems would make up the composite index and we consider the endpoint is attained if a patient reaches any one of the endpoints within the composite. For example, one may define the endpoint is attained if a patient experienced any one of the following in a given time period: (i) persistent high skin score, (ii) drop in predicted DLCO by 15%, or (iii) renal involvement or (iv) heart involvement. In addition, we present results on our sensitivity analysis where one or more of the organ involvement definition criteria are adjusted and the outcomes reanalyzed. One key finding is that the usefulness of such composite endpoint depends crucially on the choice of the individual endpoints and the sensitivity of that measure.