Summarizing data on survival, relapse, and chronic graft-versus-host disease after bone marrow transplantation: motivation for and description of new methods.

Kaplan-Meier curves are frequently used to summarize survival, relapse, and chronic graft-versus-host disease (GVHD) data in the bone marrow transplant setting. Some fundamental problems with the use of Kaplan-Meier curves for the summary of relapse and GVHD are described. Alternatively, the use of simple probability and conditional probability curves for summarizing relapse incidence and transplant-related mortality is illustrated with previously published data from a randomized clinical trial. Prevalence curves provide an appropriate alternative for the summary of a transient condition such as chronic GVHD. When combined with Kaplan-Meier curves for survival and/or relapse-free survival, these methods provide a more accurate and comprehensive summary of the various marrow transplant outcomes. These methods of display are also applicable to other settings where more than one type of treatment failure can occur and where follow-up time may be variable.