Semi-parametric models of long- and short-term survival: an application to the analysis of breast cancer survival in Utah by age and stage

Authors

  • A. Tsodikov

    Corresponding author
    1. Huntsman Cancer Institute at the University of Utah, Division of Biostatistics, 2000 Circle of Hope, Salt Lake City, Utah 84112-5550, U.S.A.
    • HCI, Rm 4243, 2000 Circle of Hope, Salt Lake City, Utah 84112-5550, U.S.A.
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Abstract

A flexible class of semi-parametric survival models is proposed that takes account of long- and short-term covariate effects in cancer survival. The diversity of responses described by the models include non-proportional and crossing survival curves as well as a fraction of long-term survivors. Restricted non-parametric maximum likelihood estimation procedures (RNPMLE) are developed to provide point estimates, confidence intervals and tests for the models. Numerical algorithms to fit semi-parametric survival models are emphasized. The methods are applied to analyse post-treatment survival of breast cancer patients diagnosed in Utah by age and stage. Copyright © 2002 John Wiley & Sons, Ltd.

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