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Conditional Survival: A Useful Concept to Provide Information on How Prognosis Evolves over Time.

  • Hieke S Institute for Medical Biometry and Statistics, Medical Center, University of Freiburg, Freiburg im Breisgau, Germany.
  • Kleber M Department of Medicine I, Hematology, Oncology and Stem Cell Transplantation, Medical Center, University of Freiburg, Freiburg im Breisgau, Germany. Clinic for Internal Medicine, University Hospital Basel, Basel, Switzerland.
  • König C Department of Medicine I, Hematology, Oncology and Stem Cell Transplantation, Medical Center, University of Freiburg, Freiburg im Breisgau, Germany.
  • Engelhardt M Department of Medicine I, Hematology, Oncology and Stem Cell Transplantation, Medical Center, University of Freiburg, Freiburg im Breisgau, Germany.
  • Schumacher M Institute for Medical Biometry and Statistics, Medical Center, University of Freiburg, Freiburg im Breisgau, Germany. ms@imbi.uni-freiburg.de.
  • 2015-04-03
Published in:
  • Clinical cancer research : an official journal of the American Association for Cancer Research. - 2015
Aged
Effect Modifier, Epidemiologic
Female
Humans
Kaplan-Meier Estimate
Male
Middle Aged
Multiple Myeloma
Proportional Hazards Models
English Conditional survival (CS) is defined as the probability of surviving further t years, given that a patient has already survived s years after the diagnosis of a chronic disease. It is the simplest form of a dynamic prediction in which other events in the course of the disease or biomarker values measured up to time s can be incorporated. CS has attracted attention in recent years either in an absolute or relative form where the latter is based on a comparison with an age-adjusted normal population being highly relevant from a public health perspective. In its absolute form, CS constitutes the quantity of major interest in a clinical context. Given a clinical cohort of patients with a particular type of cancer, absolute CS can be estimated by conditional Kaplan-Meier estimates in strata defined, for example, by age and disease stage or by a conditional version of the Cox and other regression models for time-to-event data. CS can be displayed as a function of the prediction time s in parametric as well as nonparametric fashion. We illustrate the use of absolute CS in a large clinical cohort of patients with multiple myeloma. For investigating CS, it is necessary to ensure almost complete long-term follow-up of the patients enrolled in the clinical cohort and to consider potential age-stage migration as well as changing treatment modalities over time. CS provides valuable and relevant information on how prognosis develops over time. It also serves as a starting point for identifying factors related to long-term survival.
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  • English
Open access status
bronze
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https://sonar.ch/global/documents/270054
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