A new graphic for quality adjusted life years (Q-TWiST) survival analysis: The Q-TWiST plot

Academic Article


  • One of the challenges of interpreting a Quality-adjusted time without symptoms of disease and toxicity (Q-TWiST) analysis is examining the sensitivity of conclusions that may be drawn to varying values of the utility coefficients for days with toxicity and days after disease progression. We present a graphic that parsimoniously displays the impact on median Q-TWiST survival across treatment groups of varying values of the utility coefficients. The goal of the graphic is to present a concise Q-TWiST analysis. We use Zhao and Tsiatis (Biometrika 1997; 84(2): 339-348) to adjust for the bias in Kaplan-Meier (K-M) estimates. The graphic contains bounds that approximate points for which statistical significance would be achieved by comparing the median Q-TWiST survival between treatment alternatives for each value of the utility coefficients. The plot may be generalized to compare Q-TWiST means, medians or percentiles across treatment groups. We demonstrate the application of the Q-TWiST plot through a re-analysis of a randomized phase III North Central Cancer Treatment Group (NCCTG) clinical trial of recombinant Interferon-2α in patients with malignant melanoma. We explore alternative options to customize the graphic representation for other data sets drawn from several NCCTG clinical trials.
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    Digital Object Identifier (doi)

    Author List

  • Sloan JA; Sargent DJ; Lindman J; Allmer C; Vargas-Chanes D; Creagan ET; Bonner JA; O'Connell MJ; Dalton RJ; Rowland KM
  • Start Page

  • 37
  • End Page

  • 45
  • Volume

  • 11
  • Issue

  • 1