title: A new graphic for quality adjusted life years (Q-TWiST) survival analysis: the Q-TWiST plot.
abstract: 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-2alpha in patients with malignant melanoma. We explore alternative options to customize the graphic representation for other data sets drawn from several NCCTG clinical trials.
authors: Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA. jsloan@mayo.edu
authors: Jeff A
authors: JA
authors: Sloan
authors: Daniel J
authors: DJ
authors: Sargent
authors: Jed
authors: J
authors: Lindman
authors: Cristine
authors: C
authors: Allmer
authors: Delfino
authors: D
authors: Vargas-Chanes
authors: Edward T
authors: ET
authors: Creagan
authors: James A
authors: JA
authors: Bonner
authors: Michael J
authors: MJ
authors: O'Connell
authors: Robert J
authors: RJ
authors: Dalton
authors: Kendrith M
authors: KM
authors: Rowland
authors: Burke J
authors: BJ
authors: Brooks
authors: John A
authors: JA
authors: Laurie
mesh_terms: D003196:Computer Graphics; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D008545:Melanoma / Q000188:drug therapy* / Q000401:mortality; D019057:Quality-Adjusted Life Years; D011994:Recombinant Proteins; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000401:mortality; D016019:Survival Analysis
chemical_list: D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins