title: The median informs the message: accuracy of individualized scenarios for survival time based on oncologists' estimates.
abstract: OBJECTIVE
  To determine the accuracy and usefulness of oncologists' estimates of survival time in individual patients with advanced cancer.
  
  
  METHODS
  Twenty-one oncologists estimated the "median survival of a group of identical patients" for each of 114 patients with advanced cancer. Accuracy was defined by the proportions of patients with an observed survival time bounded by prespecified multiples of their estimated survival time. We expected 50% to live longer (or shorter) than their oncologist's estimate (calibration), 50% to live from half to double their estimate (typical scenario), 5% to 10% to live ≤ one quarter of their estimate (worst-case scenario), and 5% to 10% to live three or more times their estimate (best-case scenario). Estimates within 0.67 to 1.33 times observed survival were deemed precise. Discriminative value was assessed with Harrell's C-statistic and prognostic significance with proportional hazards regression.
  
  
  RESULTS
  Median survival time was 11 months. Oncologists' estimates were relatively well-calibrated (61% shorter than observed), imprecise (29% from 0.67 to 1.33 times observed), and moderately discriminative (Harrell C-statistic 0.63; P = .001). The proportion of patients with an observed survival half to double their oncologist's estimate was 63%, ≤ one quarter of their oncologist's estimate was 6%, and three or more times their oncologist's estimate was 14%. Independent predictors of observed survival were oncologist's estimate (hazard ratio [HR] = 0.92; P = .004), dry mouth (HR = 5.1; P < .0001), alkaline phosphatase more than 101 U/L (HR = 2.8; P = .0002), Karnofsky performance status ≤ 70 (HR = 2.3; P = .007), prostate primary (HR = 0.23; P = .002), and steroid use (HR = 2.4; P = .02).
  
  
  CONCLUSIONS
  Oncologists' estimates of survival time were relatively well-calibrated, moderately discriminative, independently associated with observed survival, and a reasonable basis for estimating worst-case, typical, and best-case scenarios for survival.
authors.affiliation: Belinda E. Kiely, Andrew J. Martin, and Martin R. Stockler, National Health and Medical Research Council Clinical Trials Centre, University of Sydney; Belinda E. Kiely, Martin H.N. Tattersall, Nicholas R.C. Wilcken, Philip J. Beale, and Martin R. Stockler, Sydney Medical School, University of Sydney; Belinda E. Kiely, Martin H.N. Tattersall, Philip J. Beale, and Martin R. Stockler, Sydney Cancer Centre-Royal Prince Alfred and Concord Hospitals, Sydney; David Goldstein, Prince of Wales Hospital Clinical School, University of New South Wales, Kensington; Nicholas R.C. Wilcken, Westmead Hospital, Westmead; Ehtesham A. Abdi, Tweed Hospital, Tweed Heads; Amanda Glasgow, Wollongong Hospital, Wollongong, New South Wales; Anna K. Nowak, School of Medicine and Pharmacology, University of Western Australia, Crawley; Anna K. Nowak, Sir Charles Gardner Hospital, Nedlands, Western Australia; David K. Wyld, Royal Brisbane and Women's Hospital, Brisbane, Queensland; Michael Jefford, Peter MacCallum Cancer Centre; Michael Jefford, University of Melbourne, Melbourne, Victoria, Australia; and Paul A. Glare, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Belinda E
authors.initials: BE
authors.lastname: Kiely
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Martin
authors.forename: Martin H N
authors.initials: MH
authors.lastname: Tattersall
authors.forename: Anna K
authors.initials: AK
authors.lastname: Nowak
authors.forename: David
authors.initials: D
authors.lastname: Goldstein
authors.forename: Nicholas R C
authors.initials: NR
authors.lastname: Wilcken
authors.forename: David K
authors.initials: DK
authors.lastname: Wyld
authors.forename: Ehtesham A
authors.initials: EA
authors.lastname: Abdi
authors.forename: Amanda
authors.initials: A
authors.lastname: Glasgow
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Beale
authors.forename: Michael
authors.initials: M
authors.lastname: Jefford
authors.forename: Paul A
authors.initials: PA
authors.lastname: Glare
authors.forename: Martin R
authors.initials: MR
authors.lastname: Stockler
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017567:Karnofsky Performance Status; D008017:Life Expectancy; D008297:Male; D008495:Medical Oncology; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D009369:Neoplasms / Q000401:mortality* / Q000628:therapy; D010819:Physician's Role; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate; D013997:Time Factors