title: Is pathology necessary to predict mortality among men with prostate-cancer?
abstract: BACKGROUND
  Statistical models developed using administrative databases are powerful and inexpensive tools for predicting survival. Conversely, data abstraction from chart review is time-consuming and costly. Our aim was to determine the incremental value of pathological data obtained from chart abstraction in addition to information acquired from administrative databases in predicting all-cause and prostate cancer (PC)-specific mortality.
  
  
  METHODS
  We identified a cohort of men with diabetes and PC utilizing population-based data from Ontario. We used the c-statistic and net-reclassification improvement (NRI) to compare two Cox- proportional hazard models to predict all-cause and PC-specific mortality. The first model consisted of covariates from administrative databases: age, co-morbidity, year of cohort entry, socioeconomic status and rural residence. The second model included Gleason grade and cancer volume in addition to all aforementioned variables.
  
  
  RESULTS
  The cohort consisted of 4001 patients. The accuracy of the admin-data only model (c-statistic) to predict 5-year all-cause mortality was 0.7 (95% CI 0.69-0.71). For the extended model (including pathology information) it was 0.74 (95% CI 0.73-0.75). This corresponded to a change in category of predicted probability of survival among 14.8% in the NRI analysis. The accuracy of the admin-data model to predict 5-year PC specific mortality was 0.76 (95% CI 0.74-0.78). The accuracy of the extended model was 0.85 (95% CI 0.83-0.87). Corresponding to a 28% change in the NRI analysis.
  
  
  CONCLUSIONS
  Pathology chart abstraction, improved the accuracy in predicting all-cause and PC-specific mortality. The benefit is smaller for all-cause mortality, and larger for PC-specific mortality.
authors.affiliation: Division of Urology, Rabin Medical Center, Beilinson Campus, 39 Jabotinsky, Petah Tikva, 4941492, Israel. sdmargel@gmail.com.|Davidoff Cancer Center, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel. sdmargel@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Margel
authors.affiliation: Departments of Surgery and Health Policy Management and Evaluation, University of Toronto, Toronto, Canada. david.urbach@uhn.ca.|Division of Clinical Decision Making and Health Care, Toronto General Hospital Research Institute, Toronto, Canada. david.urbach@uhn.ca.|Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada. david.urbach@uhn.ca.|Cancer Care Ontario, Ontario, Canada. david.urbach@uhn.ca.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Canada. david.urbach@uhn.ca.
authors.forename: David R
authors.initials: DR
authors.lastname: Urbach
authors.affiliation: Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada. lorraine.lipscombe@wchospital.ca.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Canada. lorraine.lipscombe@wchospital.ca.|Department of Medicine, Women's College Hospital and Research Institute, University of Toronto, Toronto, Canada. lorraine.lipscombe@wchospital.ca.
authors.forename: Lorraine L
authors.initials: LL
authors.lastname: Lipscombe
authors.affiliation: Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada. cbell@mtsinai.on.ca.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Canada. cbell@mtsinai.on.ca.|Department of Medicine and Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada. cbell@mtsinai.on.ca.
authors.forename: Chaim M
authors.initials: CM
authors.lastname: Bell
authors.affiliation: Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada. Girish.Kulkarni@uhn.ca.|Division of Urology, Department of Surgical Oncology, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada. Girish.Kulkarni@uhn.ca.
authors.forename: Girish
authors.initials: G
authors.lastname: Kulkarni
authors.affiliation: Division of Urology, Rabin Medical Center, Beilinson Campus, 39 Jabotinsky, Petah Tikva, 4941492, Israel. jbaniel@clalit.org.il.
authors.forename: Jack
authors.initials: J
authors.lastname: Baniel
authors.affiliation: Division of Urology, Department of Surgical Oncology, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada. neil.fleshner@uhn.ca.
authors.forename: Neil
authors.initials: N
authors.lastname: Fleshner
authors.affiliation: Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada. peter.austin@ices.on.ca.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Canada. peter.austin@ices.on.ca.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
mesh_terms: D000368:Aged; D002423:Cause of Death; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology*; D006801:Humans; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology*; D012042:Registries; D018570:Risk Assessment / Q000379:methods