title: External validation of the Hospital-patient One-year Mortality Risk (HOMR) model for predicting death within 1 year after hospital admission.
abstract: BACKGROUND
  Predicting long-term survival after admission to hospital is helpful for clinical, administrative and research purposes. The Hospital-patient One-year Mortality Risk (HOMR) model was derived and internally validated to predict the risk of death within 1 year after admission. We conducted an external validation of the model in a large multicentre study.
  
  
  METHODS
  We used administrative data for all nonpsychiatric admissions of adult patients to hospitals in the provinces of Ontario (2003-2010) and Alberta (2011-2012), and to the Brigham and Women's Hospital in Boston (2010-2012) to calculate each patient's HOMR score at admission. The HOMR score is based on a set of parameters that captures patient demographics, health burden and severity of acute illness. We determined patient status (alive or dead) 1 year after admission using population-based registries.
  
  
  RESULTS
  The 3 validation cohorts (n = 2,862,996 in Ontario, 210 595 in Alberta and 66,683 in Boston) were distinct from each other and from the derivation cohort. The overall risk of death within 1 year after admission was 8.7% (95% confidence interval [CI] 8.7% to 8.8%). The HOMR score was strongly and significantly associated with risk of death in all populations and was highly discriminative, with a C statistic ranging from 0.89 (95% CI 0.87 to 0.91) to 0.92 (95% CI 0.91 to 0.92). Observed and expected outcome risks were similar (median absolute difference in percent dying in 1 yr 0.3%, interquartile range 0.05%-2.5%).
  
  
  CONCLUSIONS
  The HOMR score, calculated using routinely collected administrative data, accurately predicted the risk of death among adult patients within 1 year after admission to hospital for nonpsychiatric indications. Similar performance was seen when the score was used in geographically and temporally diverse populations. The HOMR model can be used for risk adjustment in analyses of health administrative data to predict long-term survival among hospital patients.
authors.affiliation: Departments of Medicine and of Epidemiology and Community Medicine, University of Ottawa (van Walraven), Ottawa, Ont.; Ottawa Hospital Research Institute (van Walraven, Hawken), Ottawa, Ont.; Department of Medicine, University of Alberta, and Alberta Innovates - Health Solutions (McAlister), Edmonton, Alta.; Health Research Methods and Analytics, Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, and Alberta Strategy for Patient Oriented Research Support Unit (Bakal), Edmonton, Alta.; Division of General Internal Medicine, Bern University, Bern, Switzerland; Brigham & Women's Hospital and Harvard Medical School (Donzé), Boston, Mass. carlv@ohri.ca.
authors.forename: Carl
authors.initials: C
authors.lastname: van Walraven
authors.affiliation: Departments of Medicine and of Epidemiology and Community Medicine, University of Ottawa (van Walraven), Ottawa, Ont.; Ottawa Hospital Research Institute (van Walraven, Hawken), Ottawa, Ont.; Department of Medicine, University of Alberta, and Alberta Innovates - Health Solutions (McAlister), Edmonton, Alta.; Health Research Methods and Analytics, Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, and Alberta Strategy for Patient Oriented Research Support Unit (Bakal), Edmonton, Alta.; Division of General Internal Medicine, Bern University, Bern, Switzerland; Brigham & Women's Hospital and Harvard Medical School (Donzé), Boston, Mass.
authors.forename: Finlay A
authors.initials: FA
authors.lastname: McAlister
authors.affiliation: Departments of Medicine and of Epidemiology and Community Medicine, University of Ottawa (van Walraven), Ottawa, Ont.; Ottawa Hospital Research Institute (van Walraven, Hawken), Ottawa, Ont.; Department of Medicine, University of Alberta, and Alberta Innovates - Health Solutions (McAlister), Edmonton, Alta.; Health Research Methods and Analytics, Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, and Alberta Strategy for Patient Oriented Research Support Unit (Bakal), Edmonton, Alta.; Division of General Internal Medicine, Bern University, Bern, Switzerland; Brigham & Women's Hospital and Harvard Medical School (Donzé), Boston, Mass.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Bakal
authors.affiliation: Departments of Medicine and of Epidemiology and Community Medicine, University of Ottawa (van Walraven), Ottawa, Ont.; Ottawa Hospital Research Institute (van Walraven, Hawken), Ottawa, Ont.; Department of Medicine, University of Alberta, and Alberta Innovates - Health Solutions (McAlister), Edmonton, Alta.; Health Research Methods and Analytics, Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, and Alberta Strategy for Patient Oriented Research Support Unit (Bakal), Edmonton, Alta.; Division of General Internal Medicine, Bern University, Bern, Switzerland; Brigham & Women's Hospital and Harvard Medical School (Donzé), Boston, Mass.
authors.forename: Steven
authors.initials: S
authors.lastname: Hawken
authors.affiliation: Departments of Medicine and of Epidemiology and Community Medicine, University of Ottawa (van Walraven), Ottawa, Ont.; Ottawa Hospital Research Institute (van Walraven, Hawken), Ottawa, Ont.; Department of Medicine, University of Alberta, and Alberta Innovates - Health Solutions (McAlister), Edmonton, Alta.; Health Research Methods and Analytics, Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, and Alberta Strategy for Patient Oriented Research Support Unit (Bakal), Edmonton, Alta.; Division of General Internal Medicine, Bern University, Bern, Switzerland; Brigham & Women's Hospital and Harvard Medical School (Donzé), Boston, Mass.
authors.forename: Jacques
authors.initials: J
authors.lastname: Donzé
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000416:Alberta; D001900:Boston; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006760:Hospitalization; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009026:Mortality; D009864:Ontario; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D055815:Young Adult