title: Risk stratification for death and all-cause hospitalization in heart failure clinic outpatients.
abstract: BACKGROUND
  Most heart failure (HF) risk stratification models were developed for inpatient use, and available outpatient models use a complex set of variables. We hypothesized that routinely collected clinical data could predict the 6-month risk of death and all-cause medical hospitalization in HF clinic outpatients.
  
  
  RESULTS
  Using a quality improvement database and multivariable Cox modeling, we derived the Heart Failure Patient Severity Index (HFPSI) in the University of Michigan HF clinic (UM cohort, n = 1,536; 314 reached primary outcome). We externally validated the HFPSI in the Ann Arbor Veterans' Affairs HF clinic (VA cohort, n = 445; 106 outcomes) and explored "real-time" HFPSI use (VA-RT cohort, n = 486; 141 outcomes) by tracking VA patients for 6 months from their most recently calculated HFPSI, rather than using an arbitrary start date for the cohort. The HFPSI model included blood urea nitrogen, B-type natriuretic peptide, New York Heart Association class, diabetes status, history of atrial fibrillation/flutter, and all-cause hospitalization within the prior 1 and 2 to 6 months. The concordance c statistics in the UM/VA/VA-RT cohorts were 0.71/0.68/0.74. Kaplan-Meier curves and log-rank testing demonstrated excellent risk stratification, particularly between a large, low-risk group (40% of patients, 6-month event rates in the UM/VA/VA-RT cohorts 8%/12%/12%) and a small, high-risk group (10% of patients, 6-month event rates in the UM/VA/VA-RT cohorts 57%/58%/79%).
  
  
  CONCLUSIONS
  The HFPSI uses readily available data to predict the 6-month risk of death and/or all-cause medical hospitalization in HF clinic outpatients and could potentially help allocate specialized HF resources within health systems.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI; Ann Arbor Veterans' Affairs Medical Center, Ann Arbor, MI. Electronic address: scothumm@med.umich.edu.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Hummel
authors.forename: Hussam H
authors.initials: HH
authors.lastname: Ghalib
authors.forename: David
authors.initials: D
authors.lastname: Ratz
authors.forename: Todd M
authors.initials: TM
authors.lastname: Koelling
mesh_terms: D000368:Aged; D005260:Female; D006333:Heart Failure / Q000401:mortality*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate