title: Heart failure hospitalization: An important prognostic factor for heart failure re-admission and mortality.
abstract: BACKGROUND
  Few studies have evaluated incidence rates and risk factors for heart failure hospitalization (HFH) and mortality starting at initial heart failure (HF) diagnosis.
  
  
  METHODS
  Patients with a first ever recorded diagnosis of HF between January 2000 and December 2005 (N=3516) were identified from The Health Improvement Network primary care database and followed until April 2011 to identify HFHs (through linked hospitalization data) and deaths. HF patients were stratified by hospitalization status at HF diagnosis (start date), and hazard ratios (HRs) for HFH and death were estimated using Cox regression. Predictors of HF re-admission were identified by nested case-control analysis among patients hospitalized at start date, using patients with a new HFH during follow-up as cases and a set of age and sex matched controls.
  
  
  RESULTS
  During a mean follow-up of 4.5years, 32% of incident HF patients (n=1119) had a HFH and 58.5% died (n=2056). Compared with patients not hospitalized at initial HF diagnosis (N=2759), a two-fold increased risk of HFH during follow-up, consistent over time, was seen in patients hospitalized at initial HF diagnosis (N=757); adjusted HR 2.14 (95% CI: (1.88-2.44). Major predictors of HFH were renal impairment, diabetes and prior HFH. Mortality rates were higher in HF patients hospitalized at initial HF diagnosis, but the major determinant of mortality was HFH during follow-up: HR 3.88 (95% CI: 3.53-4.26) irrespective of HFH status at initial diagnosis.
  
  
  CONCLUSIONS
  Patients hospitalized at initial HF diagnosis or with a HFH thereafter are at high risk of worse outcomes.
authors.affiliation: Spanish Centre for Pharmacoepidemiological Research (CEIFE), Madrid, Spain. Electronic address: aruigomezs@gmail.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Ruigómez
authors.affiliation: Global Epidemiology, Bayer Pharma AG, Berlin, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Michel
authors.affiliation: Spanish Centre for Pharmacoepidemiological Research (CEIFE), Madrid, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Martín-Pérez
authors.affiliation: Spanish Centre for Pharmacoepidemiological Research (CEIFE), Madrid, Spain.
authors.forename: Luis A
authors.initials: LA
authors.lastname: García Rodríguez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality*; D006760:Hospitalization / Q000639:trends; D006801:Humans; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D010359:Patient Readmission / Q000639:trends*; D011159:Population Surveillance / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies
keywords: Epidemiology; Heart failure; Hospitalization; Mortality; Risk factors