title: Hospital comparisons based on mortality: revisiting the choice of postadmission timeframe and evaluating the contribution of cause-of-death data, France, 2009.
abstract: BACKGROUND
  In-hospital mortality is widely used to judge the quality of hospital care, but is biased by discharge patterns. Fixed-timeframe indicators have thus been recommended. However, the 30-day postadmission indicator may underestimate hospital-wide mortality, as patients dying in hospital >30 days after admission are considered as survivors.
  
  
  OBJECTIVE
  To identify the most relevant timeframes and to assess the contribution of cause-of-death data.
  
  
  METHODS
  The 2009 French hospital discharge database was linked to vital status records and to the causes of death register for 11.5 million hospital stays by beneficiaries of French general health insurance. Correlations and agreements between the 30-day hospital standardized mortality ratio (HSMR) and the in-hospital, 60-, 90-, 180-, and 365-day postadmission HSMRs were estimated.
  
  
  RESULTS
  A total of 7.8%, 1.5%, and 0.5% of patients who died during their hospital stay were considered as survivors by the 30-, 60-, and 90-day HSMRs, respectively. The 30-day HSMR correlated strongly with the 60-day HSMR (Pearson coefficient=0.92), and their agreement on outlier status was excellent (κ coefficient=0.80). The association remained substantial at 90 days, but weakened at 180 days and even more so at 365 days. Regardless of the timeframe, exclusion of deaths likely due to independent causes barely modified the indicators.
  
  
  CONCLUSIONS
  This nationwide study shows that 60- and 90-day HSMRs encompass in-hospital deaths better than the 30-day HSMR, while capturing the same interhospital variations. They should thus be preferred. The contribution of cause-of-death data to hospital-wide indicators seems negligible.
authors.affiliation: *CépiDc (Epidemiology center on medical causes of death) †UMRS 1018, Inserm ‡Faculty of Medicine Paris Sud, Université Paris Sud, Kremlin-Bicêtre §Haute Autorité de santé (HAS), Saint-Denis La Plaine ∥AP-HP, CHU Bicêtre, Service de Santé Publique et d'Epidémiologie, Kremlin-Bicêtre, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Lamarche-Vadel
authors.forename: Marcus
authors.initials: M
authors.lastname: Ngantcha
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Le Pogam
authors.forename: Walid
authors.initials: W
authors.lastname: Ghosn
authors.forename: Catherine
authors.initials: C
authors.lastname: Grenier
authors.forename: Laurence
authors.initials: L
authors.lastname: Meyer
authors.forename: Grégoire
authors.initials: G
authors.lastname: Rey
mesh_terms: D002423:Cause of Death; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data; D005602:France / Q000453:epidemiology; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D010343:Patient Admission / Q000706:statistics & numerical data*; D010351:Patient Discharge / Q000706:statistics & numerical data*; D019984:Quality Indicators, Health Care