title: Features of hospitalisations for acute exacerbation of COPD resulting in death.
abstract: BACKGROUND
  Hospitalisation periods for the acute exacerbation phase of COPD are a strain on health facilities and entail high rates of hospital mortality. The aim of this study was to ascertain the characteristics of treatment periods resulting in death and the risk factors involved on the basis of treatment registers and death certificates.
  
  
  METHODS
  Data on all treatment periods for persons over 44 years of age with a principal diagnosis of COPD that began as emergency admissions applying to the period 1993-2001 was gathered from the hospital treatment register maintained by the Finnish National Research and Development Centre for Welfare and Health, yielding a total of 72 896 cases. Data on the deaths of the patients concerned was then obtained from Statistics Finland and those treatment periods which could be shown to have ended in death (N = 2331) were taken to form the material for analysis. These were compared with a same number of control hospitalisation periods (not ending in death) in terms of specialisation, type and geographical location of the hospital, length of the treatment period and the occurrence of subsidiary diagnoses. Attention was also paid to the season of the year and the days of the week on which admission and death took place.
  
  
  RESULTS
  The proportion of emergency admissions that ended in death was 3.2%, The patients concerned having a mean age of 74.5 years for men and 75.0 years for women on admission. The mean duration of the treatment period was 11.5 days (SD 14.8), compared with 8.0 days (SD 7.9) for the controls. A subsidiary diagnosis existed in the case of 53.6% of the periods ending in death and 37.5% of the control periods. Deaths were most frequent on Fridays, 15.6%, and least so on Tuesdays, 13.0%. Where 24.2% of patients admitted on Saturdays or Sundays died during the first 24 hours, the figure for those admitted on weekdays was only 17.7%. Altogether 62.8% of the treatment periods ending in death took place between December and May.
  
  
  CONCLUSIONS
  The COPD patients admitted at weekends showed the poorest survival, while concurrent diseases and protraction of the treatment period in winter and early spring increased the risk of death. Recognition of risk cases on admission could enable mortality to be reduced and allow savings in terms of costs through the intensification of treatment in these cases.
authors.affiliation: Ostrobothnia Hospital District, Mariankatu 16-20, FIN-67200 Kokkola, Finland. tuija.kinnunen@pp.kpnet.fi
authors.forename: T
authors.initials: T
authors.lastname: Kinnunen
authors.forename: O
authors.initials: O
authors.lastname: Säynäjäkangas
authors.forename: T
authors.initials: T
authors.lastname: Keistinen
mesh_terms: D000208:Acute Disease; D000368:Aged; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D003644:Death Certificates; D004636:Emergency Service, Hospital; D005260:Female; D005387:Finland / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality* / Q000628:therapy*; D012307:Risk Factors; D012621:Seasons; D016019:Survival Analysis; D013997:Time Factors