title: The impact on risk-factor analysis of different mortality outcomes in COPD patients.
abstract: The aim of the present study was to analyse the role of potential selection processes and their impact when evaluating risk factors for 30-day mortality among patients hospitalised for chronic obstructive pulmonary disease (COPD). A cohort of 26,039 patients aged > or = 35 yrs and hospitalised with COPD were enrolled. A 30-day follow-up was carried out using both the cause mortality register (CMR) and the hospital discharge register (HDR). Individual and hospital factors associated with 30-day mortality were studied using both mortality outcomes. The 30-day mortality rate was 1.21.1,000 patient-days(-1) (95% confidence interval (CI) 1.14-1.29) using the CMR, and 1.06.1,000 patient-days(-1) (95% CI 0.98-1.13) using the HDR. Male patients, the most poorly educated, those who resided outside Rome and those who had more than one hospitalisation in the previous 2 yrs were more likely to die after discharge than when hospitalised. The most frequent cause of in-hospital death was respiratory disease and after discharge, heart disease. Older age, male sex, comorbidities, previous hospitalisations for respiratory failure, and admission to a ward not appropriate to treat respiratory diseases were the most important predictors of 30-day mortality. Using in-hospital 30-day mortality provides a significantly different estimate of the role of specific risk factors.
authors.affiliation: Dept of Epidemiology, LHA RME, V. S. Costanza n 53, 00198 Rome, Italy. faustini@asplazio.it
authors.forename: A
authors.initials: A
authors.lastname: Faustini
authors.forename: C
authors.initials: C
authors.lastname: Marino
authors.forename: D
authors.initials: D
authors.lastname: D'Ippoliti
authors.forename: F
authors.initials: F
authors.lastname: Forastiere
authors.forename: V
authors.initials: V
authors.lastname: Belleudi
authors.forename: C A
authors.initials: CA
authors.lastname: Perucci
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality*; D012307:Risk Factors; D015983:Selection Bias; D017678:Sex Distribution