Risk factors for death in a cohort of patients with and without healthcare-associated infections in Finnish acute care hospitals

Abstract

We evaluated risk factors for death among hospitalised patients with healthcare-associated infections (HCAIs) using the McCabe classification and Charlson index to predict mortality. The study consisted of a cohort of 703 patients with HCAIs and 7531 patients without HCAI in acute care hospitals participating in the Finnish national prevalence survey in 2005. We used Centers for Disease Control and Prevention definitions for HCAIs and recorded the McCabe classification for comorbidity. We used the date from the prevalence survey and the patient's national identity code in order to retrieve data from the National Hospital Discharge Registry on discharge diagnoses (International Classification of Diseases-10 codes) for the Charlson index and the dates of death from the National Population Information System. Of all inpatients, 425 (5.2%) died within 28 days from the prevalence survey date; the death rate was higher in HCAI patients than in those without HCAI (9.8% vs 4.7%, P<0.001). In the multivariate regression analysis age >65 years, intensive care, McCabe classification and Charlson index, gastrointestinal system infection and pneumonia/other lower respiratory tract infections were independent predictors for death. The survival analysis, when adjusted by McCabe class or Charlson index, showed that HCAI reduced survival only among patients without severe underlying diseases. Certain types of HCAI increased the risk of death. The McCabe classification had advantages over the Charlson index as a predictor of death, because it was easier to collect from a prevalence survey.