Attributable mortality to healthcare-associated infections: a comprehensive nationwide assessment in Spain, 2022 and 2023

Abstract

Background: Few studies have quantified mortality caused by healthcare-associated infections (HAIs) of all types. Aim: This work’s objective was to estimate the overall impact of HAIs on mortality in Spain. Methods: Spain performs annually a point prevalence survey of HAIs and antimicrobial use in hospitalised patients. In 2022 and 2023, prospective follow-ups of patients to evaluate their status 30 days after the survey (still admitted, discharged, deceased) were additionally conducted. This information allowed assessing the effect of HAIs on mortality, by logistic regression. We calculated the attributable fraction among the exposed (patients with HAIs) and the population attributable fraction (among all hospitalised patients). Finally, we estimated the annual number of deaths attributable to HAIs. Results: Of 107,781 inpatients included in the study, 56,323 (52.26%) were males and 51,458 (47.7%) females. Most patients (n=59,790; 55.47%) were ≥ 65 years old. The HAI prevalence was 7.8% (n=8,375). Crude mortality rate was 5.7% (5,715/99,406) among patients without HAIs and 11.0% (918/8,375) among those with HAIs. The adjusted odds ratio (AOR) for inpatient mortality associated with HAIs was 1.70 (95%CI: 1.56–1.86). The attributable fraction of deaths due to HAIs among inpatients who died with a HAI was 41.2% and 3.2% among all inpatient deaths. The estimated annual number of inpatient deaths attributable to HAIs in Spain was 6,774. Conclusion: In Spain, HAIs highly impact mortality. The number of deaths attributable to HAIs is over three times that caused by road traffic accidents. Addressing this requires immediate strengthening of infection prevention programmes across healthcare settings and their thor-ough implementation.