A case-control study of the clinical and economic impact of infections caused by Carbapenemase-producing Enterobacterales (CPE)

Infection. 2024 May 3. doi: 10.1007/s15010-024-02268-z. Online ahead of print.

Abstract

Purpose: The aim was to analyse the clinical and economic impact of carbapenemase-producing Enterobacterales (CPE) infections.

Methods: Case-control study. Adult patients with CPE infections were considered cases, while those with non-CPE infections were controls. Matching criteria were age (± 5 years), sex, source of infection and microorganism (ratio 1:2). Primary outcome was 30-day mortality. Secondary outcomes were 90-day mortality, clinical failure, hospitalisation costs and resource consumption.

Results: 246 patients (82 cases and 164 controls) were included. Klebsiella pneumoniae OXA-48 was the most common microorganism causing CPE infections. CPE cases had more prior comorbidities (p = 0.007), septic shock (p = 0.003), and were more likely to receive inappropriate empirical and definitive antibiotic treatment (both p < 0.001). Multivariate analysis identified septic shock and inappropriate empirical treatment as independent predictors for 7-day and end-of-treatment clinical failure, whereas Charlson Index and septic shock were associated with 30- and 90-day mortality. CPE infection was independently associated with early clinical failure (OR 2.18, 95% CI, 1.03-4.59), but not with end-of-treatment clinical failure or 30- or 90-day mortality. In terms of resource consumption, hospitalisation costs for CPE were double those of the non-CPE group. CPE cases had longer hospital stay (p < 0.001), required more long-term care facilities (p < 0.001) and outpatient parenteral antibiotic therapy (p = 0.007).

Conclusions: The CPE group was associated with worse clinical outcomes, but this was mainly due to a higher comorbidity burden, more severe illness, and more frequent inappropriate antibiotic treatment rather than resistance patterns as such. However, the CPE group consumed more healthcare resources and incurred higher costs.

Keywords: Carbapenem-Resistant Enterobacterales; Carbapenemase; Hospital costs; Mortality; Multiple drug resistance.