Geographical variation in therapy for bloodstream infections due to multidrug-resistant Enterobacteriaceae: a post-hoc analysis of the INCREMENT study

We describe regional differences in therapy for bloodstream infection (BSI) caused by extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) or carbapenemase-producing Enterobacteriaceae (CPE). Patients (n = 1482) in 12 countries from an observational study of BSI caused by ESBL-E or CPE were included. Multivariate logistic regression was used to calculate adjusted odds ratios (aORs) for the influence of country of recruitment on empirical use of β-lactam/β-lactamase inhibitors (BLBLIs) or carbapenems, targeted use of BLBLIs for ESBL-E and use of targeted combination therapy for CPE. Compared with Spain, BLBLI use for empirical therapy was least likely in sites from Israel (aOR 0.34, 95% CI 0.14-0.81), Greece (aOR 0.49, 95% CI 0.26-0.94) and Canada (aOR 0.31, 95% CI 0.11-0.88) but more likely in Italy (aOR 1.58, 95% CI 1.11-2.25) and Turkey (aOR 2.09, 95% CI 1.14-3.81). Empirical carbapenem use was more likely in sites from Taiwan (aOR 1.73, 95% CI 1.03-2.92) and USA (aOR 1.89, 95% CI 1.05-3.39) and less likely in Italy (aOR 0.44, 95% CI 0.28-0.69) and Canada (aOR 0.10, 95% CI 0.01-0.74). Targeted BLBLIs for ESBL-E was more likely in Italian sites. Treatment at sites within Israel, Taiwan, Turkey and Brazil was associated with less combination therapy for CPE. Although this study does not provide precise data on the relative prevalence of ESBL-E or CPE, significant variation in therapy exists across countries even after adjustment for patient factors. Better understanding of what influences therapeutic choices for these infections will aid antimicrobial stewardship efforts.