Missed opportunities for antibiotic de-escalation among clinically stable adult patients with bloodstream infection: secondary analysis of a prospective, multicenter study

Objectives: Antibiotic de-escalation (ADE) is a key antimicrobial stewardship (AMS) quality indicator. We aimed to evaluate the rate and patterns of ADE among clinically stable patients with bloodstream infection (BSI). Methods: We analyzed secondary data from two prospective multicenter cohort studies, BLOOMY and BLOOMY-PREDICT. ADE was assessed among patients eligible for safe ADE on day 5 after index blood culture. Narrowing of antibiotic spectrum was determined by a ranking based on WHO AWaRe-classification. Risk factors for not performing ADE (non-ADE) were studied using multivariable logistic regression. Results: In total, 937 of 3824 study patients (24.50%) were eligible, of which 218 (23.27%) did not have an option for de-escalation based on antimicrobial susceptibility testing. Of 719 patients in which ADE was feasible, only 406 (56.47%) received ADE. Empiric monotherapy (OR (95% CI) = 5.68 (3.77-8.56), p<0.001), Gram-negative pathogen (OR 2.27 (1.60-3.24), p<0.001), healthcare-associated infection (OR 1.55 (1.01-2.39), p=0.046), and hospital-acquisition (OR 1.63 (1.02-2.61), p=0.042) were identified as independent factors associated with non-ADE. Conversely, ICU treatment on day 0 (OR 0.60 (0.38-0.95), p=0.029) was independently associated with de-escalation, alongside a strong study center effect (OR 0.26 (0.15-0.44), p<0.001). Further, in-hospital mortality was not associated with ADE (46/406, 11.33% vs. 29/313, 9.27%, p=0.369). Low ADE rates in patients with urogenital focus and unnecessary carbapenem use were issues of particular concern in our cohort. Conclusions: Available opportunities for ADE were frequently missed in our setting, especially in Gram-negative BSI. AMS efforts should therefore be strengthened to promote ADE.