Table 1_Prediction of vancomycin-resistant phenotype in ICU-onset sterile-site Enterococcus-positive cultures: development and pseudo-temporal validation of a clinical prediction model using MIMIC-IV.docx

During the interval between organism identification and final phenotypic antimicrobial susceptibility testing, clinicians must balance delayed effective anti-VRE therapy against unnecessary anti-VRE exposure. We aimed to develop and pseudo-temporally validate a model for the vancomycin-resistance phenotype of the index isolate; the model does not determine whether the isolate represents clinically significant infection.</p>Methods<p>In this retrospective MIMIC-IV cohort, adult ICU admissions with a sterile-site Enterococcus-positive culture obtained more than 48 hours after ICU admission were assigned by de-identified anchor-year group to development (groups labelled 2008–2016; n = 552) or pseudo-temporal validation (2017–2022; n = 259).

Predictors were restricted to information available by specimen collection. Elastic Net with bootstrap stability screening retained 19 of 141 candidates; four tree-based models were comparators.</p>Results<p>Among 811 admissions (507 resistant isolates; prevalence, 62.5%), Elastic Net achieved a validation AUROC of 0.835 (95% CI, 0.778–0.889) and calibration slope of 0.91 (0.71–1.18). Tree-model AUROCs were 0.842–0.855; non-significant pairwise DeLong tests were evidence insufficient to detect differences, not evidence of equivalence.