KEYWORDS 2 beta-lactamases, extended-spectrum β-lactamase producing Enterobacteriaceae, cancer, prediction, risk stratification 3 Abstract Background: Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) infections are frequent and highly impact cancer patients. We developed and validated a scoring system to identify cancer patients harboring ESBL-PE at the National Institute of Cancer of Colombia.
Methods: We retrospectively analyzed medical records of 1695 cancer patients. Derivation phase included 710 patients admitted between 2013 to 2015, ESBL-PE positive culture (n = 265) paired by month and hospitalization room with Non-ESBL-PE (n = 445). A crude and weighted score was developed by conditional logistic regression. The model was evaluated in a Validation cohort (n = 985) with the same eligibility criteria between 2016 to 2017.Results: The score was based on eight variables (reported with Odds Ratio and 95% confidence interval): Hospitalization ≥7 days (5.39 [2.46 -11.80]), Hospitalization during the previous year (4 , 87 [2.99 -7.93]), immunosuppressive therapy during the previous 3 months (2.97 [1.44-6.08]), Neutropenia (1.90 [1.12 -3.24]), Exposure to Betalactams during previous month (1.61 [1.06 -2.42]), Invasive devices (1.51 [1.012 -2.25]), Neoplasia in remission (2.78 [1.25 -1.17]), No chemotherapy during the previous 3 months (1.90 [1.22 -2.97]). The model demonstrated an acceptable discriminatory capacity in the Derivation phase, but poor in the Validation phase (Recipient Operating Characteristic Curve: 0.68 and 0.55 respectively). Conclusions: Cancer patients have a high prevalence of risk factors for ESBL-PE infection. The scoring system did not adequately discriminate patients with ESBL-PE. In a high-risk population, other strategies should be sought to identify patients at risk of resistant ESBL-PE infection.