162. Association Between Antibiotic Use and Multidrug-Resistant Organism Detection in Advanced Cancer Patients on Palliative Chemotherapy

Background Data suggest end-of-life antibiotics predispose to multidrug-resistant organism (MDRO) acquisition in intensive care units (ICUs). Less is known regarding antibiotics and MDRO acquisition in other palliative care populations. Methods We conducted a nested case–control study of advanced cancer patients aged ≥65 years started on palliative chemotherapy from January 2016 to September 2017 at Yale New Haven Hospital. We identified patients with (cases) and without (controls) new MDRO detected from clinical or surveillance cultures from the first hospitalization after starting palliative chemotherapy. All patients had no history of MDRO, and 3 controls were randomly selected per case. Antibiotic use was defined as exposure on or prior to the MDRO culture collection date in cases or during the entire hospitalization in controls. The association between antibiotics and MDRO detection was assessed with χ2 and multivariable logistic regression testing. Length of stay (LOS) was compared between groups. Results Of 1,181 advanced cancer patients started on palliative chemotherapy and subsequently admitted, we identified 45 cases and 135 controls (figure). Overall, median age was 75 years (range 65–95) and 48% (N = 87/180) were female. Antibiotic exposure was more likely in cases (91%, N = 41/45) vs. controls (75%, N = 101/135; P = 0.02). In regression testing adjusted for gender, LOS, and ICU stay, antibiotic use was associated with MDRO detection (OR = 3.23, 95% CI 1.1, 9.8; P = 0.04). Mean LOS was higher in those with (8.7 days, 95% CI 7.5, 10.0) vs. without (3.5 days, 95% CI 3.8, 6.1) MDRO detection (P = 0.002) Conclusion In older advanced cancer patients on palliative chemotherapy, antibiotic use is predictive of new MDRO detection, and patients with new MDRO detection have significantly longer LOS. These results suggest antibiotics should be used cautiously in palliative care patients in whom the burdens of MDRO detection, such as longer LOS and potential room isolation with contact precautions, may conflict with goals of care.Table: Predictors of MDRO detection in advanced cancer patients ≥65 years on palliative chemotherapy Predictor OR (95% CI) P value Female gender 1.1 (0.6, 2.3) 0.71 LOS ≥ 3 days 3.5 (0.8, 16.0) 0.10 ICU stay 1.3 (0.5, 3.5) 0.63 Antibiotic use 3.2 (1.1, 9.8) 0.04 Disclosures M. Juthani-Mehta, Iterum Therapeutics: Scientific Advisor, Consulting fee.