Risk factors for carbapenemase-producing organisms among inpatients in Scotland: A national matched case-control study

Abstract

Objective: To determine risk factors for carbapenemase-producing organisms (CPOs) and to determine the prognostic impact of CPOs. Design: A retrospective matched case-control study. Patients: Inpatients across Scotland in 2010-2016 were included. Patients with a CPO were matched with 2 control groups by hospital, admission date, specimen type, and bacteria. One group comprised patients either infected or colonized with a non-CPO and the other group were general inpatients. Methods: Conditional logistic regression models were used to identify risk factors for CPO infection and colonization, respectively. Mortality rates and length of postisolation hospitalization were compared between CPO and non-CPO patients. Results: In total, 70 CPO infection cases (with 210 general inpatient controls and 121 non-CPO controls) and 34 CPO colonization cases (with 102 general inpatient controls and 60 non-CPO controls) were identified. Risk factors for CPO infection versus general inpatients were prior hospital stay (adjusted odds ratio [aOR], 4.05; 95% confidence interval [CI], 1.52-10.78; P =.005), longer hospitalization (aOR, 1.07; 95% CI, 1.04-1.10; P