An Investigation of the Attributable Outcomes of Carbapenem-Resistant Acinetobacter baumannii (CRAB) Among Hospitalized Patients with Urinary Tract Infections or Bloodstream Infections Open Access

Popkin, Daniel (Spring 2022)

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Antibiotic resistance bacteria are an increasing area of concern due to poor outcomes attributable to these infections, resulting in morbidity and mortality. Carbapenem-resistance Acinetobacter baumannii (CRAB) has been deemed an “urgent” threat by CDC due to increasing resistance to this class of antibiotics. CRAB presents an extraordinary challenge for healthcare facilities, as infected or colonized patients can spread the bacteria when appropriate infection prevention and control procedures are inadequately executed. Patients with CRAB infections are usually very ill to begin with and estimates of attributable outcomes of CRAB infections may be imprecise due to biased selection of uninfected controls with lower likelihood for poor outcomes. This study explored if individuals with CRAB experience more severe outcomes, as compared to individuals who were not infected or colonized with CRAB but were as ill or had similar underlying illness as patients with XRAB. A case-control study was performed using case reports from the Georgia Emerging Infections Program linked to hospital encounter information from the Georgia Hospital Discharge Database. Seventy-seven cases were propensity score matched using 118,000 potential controls by ICD-9/ICD-10 codes. Propensity score matching was conducted to ensure cases were being compared with individuals as likely as being infected with CRAB. Wilcoxon signed-rank tests were utilized to evaluate the differences in length of stay and time to re-admission between cases and matched controls. Length of stay, the time between a patient’s first discharge and their next subsequent readmission, or frequency of incident hospitalization death were not significantly different between matched cases and controls. These findings may represent negligible outcomes attributable to CRAB when cases are appropriately matched with individuals with similar comorbidities, or a lack of power due to small sample size. Further exploration of attributable outcomes related to CRAB with larger sample sizes should be conducted to better understand the true morbidity and mortality associated with these infections.

Table of Contents

Chapter I: Background                                                                                                                  

Chapter II: Manuscript






Chapter III: Public Health Implications                                                                                       



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