title: A new approach to the analysis of antibiotic resistance data from hospitals.
abstract: We aimed to develop a new approach to the analysis of antimicrobial resistance data from the hospitals, which allows simultaneous analysis of both individual- and population-level determinants of bacterial resistance. This was a retrospective cohort study that included adult patients who stayed in the hospital >2 days. We analyzed data using shared frailty Cox models and tested our approach using a priori hypotheses based on biology and epidemiology of antibiotic resistance. For gram-negative bacteria, the use of the major selecting antibiotic by an individual was the main risk factor for acquiring resistant species. Hazard ratios (HRs) were strikingly high for ceftazidime-resistant Enterobacter species (HR=11.17; 95% confidence interval [CI]: 5.67-22.02), ciprofloxacin-resistant Pseudomonas aeruginosa (HR=4.41; 95% CI: 2.14-9.08), and imipenem-resistant P. aeruginosa (HR=7.92; 95% CI: 4.35-14.43). Ward-level use was significant for vancomycin-resistant enterococci (VRE) (HR=1.40; 95% CI: 1.07-1.83) and for imipenem-resistant P. aeruginosa (HR=1.40; 95% CI: 1.08-1.83). Previous incidence of infection in the same ward increased the risk of acquiring methicillin-resistant Staphylococcus aureus (HR=1.22; 95% CI: 1.15-1.30) and VRE (HR=1.53; 95% CI: 1.38-1.70). Our results were consistent with our hypotheses and showed that combining population- and individual-level data is crucial for the exploration of antimicrobial resistance development.
authors: 1 Department of Epidemiology, Harvard School of Public Health , Boston, Massachusetts.
authors: Sibel
authors: S
authors: Ascioglu
authors: Matthew H
authors: MH
authors: Samore
authors: Marc
authors: M
authors: Lipsitch
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D002442:Ceftazidime / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D004754:Enterobacter / Q000187:drug effects / Q000302:isolation & purification; D005260:Female; D006761:Hospitals; D006801:Humans; D015378:Imipenem / Q000627:therapeutic use; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D012189:Retrospective Studies; D020713:Vancomycin Resistance / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D015378:Imipenem; D002442:Ceftazidime