title: Antibiotic resistance in hospitals: a ward-specific random effect model in a low antibiotic consumption environment.
abstract: Association between previous antibiotic use and emergence of antibiotic resistance has been reported for several microorganisms. The relationship has been extensively studied, and although the causes of antibiotic resistance are multi-factorial, clear evidence of antibiotic use as a major risk factor exists. Most studies are carried out in countries with high consumption of antibiotics and corresponding high levels of antibiotic resistance, and currently, little is known whether and at what level the associations are detectable in a low antibiotic consumption environment. We conduct an ecological, retrospective study aimed at determining the impact of antibiotic consumption on antibiotic-resistant Pseudomonas aeruginosa in three hospitals in Norway, a country with low levels of antibiotic use. We construct a sophisticated statistical model to capture such low signals. To reduce noise, we conduct our study at hospital ward level. We propose a random effect Poisson or binomial regression model, with a reparametrisation that allows us to reduce the number of parameters. Inference is likelihood based. Through scenario simulation, we study the potential effects of reduced or increased antibiotic use. Results clearly indicate that the effects of consumption on resistance are present under conditions with relatively low use of antibiotic agents. This strengthens the recommendation on prudent use of antibiotics, even when consumption is relatively low.
authors.affiliation: The Norwegian Computing Center, 0314 Oslo, Norway. Magne.Aldrin@nr.no
authors.forename: Magne
authors.initials: M
authors.lastname: Aldrin
authors.forename: Ragnhild
authors.initials: R
authors.lastname: Raastad
authors.forename: Ingunn Fride
authors.initials: IF
authors.lastname: Tvete
authors.forename: Dag
authors.initials: D
authors.lastname: Berild
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Frigessi
authors.forename: Truls
authors.initials: T
authors.lastname: Leegaard
authors.forename: Dominique L
authors.initials: DL
authors.lastname: Monnet
authors.forename: Mette
authors.initials: M
authors.lastname: Walberg
authors.forename: Fredrik
authors.initials: F
authors.lastname: Müller
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003198:Computer Simulation; D024881:Drug Resistance, Bacterial; D006761:Hospitals; D006801:Humans; D015233:Models, Statistical; D009664:Norway / Q000453:epidemiology; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents