title: Variability in Antibiotic Use Across Nursing Homes and the Risk of Antibiotic-Related Adverse Outcomes for Individual Residents.
abstract: OBJECTIVE
  Antibiotics are frequently and often inappropriately prescribed to patients in nursing homes. These antibiotics pose direct risks to recipients and indirect risks to others residing in the home.
  
  
  OBJECTIVE
  To examine whether living in a nursing home with high antibiotic use is associated with an increased risk of antibiotic-related adverse outcomes for individual residents.
  
  
  METHODS
  In this longitudinal open-cohort study performed from January 1, 2010, through December 31, 2011, we studied 110,656 older adults residing in 607 nursing homes in Ontario, Canada.
  
  
  METHODS
  Nursing home-level antibiotic use was defined as use-days per 1000 resident-days, and facilities were classified as high, medium, and low use according to tertile of use. Multivariable logistic regression modeling was performed to assess the effect of nursing home-level antibiotic use on the individual risk of antibiotic-related adverse outcomes.
  
  
  METHODS
  Antibiotic-related harms included Clostridium difficile, diarrhea or gastroenteritis, antibiotic-resistant organisms (which can directly affect recipients and indirectly affect nonrecipients), allergic reactions, and general medication adverse events (which can affect only recipients).
  
  
  RESULTS
  Antibiotics were provided on 2,783,000 of 50,953,000 resident-days in nursing homes (55 antibiotic-days per 1000 resident-days). Antibiotic use was highly variable across homes, ranging from 20.4 to 192.9 antibiotic-days per 1000 resident-days. Antibiotic-related adverse events were more common (13.3%) in residents of high-use homes than among residents of medium-use (12.4%) or low-use homes (11.4%) (P < .001); this trend persisted even among the residents who did not receive antibiotic treatments. The primary analysis indicated that residence in a high-use nursing home was associated with an increased risk of a resident experiencing an antibiotic-related adverse event (adjusted odds ratio, 1.24; 95% CI, 1.07-1.42; P = .003). A sensitivity analysis examining nursing home-level antibiotic use as a continuous variable confirmed an increased risk of resident-level antibiotic-related harms (adjusted odds ratio, 1.004 per additional day of nursing home antibiotic use; 95% CI, 1.001-1.006; P = .01).
  
  
  CONCLUSIONS
  Antibiotic use is highly variable across nursing homes; residents of high-use homes are exposed to an increased risk of antibiotic-related harms even if they have not directly received these agents. Antibiotic stewardship is needed to improve the safety of all nursing home residents.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada2Division of Infectious Diseases, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada3Institute of Health Policy, Management and Eva.
authors.forename: Nick
authors.initials: N
authors.lastname: Daneman
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada3Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Bronskill
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada3Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada4Women's College Research Institute, Women's College Hospital, University of Toronto.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gruneir
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Alice M
authors.initials: AM
authors.lastname: Newman
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Hadas D
authors.initials: HD
authors.lastname: Fischer
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada3Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada4Women's College Research Institute, Women's College Hospital, University of Toronto.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Rochon
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada3Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Anderson
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada3Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada6Division of General Internal Medicine, Mount Sinai Hospital, University of Toronto.
authors.forename: Chaim M
authors.initials: CM
authors.lastname: Bell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D003967:Diarrhea / Q000139:chemically induced / Q000453:epidemiology; D004342:Drug Hypersensitivity / Q000453:epidemiology* / Q000209:etiology; D024881:Drug Resistance, Bacterial; D004761:Enterocolitis, Pseudomembranous / Q000139:chemically induced / Q000453:epidemiology*; D005260:Female; D005759:Gastroenteritis / Q000139:chemically induced / Q000453:epidemiology; D006707:Homes for the Aged; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D009735:Nursing Homes; D009864:Ontario / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*
chemical_list: D000900:Anti-Bacterial Agents