title: Benzodiazepine-opioid co-prescribing in a national probability sample of ED encounters.
abstract: BACKGROUND
  Benzodiazepine-opioid combination therapy is potentially harmful due to the risk of synergistic respiratory depression, and the rate of death due to benzodiazepine-opioid overdose is increasing. Little is known about the prevalence and characteristics of benzodiazepine-opioid co-prescribing from the ED setting.
  
  
  METHODS
  Secondary analysis of data from the National Hospital Ambulatory Medical Care Survey, using sample weights to generate population estimates. The primary objective was to describe the annual prevalence of benzodiazepine-opioid co-prescribing from 2006 to 2012, using 95% confidence intervals (95% CI) to compare adjacent years. The secondary objective was to compare characteristics of ED encounters receiving a benzodiazepine-opioid co-prescription versus those receiving an opioid prescription alone, using a multivariable logistic regression.
  
  
  RESULTS
  The prevalence of benzodiazepine-opioid co-prescribing did not significantly change from 2006 to 2012. During this period, 2.7% (95% CI: 2.5-2.8%) of ED encounters prescribed an opioid were also prescribed a benzodiazepine. Relative to encounters receiving an opioid prescription alone, encounters receiving a co-prescription were more likely to represent a follow-up rather than initial visit (Odds Ratio [OR] 1.52), receive more medications (OR 1.41) and fewer procedures (OR 0.48) while in the ED, and more likely to have a diagnosis related to mental disorder (OR 20.60) or musculoskeletal problem (OR 3.71).
  
  
  CONCLUSIONS
  From 2006 to 2012, almost 3% of all ED encounters receiving an opioid prescription also received a benzodiazepine co-prescription. The odds of benzodiazepine-opioid co-prescribing were significantly higher in ED encounters representing a follow-up visit and in diagnoses relating to a mental disorder or musculoskeletal problem.
authors.affiliation: Department of Emergency Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; Center for Education in Health Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States. Electronic address: howard.kim@northwestern.edu.
authors.forename: Howard S
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Emergency Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; Center for Education in Health Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: McCarthy
authors.affiliation: Department of Emergency Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
authors.forename: D
authors.initials: D
authors.lastname: Mark Courtney
authors.affiliation: Department of Emergency Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Lank
authors.affiliation: Department of Communication Studies, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Lambert
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000009:adverse effects* / Q000627:therapeutic use; D001569:Benzodiazepines / Q000009:adverse effects* / Q000627:therapeutic use; D004347:Drug Interactions; D062787:Drug Overdose / Q000453:epidemiology / Q000401:mortality*; D004359:Drug Therapy, Combination / Q000009:adverse effects; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012131:Respiratory Insufficiency / Q000139:chemically induced*; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D001569:Benzodiazepines
keywords: Benzodiazepine; Opioid; Pain; Prescribing