title: Unit of measurement used and parent medication dosing errors.
abstract: OBJECTIVE
  Adopting the milliliter as the preferred unit of measurement has been suggested as a strategy to improve the clarity of medication instructions; teaspoon and tablespoon units may inadvertently endorse nonstandard kitchen spoon use. We examined the association between unit used and parent medication errors and whether nonstandard instruments mediate this relationship.
  
  
  METHODS
  Cross-sectional analysis of baseline data from a larger study of provider communication and medication errors. English- or Spanish-speaking parents (n = 287) whose children were prescribed liquid medications in 2 emergency departments were enrolled. Medication error defined as: error in knowledge of prescribed dose, error in observed dose measurement (compared to intended or prescribed dose); >20% deviation threshold for error. Multiple logistic regression performed adjusting for parent age, language, country, race/ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease; site.
  
  
  RESULTS
  Medication errors were common: 39.4% of parents made an error in measurement of the intended dose, 41.1% made an error in the prescribed dose. Furthermore, 16.7% used a nonstandard instrument. Compared with parents who used milliliter-only, parents who used teaspoon or tablespoon units had twice the odds of making an error with the intended (42.5% vs 27.6%, P = .02; adjusted odds ratio=2.3; 95% confidence interval, 1.2-4.4) and prescribed (45.1% vs 31.4%, P = .04; adjusted odds ratio=1.9; 95% confidence interval, 1.03-3.5) dose; associations greater for parents with low health literacy and non-English speakers. Nonstandard instrument use partially mediated teaspoon and tablespoon-associated measurement errors.
  
  
  CONCLUSIONS
  Findings support a milliliter-only standard to reduce medication errors.
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York; yinh02@med.nyu.edu.
authors.forename: H Shonna
authors.initials: HS
authors.lastname: Yin
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York;
authors.forename: Benard P
authors.initials: BP
authors.lastname: Dreyer
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York;
authors.forename: Donna C
authors.initials: DC
authors.lastname: Ugboaja
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York;
authors.forename: Dayana C
authors.initials: DC
authors.lastname: Sanchez
authors.affiliation: Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Paul
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York;
authors.forename: Hannah A
authors.initials: HA
authors.lastname: Moreira
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Woodhull Medical Center, New York, New York.
authors.forename: Luis
authors.initials: L
authors.lastname: Rodriguez
authors.affiliation: Department of Pediatrics, New York University School of Medicine and Bellevue Hospital Center, New York, New York;
authors.forename: Alan L
authors.initials: AL
authors.lastname: Mendelsohn
mesh_terms: D002675:Child, Preschool; D003430:Cross-Sectional Studies; D061827:Dimensional Measurement Accuracy; D054796:Drug Dosage Calculations; D005260:Female; D006801:Humans; D008297:Male; D008508:Medication Errors / Q000517:prevention & control*; D010290:Parents; D014894:Weights and Measures / Q000592:standards*
keywords: ambulatory care; health communication; health literacy; medication errors