title: Variability in pharmacy interpretations of physician prescriptions.
abstract: BACKGROUND
  The clarity of prescription drug instructions is a health literacy and medication safety concern.
  
  
  OBJECTIVE
  To assess the variability of pharmacy interpretations of physician prescriptions.
  
  
  METHODS
  Identically written prescriptions for 4 common medications (atorvastatin, alendronate, trimethoprim/sulfamethoxazole, ibuprofen) were filled in 6 pharmacies (2 largest chains, 2 grocery stores, 2 independents) in 4 cities (Boston, Chicago, Los Angeles, Austin).
  
  
  METHODS
  Components of the instruction were coded as dose, frequency, administration route, timing, indication, and auxiliary instructions.
  
  
  RESULTS
  In all, 85 labels were evaluated. Dose frequency was omitted on 6% of instructions ("take 1 tablet for cholesterol"). Timing was explicitly stated on 2% of instructions ("in the morning"). All prescriptions included indications; pharmacies transcribed these onto 38% of labels. The prescription for alendronate stated not to lie down for at least 30 minutes after taking; this was transcribed with 50% of instructions. Reading difficulty was above recommended levels for 46% of instructions; with 14% greater than a high school level.
  
  
  CONCLUSIONS
  Efforts are needed to ensure patients receive clear, consistent information supporting safe medication use.
authors.affiliation: , Center for Communication in Healthcare, Institute for Healthcare Studies and Division of General Internal Medicine, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, USA. mswolf@northwestern.edu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Wolf
authors.forename: Paul
authors.initials: P
authors.lastname: Shekelle
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
authors.forename: Jessica
authors.initials: J
authors.lastname: Agnew-Blais
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Parker
authors.forename: William H
authors.initials: WH
authors.lastname: Shrank
mesh_terms: D019386:Alendronate / Q000008:administration & dosage; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D000069059:Atorvastatin; D050071:Bone Density Conservation Agents / Q000008:administration & dosage; D032882:Comprehension; D000075202:Contraindications; D004346:Drug Information Services / Q000592:standards; D004348:Drug Labeling / Q000592:standards*; D011307:Drug Prescriptions / Q000592:standards*; D064420:Drug-Related Side Effects and Adverse Reactions; D004512:Education, Pharmacy; D004522:Educational Status; D005260:Female; D006538:Heptanoic Acids / Q000008:administration & dosage; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage; D007052:Ibuprofen / Q000008:administration & dosage; D010353:Patient Education as Topic; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D010594:Pharmacies / Q000592:standards*; D011361:Professional Competence; D011758:Pyrroles / Q000008:administration & dosage; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage; D019037:Urban Health Services / Q000592:standards; D014956:Writing
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D050071:Bone Density Conservation Agents; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D004364:Pharmaceutical Preparations; D011758:Pyrroles; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D000069059:Atorvastatin; D007052:Ibuprofen; D019386:Alendronate