title: eDrugCalc: an online self-assessment package to enhance medical students' drug dose calculation skills.
abstract: OBJECTIVE
  Dose calculation errors can cause serious life-threatening clinical incidents. We designed eDrugCalc as an online self-assessment tool to develop and evaluate calculation skills among medical students.
  
  
  METHODS
  We undertook a prospective uncontrolled study involving 1727 medical students in years 1-5 at the University of Edinburgh. Students had continuous access to eDrugCalc and were encouraged to practise. Voluntary self-assessment was undertaken by answering the 20 questions on six occasions over 30 months. Questions remained fixed but numerical variables changed so each visit required a fresh calculation. Feedback was provided following each answer.
  
  
  RESULTS
  Final-year students had a significantly higher mean score in test 6 compared with test 1 [16.6, 95% confidence interval (CI) 16.2, 17.0 vs. 12.6, 95% CI 11.9, 13.4; n= 173, P < 0.0001 Wilcoxon matched pairs test] and made a median of three vs. seven errors. Performance was highly variable in all tests with 2.7% of final-year students scoring < 10/20 in test 6. Graduating students in 2009 (30 months' exposure) achieved significantly better scores than those in 2007 (only 6 months): mean 16.5, 95% CI 16.0, 17.0, n= 184 vs. 15.1, 95% CI 14.5, 15.6, n= 187; P < 0.0001, Mann-Whitney test. Calculations based on percentage concentrations and infusion rates were poorly performed. Feedback showed that eDrugCalc increased confidence in calculating doses and was highly rated as a learning tool.
  
  
  CONCLUSIONS
  Medical student performance of dose calculations improved significantly after repeated exposure to an online formative dose-calculation package and encouragement to develop their numeracy. Further research is required to establish whether eDrugCalc reduces calculation errors made in clinical practice.
authors.affiliation: Departments of Neuroscience, Learning Technology Section and Clinical Pharmacology Unit, University of Edinburgh, College of Medicine and Veterinary Medicine, Edinburgh, UK. d.s.mcqueen@ed.ac.uk
authors.forename: Daniel S
authors.initials: DS
authors.lastname: McQueen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Begg
authors.forename: Simon R J
authors.initials: SR
authors.lastname: Maxwell
mesh_terms: D002983:Clinical Competence / Q000592:standards*; D054796:Drug Dosage Calculations; D004504:Education, Medical, Undergraduate / Q000379:methods*; D005246:Feedback; D006801:Humans; D020407:Internet; D009862:Online Systems; D013663:Teaching / Q000379:methods