title: Patient safety: numerical skills and drug calculation abilities of nursing students and registered nurses.
abstract: OBJECTIVE
  This paper is a report of a correlational study of the relations of age, status, experience and drug calculation ability to numerical ability of nursing students and Registered Nurses.
  
  
  BACKGROUND
  Competent numerical and drug calculation skills are essential for nurses as mistakes can put patients' lives at risk.
  
  
  METHODS
  A cross-sectional study was carried out in 2006 in one United Kingdom university. Validated numerical and drug calculation tests were given to 229 second year nursing students and 44 Registered Nurses attending a non-medical prescribing programme.
  
  
  RESULTS
  The numeracy test was failed by 55% of students and 45% of Registered Nurses, while 92% of students and 89% of nurses failed the drug calculation test. Independent of status or experience, older participants (> or = 35 years) were statistically significantly more able to perform numerical calculations. There was no statistically significant difference between nursing students and Registered Nurses in their overall drug calculation ability, but nurses were statistically significantly more able than students to perform basic numerical calculations and calculations for solids, oral liquids and injections. Both nursing students and Registered Nurses were statistically significantly more able to perform calculations for solids, liquid oral and injections than calculations for drug percentages, drip and infusion rates.
  
  
  CONCLUSIONS
  To prevent deskilling, Registered Nurses should continue to practise and refresh all the different types of drug calculations as often as possible with regular (self)-testing of their ability. Time should be set aside in curricula for nursing students to learn how to perform basic numerical and drug calculations. This learning should be reinforced through regular practice and assessment.
authors.affiliation: Faculty of Health, University of Plymouth, UK. mmcmullan@plymouth.ac.uk
authors.forename: Miriam
authors.initials: M
authors.lastname: McMullan
authors.forename: Ray
authors.initials: R
authors.lastname: Jones
authors.forename: Susan
authors.initials: S
authors.lastname: Lea
mesh_terms: D000328:Adult; D002983:Clinical Competence; D003430:Cross-Sectional Studies; D054796:Drug Dosage Calculations; D004506:Education, Nursing / Q000379:methods; D004521:Educational Measurement / Q000379:methods; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D008508:Medication Errors / Q000517:prevention & control; D008875:Middle Aged; D009726:Nurses / Q000592:standards*; D015402:Nursing Education Research / Q000379:methods; D013338:Students, Nursing; D055815:Young Adult