Factors influencing doctors' ability to calculate drug doses correctly

Int J Clin Pract. 2007 Feb;61(2):189-94. doi: 10.1111/j.1742-1241.2006.01273.x.


Doctors and medical students are more likely to make errors in drug dose calculations when the strengths of drug solutions are expressed as ratios or percentages. We have already described how a doctor's specialty influences their drug dose calculation skills, having surveyed almost 3000 doctors in an online survey. Better teaching of drug administration skills or reinforcement of existing skills would appear to be needed. We sought to identify doctors that might benefit particularly from such teaching by other means than specialty alone, by subjecting existing data to further analysis. Almost 3000 doctors subscribing to a UK-based internet content provider had participated in an online questionnaire concerning drug-dose calculation. Each doctor's score in the multiple choice questionnaire was cross referenced with demographic data obtained from the hosts of the original survey whilst maintaining anonymity. Newly and recently qualified doctors, and doctors working in the community, struggled most with the calculations (p < 0.0001). There were also highly significant differences in the performances of doctors from different medical schools (p < 0.0001). As a new training programme for junior doctors is being introduced in the UK; we recommend that drug administration skills are given a prominent place in the curriculum, and again call for the standardisation of ampoule labelling to mass concentration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Clinical Competence / standards*
  • Drug Administration Schedule
  • Education, Medical, Undergraduate*
  • Educational Measurement
  • Humans
  • Medical Staff, Hospital / standards*
  • Medication Errors / prevention & control*
  • Pharmaceutical Preparations / administration & dosage*
  • Surveys and Questionnaires


  • Pharmaceutical Preparations