Calculating drug doses

About 70-80% of undergraduates entering medical training in Britain have passed mathematics at A level, and virtually all will have passed the subject at O level. Yet, as Rolfe and Harper show, among a representative sample of 150 doctors asked to perform simple calculations converting drug doses from a percentage or dilution to mass per volume the success rate was as low as 16% (p 1173).1 The results showed that senior doctors (consultants and senior registrars) were better at calculating the correct answer, and anaesthetists were notably better. While these data seem to suggest a hierarchy in numerical skill among doctors, in terms of both age and specialty, clearly there are …