Objective: To discover how well new house officers in primary care residency programs perform the mathematical calculations necessary to function effectively in pediatric and nursery settings. Design: Criterion-referenced survey examination testing unit conversion, fluid and rehydration management, and drug-dosing skills. Setting: Five primary care residencies in family practice and pediatrics at urban and community campus sites in Illinois. Participants: Twenty-three family practice residents and 11 pediatric residents tested during residency orientation sessions or in conferences during the first 3 months of training. Interventions: None. Results: The mean score for all residents was 42%. Pediatric residents (mean score, 57.8%) performed significantly better than family medicine residents (mean score, 34.4%) (P=.002). Conversion from conventional to metric units was more difficult for family practice residents. but pediatric residents also made errors. Pediatric residents were significantly better than family medicine residents al calculation of fluid maintenance requirements (P<.05). Only 5 of 34 residents wrote acceptable fluid orders. Nutritional and drug therapy calculations showed fewer mathematical errors, but neither group routinely wrote medical orders that specified the drug or formula, concentration, volume required per dose or feeding, route of administration, dosing interval, and duration of therapy. Conclusions: The potential for serious clinical errors caused by faulty calculation of dosage by house staff officers is high. New residents should have their orders for fluids and drugs double-checked bg senior personnel early in their training. Residency programs should provide remedial skills training for house officers with deficiencies in applied mathematics. The medical school faculty needs to assess students' competence in mathematics before allowing independent clinical responsibility.
