PCRF Research Alert: Paramedic Drug Calculations

Each month the Prehospital Care Research Forum combs the literature to identify recent studies relevant to EMS education practices. In this segment PCRF board member Megan Corry examines some alarming data about paramedic drug calculations.

Boyle MJ, Eastwood K. Drug calculation ability of qualified paramedics: A pilot study. World J Emerg Med, 2018; 9(1): 41–5. 

Paramedic practice includes the ability to make critical medical calculations under stressful circumstances and on calls that are infrequently encountered, such as pediatric emergencies. Multiple providers on scene and distractions in the environment, combined with a lack of a consistent communication approach to ensuring safety in medication administration, can increase the likelihood of error. 

Availability of aids such as calculators, charts, and length-based tapes does not always translate into their effective use. Research from the U.S. and international sources suggests that paramedic and nursing students and experienced providers are often unable to calculate appropriate dosages when given a test of common medications used in the emergency setting. 

The objective of this cross-sectional study by Australians Malcolm Boyle and Kathryn Eastwood was to identify the ability of qualified operational paramedics in Australia to calculate common drug dosages. A group of 20 practicing paramedics in their first year of an Australian University graduate program were given a previously validated 12-item written test containing five mathematical items and seven drug calculations. Participants were not allowed to use a calculator during the test. The participants included 16 males with an average age of 32 (25–46) employed as paramedics for over 7 years (4–12 years). 

Researchers used descriptive statistics and proportions to analyze basic demographic data and results of the test. Inferential statistics were used to determine differences among genders and compare other potentially confounding variables such as years of experience. Surveys taken prior to the test showed that while 74% of respondents reported frequently conducting calculations as part of their job and feeling skilled at it, 55% also felt they’d had poor initial education on drug calculations. Of the 20 participants, only 20% got all answers correct. Forty-two percent got scores of 50% or less. The overall average score was 72%, with no significant difference among experience levels. 

Analyzing the three categories of error, 60% made arithmetic errors (unable to operate the equation they had identified), 40% made conceptual errors (unable to identify relevant information to construct the proper equation), and 25% made computational errors (miscalculations in addition, subtraction, multiplication, or division). The authors concluded that this small study is consistent with other findings and demonstrates that not only paramedic students but practicing paramedics need ongoing practice with medical calculations. Of greater concern is the percentage of errors that would not be corrected by the addition of an aid such as a calculator, chart, or length-based tape (conceptual errors). The high percentage of arithmetic errors among experienced participants also suggests that drug-calculation drills should be included in continuing education as well as initial education. 

Although this study is limited by several factors, such as being a small sample from a single system, its subjects are a group of highly motivated and experienced paramedics attending the first year of a graduate EMS program—a group more likely to perform well on a test of common drug calculations. Yet more than half felt their initial paramedic education was substandard in preparing them for medical calculations in the field. Future research should combine action research and randomized studies to better address teaching and learning strategies that focus on addressing each specific type of calculation error, their effects on clinical practice changes, and ultimately on patient outcomes. 

Megan Corry, EdD, EMT-P, is the program director and full-time faculty for the City College of San Francisco paramedic program and on the board of advisors of the UCLA Prehospital Care Research Forum.