A survey of drug-dose calculation skills of Australian tertiary hospital doctors

Perception of pharmacy students toward numeracy: An observational study from King Saud University, Riyadh Saudi Arabia

Background and objective

Numeracy is the branch of mathematics involved in understanding basic calculations, quantitation, estimation, reasoning, and execution of multistep operations. It is very imperative that pharmacists understand and apply numeracy skills in their routine work in the interest of their profession and patient care. This observational study was designed to assess the pharmacy student's perceptions of numeracy.

Methods

A prospective observational study was conducted by the Department of Pharmacy, King Saud University, Kingdom of Saudi Arabia, between December 2021 and February 2022. All the enrolled subjects pursued a 5-year Pharma degree course at the university using a 9-item instrument, which accessed the perception of students toward numeracy. The data were analyzed using the statistical software statistical package for social science (SPSS) version 26.0 (SPSS Inc., Chicago, IL, USA). Chi-square and Fisher's exact test were used to derive an association between various parameters of the study subjects. A P-value of < 0.05 was taken as statistically significant.

Results

A total of 550 pharmacy students were approached in this study, out of which 21 (3.8%) students were excluded due to incompleteness of the responses; thereupon, 529 students were included in the study. We learned that almost 90.0% of students had excellent and/or good mathematical ability, but at the same time, they were frequent users of calculators. Most of the students endorsed the importance of numeracy and showed their interest in attaining more knowledge of numeracy. Similarly rating the perceptions of mathematical ability is significantly associated with the frequency of use of a calculator for calculations (p = 0.0001).

Conclusion

Pharmacy students showed interest in numeracy and correspondingly showed excellent perceptions toward mathematical ability. Although the role of numeracy has been well accepted, inciting changes in teaching-learning practices through mathematically focused teaching approaches throughout the pharmacy program will increase its applicability in healthcare.

[Prescription of phosphorus, calcium and magnesium: choice of the millimole unit to establish the equivalence of doses between oral and injectable forms]

OBJECTIVES

Information available on the packaging of drugs indicated for patients electrolytes replenishment differs from one manufacturer to another. They relate, for example, the unit chosen to express elemental electrolyte concentration. These differences constitute a risk factor for medication errors. This article proposes a clinical decision support tool which defines dose equivalences between the oral and injectable formulation galenic forms for medications providing phosphorus, calcium and magnesium and a calculated replenishment ratio.

METHODS

The amounts of elemental electrolyte were determined from the information contained on the packaging and the summaries of product characteristics. Only the specialties of our hospital drug formulary were studied. For each element, the replenishment ratio was determined from published data.

RESULTS

Equivalence tables were created for the phosphorus, calcium and magnesium between oral and injectable formulation. A clinical decision support tool was developed from these data.

CONCLUSION

The use of this tool is a first way to reduce the risk of medication errors. It remains to determine the conditions for its dissemination and evaluation. This issue raises the questions of the exclusive use of the millimole unit on packaging and for prescription, and that of the integration of this type of tool into prescription software and decision support systems.

Drug Calculation Errors in Anesthesiology Residents and Faculty: An Analysis of Contributing Factors

BACKGROUND

Limited data exist regarding computational drug error rates in anesthesia residents and faculty. We investigated the frequency and magnitude of computational errors in a sample of anesthesia residents and faculty.

METHODS

With institutional review board approval from 7 academic institutions in the United States, a 15-question computational test was distributed during rounds. Error rates and the magnitude of the errors were analyzed according to resident versus faculty, years of practice (or residency training), duration of sleep, type of question, and institution.

RESULTS

A total of 371 completed the test: 209 residents and 162 faculty. Both groups committed 2 errors (median value) per test, for a mean error rate of 17.0%. Twenty percent of residents and 25% of faculty scored 100% correct answers. The error rate for postgraduate year 2 residents was less than for postgraduate year 1 (P = .012). The error rate for faculty increased with years of experience, with a weak correlation (R = 0.22; P = .007). The error rates were independent of the number of hours of sleep. The error rate for percentage-type questions was greater than for rate, dose, and ratio questions (P = .001). The error rates varied with the number of operations needed to calculate the answer (P < .001). The frequency of large errors (100-fold greater or less than the correct answer) by residents was twice that of faculty. Error rates varied among institutions ranged from 12% to 22% (P = .021).

CONCLUSIONS

Anesthesiology residents and faculty erred frequently on a computational test, with junior residents and faculty with more experience committing errors more frequently. Residents committed more serious errors twice as frequently as faculty.

The need to address poor numeracy skills in the emergency department environment

Substantial evidence exists for lack of numerical skills among many health professionals. Although poor numeracy has long been recognised as a contributor to medication error, other activities for which numerical literacy are required, such as interpretation of diagnostic results, have been largely ignored. Poor self-awareness of lack of numerical literacy increases the risk, especially in the busy and hurried emergency environment. System changes, such as standardising units and improving number presentation, reduce the potential for misinterpretation; however system changes do not address the underlying deficiencies in mathematical skills. The training of doctors in numeracy has been largely ignored. In contrast, education for nurses frequently occurs during both pre- and post-registration programmes. Interventions have had mixed success, although additional emphasis in increasing conceptual understanding of numbers is encouraging. The consequences of poor numerical literacy should be addressed in all clinical staff, not only by practice change to remove the potential for errors to be made, but also complemented by self-awareness and education.

eDrugCalc: an online self-assessment package to enhance medical students' drug dose calculation skills

AIMS

Dose calculation errors can cause serious life-threatening clinical incidents. We designed eDrugCalc as an online self-assessment tool to develop and evaluate calculation skills among medical students.

METHODS

We undertook a prospective uncontrolled study involving 1727 medical students in years 1-5 at the University of Edinburgh. Students had continuous access to eDrugCalc and were encouraged to practise. Voluntary self-assessment was undertaken by answering the 20 questions on six occasions over 30 months. Questions remained fixed but numerical variables changed so each visit required a fresh calculation. Feedback was provided following each answer.

RESULTS

Final-year students had a significantly higher mean score in test 6 compared with test 1 [16.6, 95% confidence interval (CI) 16.2, 17.0 vs. 12.6, 95% CI 11.9, 13.4; n= 173, P < 0.0001 Wilcoxon matched pairs test] and made a median of three vs. seven errors. Performance was highly variable in all tests with 2.7% of final-year students scoring < 10/20 in test 6. Graduating students in 2009 (30 months' exposure) achieved significantly better scores than those in 2007 (only 6 months): mean 16.5, 95% CI 16.0, 17.0, n= 184 vs. 15.1, 95% CI 14.5, 15.6, n= 187; P < 0.0001, Mann-Whitney test. Calculations based on percentage concentrations and infusion rates were poorly performed. Feedback showed that eDrugCalc increased confidence in calculating doses and was highly rated as a learning tool.

CONCLUSIONS

Medical student performance of dose calculations improved significantly after repeated exposure to an online formative dose-calculation package and encouragement to develop their numeracy. Further research is required to establish whether eDrugCalc reduces calculation errors made in clinical practice.