Dose 4 You: Dose Division Calculator—A Tool to Reduce Calculation Errors

Abstract

Background: Medication dosing calculation errors can cause significant harm to patients, especially in the pediatric population. Crushing tablets for dose division purposes may increase the risk of calculation errors, which can lead to incorrect dosing and compromised patient safety. This study aimed to develop a calculator to eliminate calculation errors associated with dose division. Methods: Using the Wix platform, a group of pharmacists created a user-friendly webpage “Dose 4 You.” To enable accurate dose division calculations, the advanced language model Chat GPT and Visual Studio were used. The tool assists healthcare professionals through a step-by-step process, allowing them to enter the necessary dose and medication requirements. The Dose 4 You web page’s reliability and feasibility were assessed using retrospective data and validated questionnaires, including the System Usability Scale (SUS), respectively and a Likert scale-based acceptance questionnaire. Results: The Dose 4 You website calculated the required amount of powdered tablet to achieve the desired dose with 100% accuracy. The obtained SUS score was 88.38, indicating excellent usability. The average score of all questions for acceptance was found to be 4.7 ± 0.15 indicating a strong agreement on the tool’s usefulness and effectiveness. Conclusion: Dose 4 You is a reliable tool that improves patient safety by streamlining dose calculations and lowering calculation errors. The tool’s ease of use, practicality in daily clinical practice, and potential to reduce medication errors are highlighted by the positive perception among healthcare professionals. Dose 4 You’s successful implementation demonstrates the power of technology and collaboration in transforming medication administration and improving patient outcomes. Similar innovative solutions to optimize healthcare practices can be explored in future health informatics endeavors.

Introduction

Oral dosage forms of medications are available in various strengths, which meet the needs of most patients. However, factors such as the patient’s specific dosage requirements, or the commercial unavailability of the required dose in any other dosage form, leave the healthcare professionals to consider alternative strategies to meet the requirements such as crushing conventional tablets into smaller pieces or powders to achieve the desired dose. Crushing tablets for oral administration should be individually evaluated due to the potential for significant drug loss.

However, not all forms of tablets are suitable for splitting or crushing into powder forms. Sustained-release tablets, controlled-release tablets, extended-release tablets, disintegrating tablets, enteric-coated tablets, and film-coated tablets are modified oral dosage forms that should not be crushed. Furthermore, narrow therapeutic index drugs, liquid-filled capsules, irritants, and teratogens should not be crushed, in addition to these modified dosage forms. ¹

Crushing oral dosage forms may alter the pharmacokinetics and bioavailability of medicinal products, leading to under- or overdosage, which in turn may result in adverse effects. Such changes may be particularly important for medicinal products with narrow therapeutic windows, such as phenytoin, digoxin, carbamazepine, theophylline, or sodium valproate, where minor variations in dosage may lead to therapeutic failure or toxicity, as the narrow range between effective treatment and toxicity requires precise dosing, which may be compromised by crushing. ²

Although crushing conventional tablets may be useful in certain cases, one must be cautious about the calculation errors it entails. These errors may occur due to decimal placement errors, which may be misspelled or misread, resulting in dispensing or administering incorrect doses. For example, 1.0 mg can be misread as 10 mg or leading zeros can be omitted (eg, .5 mg instead of 0.5 mg, causing .5 mg to be misread as 5 mg). This may result in a 10-fold overdose, which is likely to result in increased toxicity, or a 10-fold underdose, thus resulting in overall decreased efficacy. ³

More than 7.5 million preventable medication errors occur in pediatric patients in the United States alone each year. ⁴ Medication errors affect approximately 5%-10% of all pediatric inpatients, and dosing errors are the most common type of medication error. ⁵

Mulac et al. explicitly emphasized dosing errors, which were (38%) of the most frequently reported medication errors in the Norwegian Incident Reporting System. ⁶ In incoherence, Doherty and McDonnell’s report on a 5-year experience at a college-affiliated children’s hospital was dismayed at a total of 6643 medication errors, of which 252 medication errors were related to medication dosing 10-fold errors. ³ Not just these studies, there has been evidence on dose calculation errors to be the most commonly reported errors, that compromise patient safety.^{7 -9}

Understanding the inevitabilities of the need for dose divisions and restriction for resources to conduct without errors, the researchers have developed a free-to-use webpage “Dose 4 You” dose division calculator webpage.

This webpage is designed to help healthcare professionals accurately calculate the amount of powder (crushed tablet) to be dispensed based on the patient’s requirements, as prescribed by their treating physician. Using this tool may eliminate the risk of calculation errors and, thus, promote patient safety.

Methods

A team of pharmacists was involved in the development of Dose 4 You. The webpage (Figure 1) was built using the user-friendly and versatile Wix platform ¹⁰ which is known for its intuitive user interface and extensive customization options for creating websites and applications. This allowed the team to quickly create a functional and visually appealing webpage that allowed for seamless user interaction.

Figure 1.

Dose 4 You web page screenshot.

To enhance the functionality of the webpage and enable accurate dose calculations, Chat GPT, a state-of-the-art language model from OpenAI, ¹¹ and Visual Studio, a creative launching pad from Microsoft, ¹² were used to write the underlying Hypertext Markup Language (HTML) code for dose division calculations. The HTML code was deployed in the developed webpage interface to create a fully functional webpage for easy input and instant generation of accurate dose calculations.

The user-friendly interface of the webpage guides users through the process step-by-step, allowing them to enter relevant information, such as the labeled dose, required dose, and other specific medication requirements.

The Step-by-Step Procedure

The amount to be dispensed for tablets are as follows:

Required dose of drug = x

Weight of “n” number of tablets = a (in grams)

Weight of powdered tablets = b (in grams)

Labelled amount of drug in formulation* Number of tablets taken = c

Amount of drug present in the powdered tablet = b* c/a = d (in grams)

Amount of powder to be weighed = x* b/d = y (in grams)

Reliability and Feasibility Testing

The Dose 4 You was evaluated for its reliability and feasibility. Retrospective data was used to test the reliability of the Dose 4 You webpage. A validated questionnaire, the System Usability Scale (SUS) ¹³ and a developed Likert scale-based (strongly disagree:1 to strongly agree:5) questionnaire for acceptance were used to assess usability and acceptance, respectively. To calculate the SUS score, the score of each item isranged from 0 to 4. For items 1, 3, 5, 7, and 9, the score is obtained by scale position minus 1. For items 2, 4, 6, 8, and 10, the score is obtained by 5 minus the scale position. The overall SUS score is obtained by multiplying the sum of the scores by 2.5. SUS Scores between 51 and 68 are classified as “poor” or “D.” Scores below 51 are classified as “awful” or as “F.” Alternatively, scores between 68 and 80.3 are given a grade of “Good” or “B,” while scores above 80.3 are given an “Excellent” or “A.”

The research group conducted an extensive literature search and adopted the ad-hoc Likert-based questionnaire from Pinar Manzanet et al. ¹⁴ and developed a modified version of the Likert scale-based questionnaire for acceptance.

Participants and Survey Procedure

For reliability and feasibility testing, Pharm D interns and clinical pharmacy residents were invited to participate in this study as a target population because they are involved in dose division activities. The research pharmacist sent the invite via email to complete the Google Form questionnaire, which captured their demographic details and responses to both questionnaires.

Results

The Dose 4 You webpage provides healthcare professionals with a reliable tool that ensures rapid and accurate calculations tailored to the specific needs of each patient, thus enabling safer and more effective drug administration. Careful research and extensive testing conducted by the development team ensured the accuracy and effectiveness of the calculator, guaranteeing reliable results for patients.

This web-based calculator serves a dual function: first, it aids in determining the precise weight of powdered medication, and second, it evaluates the precision of manual dose calculations. Importantly, it maintains a strict privacy policy by not retaining any user or personal information, ensuring that no traceable reports are generated.

A total of 200 patient dose division retrospective data were used to test the calculator. The results obtained in calculating the required amount of powdered tablets needed to achieve the desired dose were 100% accurate.

The usability and acceptance assessment of the Dose 4 You calculator involved the participation of 20 Pharm D interns and Clinical Pharmacy residents practicing in a tertiary care teaching hospital who completed the questionnaires. The mean age of the participants was 24.1 ± 0.91 (standard deviation) years, and the majority were female [16 (80%)]. The majority of the participants were Pharm D interns [18 (90%)] and 10% were clinical pharmacy residents.

The overall SUS score for the Dose 4 You calculator obtained was 88.38, which is above 80.3, therefore the tool’s usability is “Excellent” or Grade “A.” The mean scores of the SUS questionnaire for the Dose 4 You calculator are shown in Table 1. This indicates that the user interface, step-by-step guidance, and calculation functionality of the webpage were well received by the participants, demonstrating its effectiveness in providing a seamless user experience.

Table 1.

SUS Questionnaire Score.

No.	SUS questions	Mean ± SD*
1.	I think that I would like to use this system frequently.	3.80 ± 0.41
2.	I found the system unnecessarily complex.	3.55 ± 0.94
3.	I thought the system was easy to use.	3.65 ± 0.75
4.	I would need the support of a technical person to be able to use this system.	3.70 ± 0.73
5.	I found the various functions in this system were well integrated.	3.45 ± 0.94
6.	I thought there was too much inconsistency in this system.	3.65 ± 0.75
7.	I would imagine that most people would learn to use this system very quickly.	3.75 ± 0.44
8.	I found the system very cumbersome to use.	3.20 ± 1.36
9.	I felt very confident using the system.	3.55 ± 0.69
10.	I needed to learn a lot of things before I could get going with this system.	3.05 ± 1.23

^*Standard deviation.

The developed Likert scale-based questionnaire provided insights into participants’ acceptance of the Dose 4 You calculator. The average score of all questions for acceptance was found to be 4.7 ± 0.15 indicating a strong agreement on the tool’s usefulness and effectiveness. The mean scores of the developed Likert-scale questionnaire for acceptance are shown in Table 2. Most participants reported “strongly agree” with questions about acceptance, which validates the calculator’s positive reception among healthcare professionals.

Table 2.

Likert Scale Questionnaire for Acceptance Score.

No.	Acceptance question	Mean ± SD*
1.	The results of the calculation obtained with the Dose 4 You calculator are easy to interpret.	4.65 ± 0.75
2.	The results of the calculation obtained with the Dose 4 You calculator are useful for my daily work.	4.55 ± 0.76
3.	The Dose 4 You calculator allows me to do the dose calculations confidently.	4.7 ± 0.57
4.	Dose 4 You calculator reduces the dose-related calculation errors.	4.75 ± 0.44
	Mean score	4.7 ± 0.15

^*Standard deviation.

Conclusion

By leveraging user-friendly web development platforms and state-of-the-art language models, healthcare professionals can now access tools that streamline calculations and enhance patient safety. All participants reported a positive perception of the Dose 4 You calculator in terms of ease of use, usefulness in daily clinical practice, and reduced calculation errors.

Dose 4 You is a testament to the potential of collaboration between technology and healthcare expertise. The integration of web-based tools and advanced language models can revolutionize medication administration, promote safer practices, and ultimately improve patient outcomes. The success of Dose 4 You paves the way for further exploration and implementation of innovative solutions in the field of health informatics.

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