Modern medication treatment is complex and dynamic. Sophisticated treatments are created to cater for patients with multiple comorbidities of whom would benefit from personalised dosing regimens. As we gain further insights into drug pharmacokinetics and toxicology, doctors are now required to prescribe medicine according to each patient’s physiological characteristics whenever possible.

The effect of a medication largely depends on its concentration at the target receptor sites. Too high a dose could lead to toxicity and side effects; too little will render the treatment ineffective. Antibiotics therapy in paediatric patients exemplifies this concept succinctly: all dosage must be adjusted according to the child’s weight so the blood concentration can reach the ideal “Goldilock” level.

Prescribing and dosing errors
According to the Agency for Healthcare Research and Quality (AHRQ), medication errors are still prevalent despite much efforts have been invested to prevent them. Intravenous anticoagulant heparin, for example, has the highest risk of causing harm when used inappropriately (1). Heparin must be prescribed based on weight in order to avoid any potential harm such as bleeding complications or clotting risks.

It was recently shown that anticoagulant medication errors occurred mostly in the hospital setting, of which over half (56.2%) were attributed to low molecular weight heparin and over one-quarter (27.7%) were due to vitamin K antagonist. More importantly, human factors were the most significant cause of errors (53.4%), including performance deficit and not following protocol and guidelines in prescribing (2).

Another crucial area in which precise dosage calculation is necessary is in the care of children. Unlike adult patients, paediatric patients have a much broader range of age and size which entail dosage individualisation. This is most commonly performed using dosage equations but some studies indicated that clinicians may have inadequate calculation skills (3). A slight error may cause harms to manifest in a disproportionate manner: think about a wrongly placed decimal points that leads to a dosage to change 10-times stronger or weaker, or using “miligram” instead of “micrograms” would result in a thousand-fold difference in strength.

Indeed, incorrect dosage calculation is a common error. It was reported that “wrong dose” was the most common error in medical wards and intensive care units, with 35% of drug-related errors attributed to incorrect doses. Furthermore, a study that examined nurses’ skills in drug dose calculation found that 24% of them made arithmetic mistakes (4).

It is clear that dosage mis-calculation is prevalent among healthcare professionals and the issue must receive appropriate attention lest more harm to patients would be incurred.

Preventing an error before it happens
To mitigate the potential harms to patient, timely recognition of medication or dosing errors must be prioritised. EHR systems with advanced medication module offers the ideal platform to monitor the medication process and prevent any dosing or prescribing errors. A variety of algorithms have been developed for these purposes, but most rely on static formula that does not respond well to the dynamic changes in patient condition or the need for frequent dose adjustment (5).

Furthermore, an excellent system must be pragmatic and suited to clinician workflow in order to minimise fatigue from false alarm. Our COSMIC medication module, for example, has undergone three major transformations through numerous real-world practice experience. This tried-and-tested solutions could incorporate patient context when screening for drugs or dosage needs, thus significantly improving the safety and precision of any clinical therapies. In fact, smart EHR systems that include the right patient context has been shown to be superior in detecting medication errors without exacerbating alert fatigue among clinicians.

In short, the modern medical community has little appetite, nor it has the wiggle room to accommodate, for preventable medication errors. EHR systems must demonstrate good capacity in recognising and preventing medication errors, in particular, guarding against dose mis-calculation to ensure our most vulnerable patients are better protected.


1. Medication Errors and Adverse Drug Events | PSNet [Internet]. [cited 2019 Nov 15]. Available from:

2. Dreijer AR, Diepstraten J, Bukkems VE, Mol PGM, Leebeek FWG, Kruip MJHA, et al. Anticoagulant medication errors in hospitals and primary care: a cross-sectional study. Int J Qual Health Care J Int Soc Qual Health Care. 2019 Jun 1;31(5):346–52.

3. Lesar TS. Errors in the use of medication dosage equations. Arch Pediatr Adolesc Med. 1998 Apr;152(4):340–4.

4. Basak T, Aslan O, Unver V, Yildiz D. Effectiveness of the training material in drug-dose calculation skills. Jpn J Nurs Sci. 2016 Jul 1;13(3):324–30.

5. Ni Y, Lingren T, Hall ES, Leonard M, Melton K, Kirkendall ES. Designing and evaluating an automated system for real-time medication administration error detection in a neonatal intensive care unit. J Am Med Inform Assoc JAMIA. 2018 01;25(5):555–63.