Background and Importance Humans make mistakes, inadvertently when making poor decisions, being distracted or when not perceiving risk whilst managing medications. Health professionals do not make mistakes on purpose, yet medication errors remain the most common type of medical errors. A human factors approach can be applied to address the causation of medication errors from a process point of view while addressing our error-prone human nature. Intravenous medications are complex to prepare and administer. Specific tasks, such as diluting intravenous medications are at a higher risk of medication errors.

Aim and Objectives This study aims to address human factors in medication calculation errors involving dilution of intravenous medications.

Material and Methods From the medication errors reported in 2016 and 2017 to the Norwegian Incident Reporting System, we specifically scrutinised medication calculation errors that required dilution during medication preparation, dispensing and administration. We included real events that had reached the patients, and which contained sufficient incident description to allow for causal analysis. From the incident descriptions, we conducted a content analysis of human factors.

Results In total, 14 incidents met the inclusion criteria and involved the dilution of morphine, oxycodone, adrenalin, and noradrenalin. Several human factors exposed the intravenous preparation process to risks. For example, performing tasks with cognitive loads, such as dilution, followed by bedside dose calculation whilst providing patient care. Some dilution errors were caused by not knowing the exact concentration after dilution, which resulted in one infant receiving 7 mg of morphine instead of 0.7 mg. Administering from a syringe that contains more than the prescribed dose was found as a high-risk practice. Most dilution errors led to overdosages and resulted in patient harm.

Conclusion and Relevance This study discusses how cognitive processing is related to medication errors. Addressing human factors that contributed to medication errors should involve systemic measures which take in account how humans think and process information to avoid patient harm from dilution errors.

Conflict of Interest No conflict of interest