Introduction

An adverse event (AE) is defined as an undesired and unplanned occurrence, directly associated with the care or service provided to a patient in the healthcare system. An adverse drug event (ADE) is an injury from a medication or lack of an intended medication, and includes adverse drug reactions (ADRs) and harm from medication incidents.1 In the first national study of AEs in Canadian hospitals, it was found that 7.5% of hospital admissions were accompanied by at least one AE, and that over one-third of these events were deemed preventable.2 Approximately one-quarter of the AEs were related to medication or fluid administration. In a patient safety study conducted at the Winchester District Memorial Hospital (WDMH) in 2004, the majority of reported AEs were caused by medication use (50%), of which half were preventable.3 In a subsequent study examining aAEs suffered by patients after discharge from the hospital, it was found that 72% of events were drug related.4 Preventable AEs were classified most frequently as therapeutic errors, which consisted of the concomitant use of medications known to interact, the use of a treatment known to be contraindicated in a specific condition or the failure to adequately monitor a treatment.4 The Institute of Medicine has reported that as many as 44 000–98 000 deaths occur annually in hospitals in the USA from some type of medication error.5 All stages of the drug delivery process are susceptible to error, including prescribing, transcribing, dispensing and administration.6

Inaccuracies made during the drug prescribing stage, however, are the most common type of avoidable medication error.7 Prescribing decision errors have thus become an important target for improvement in the patient safety movement.

There is a wide range of factors contributing to medication errors, including distracted staff, lapses in memory, slips in attention, errors of judgement, lack of knowledge, communication problems, inadequate pharmacological training and a culture that does not support safe prescribing.8–10 If a prescriber lacks knowledge of the drug or patient in question, or if handwritten orders are illegible, incomplete or ambiguous, the likelihood of an ADE increases.11 In order to curtail the incidence of medication-related AEs, hospitals across the nation are implementing various safeguards in the medication use system.

For instance, computerised physician order entry, computerised decision support systems, pharmacist participation in medical rounds, bar coding systems, preprinted order forms and provision of key reference materials to staff are but a few examples.6 However, strategies that consist of purchasing new hardware or software can become prohibitively expensive, whereas other cost-efficient methods can still have a significant effect on medication safety. Creating a culture within the hospital of patient safety, developing standardised protocols (especially in relation to high-risk medications) and developing an educational programme are examples of such strategies.12

Medication safety teaching represents a recognised strategy in risk reduction, and is perhaps most valuable in the foundational years of medical education. More prescribing errors occur in the first year after graduation than in all other years.13 As mentioned above, many factors contribute to the susceptibility of committing a medication error. For junior doctors in particular, the most likely factor is a deficiency in clinical pharmacology training, causing a decreased confidence in safe prescribing skills.9 11 The American College of Chest Physicians recently released evidence-based guidelines on the effectiveness of continuing medical education (CME) on physician knowledge.14 Based on the association between knowledge-based certification and improved clinical performance, it was recommended that multimedia CME interventions (eg, video, audio, print) with multiple instructional techniques (eg, discussion groups, case-based learning) be used to improve physician knowledge.14

There are relatively few published studies on the effectiveness of medication safety educational interventions in medical students. With a focus on medication reconciliation, Lindquist et al evaluated the effect of an interactive simulation on the improvement in student knowledge and comfort in obtaining medication histories.15 Students received a 30-minute lecture on the necessities of obtaining an accurate medication history and tools available for acquiring more information from pertinent sources, then participated in a simulation which included a physician, pharmacist and actor playing the role of the patient. Students rated their knowledge level as having increased by 27% and their comfort level as having increased by 20%. Garbutt et al conducted two 1-hour, small-group, interactive educational sessions for third-year medical students, held 2 weeks apart.11 Following the intervention, the average number of error-free prescriptions (evaluated through verbal transcription of 10 prescription orders) increased fivefold from 0.82 per student to 4.54 per student. Following the intervention, the average number of errors and dangerous errors per student decreased from 14 to 7.4 (p<0.0001) and from 4.8 to 2.7 (p<0.0001), respectively. Pharmacy team conducted a pharmacist-facilitated teaching session given to 40 final-year medical students.16 The teaching consisted of five stations: managing anticoagulation, preparing intravenous medication, taking a medication history and writing an inpatient prescription, writing a discharge prescription that includes a controlled drug, and teaching inhaler technique. One month later, a random sample of 16 taught and 16 non-taught students participated in an objective structured clinical examination (OSCE), which resulted in higher scores obtained by the taught group in eight out of nine OSCE stations.

Finally, Celebi et al conducted a randomised controlled crossover study assessing the effect of a 1-week training module on drug-related problems.17 Seventy-four year-5 medical students participated in a seminar on prescription errors, a prescribing exercise using both paper cases and real patients, and discussions with a lecturer. Following the training module, rates of potential prescription errors were reduced from 69% to 29% (p<0.001). Together, these four educational interventions resulted in students having an increased sense of knowledge and comfort in taking a medication history, a higher rate of error-free prescriptions and superior performance in clinical examinations. None of the interventions, however, consisted of an online module, nor did they address medication safety as a wide-ranging issue.

It is imperative to consider basic learning styles in order to maximise knowledge acquisition especially for medical students where a high burden of information is often presented. Every student has a unique learning style and with the meshing hypothesis, which states that instruction is best provided in a format that matches the preference style of the learner.18 The Fleming and Mills’ VARK model describes the four modes of learning which focus on visual, auditory, reading and kinesthetic learning styles.18 Visual learners learn predominantly through seeing and they often prefer visual displays, diagrams and video demonstrations.18 Auditory learners learn through listening and they often prefer verbal lectures, discussions and sometimes even background music.18 Readers learn and prefer when information is displayed as words, and they often prefer manuals, reports and essays.18 Kinesthetic learners learn through movement and they often prefer hands-on exercises.18 Thus, with different learning styles, different educational interventions may be used to maximise knowledge acquisition for medical students.

The educational intervention in this study addresses medication safety on the whole, and covers issues relating to obtaining accurate histories, writing clear and rational prescriptions, avoiding common prescribing pitfalls, learning the risks associated with dangerous abbreviations and high-risk medications, following hospital protocols, drug monitoring concepts, accessing drug information, and reporting AEs. The aim of this study was to evaluate the effect of an online educational module on medical students’ knowledge of medication safety.