Medication errors

Medication errors refer to any unintended consequences arising in the medication use process, regardless of whether an injury transpired or whether the potential for injury was present (11)(12). These include mistakes in prescribing, dispensing, and/or administering medication, as well as patient adherence. Most definitions of patient safety and medication errors recognise that organisational factors interact with human factors to facilitate and mitigate medication-related

Table 1.2: Examples of medication errors adopted from Black et al (14)

Miscommunication of drug orders due to poor handwriting, confusion between drugs with similar names, misuse of zeroes and decimal points, confusion of metric and other dosing units, and inappropriate abbreviations

Inappropriate drug selection due to incomplete patient data such as contraindications, drug interactions, known allergies, current and previous diagnoses, current and previous therapies, and test results

Miscalculation of drug dosage due to incorrect selection of route of administration, mistakes with frequency or infusion rates

Out-of-date drug information, for example, in reference to alerts, warnings, or information on newly approved drugs

Monitoring failures due to laboratory test results and drug administration monitoring not considered

Inappropriate drug selection due to clinical incompetence

Estimating the true incidence of medication-related errors can be problematic due to the various definitions and methodologies used to detect or measure their occurrence. In addition, many are never discovered, acknowledged, or reported (15). Medication errors in hospitals are highly underreported if healthcare professionals perceive no harm to the patient or the incident is not considered significant enough to report (16)(17)(18)(19).

Prescribing and drug administration processes have traditionally been recognised as accounting for the greatest proportion of all medication errors, independent of whether harm is caused (20)(21)(22)(23)(24). Lewis et al conducted a systematic review in 2009 on the prevalence, incidence, and nature of prescribing errors in hospital inpatients and reviewed 65 studies mostly from the United States of America (USA) and the United Kingdom (UK) (25). These studies excluded ePrescribing systems. They reported a median prescription error rate of seven percent with incorrect dosage being the most common error.

Another systematic review by Ross et al in 2009 reviewed 24 studies of non-consultant hospital doctors (NCHDs) and reported an error rate of two to 514 per 1000 items prescribed and four percent to 82% of patient prescription charts reviewed (26). A more recent prospective study by Ashcroft et al in 2015 on the prevalence, nature, severity, and risk factors for prescribing errors in 20 UK

hospitals found a mean error rate of nine percent (27). Error rates for doctors in training were significantly higher than medical consultants and prescribing errors were 70% more likely to occur at the time of hospital admission (27).

The transition between hospital and community settings is prone to medication errors due to incomplete medication records, lack of communication between healthcare providers, missed patient follow-up, inadequate patient education, and the absence of patient involvement in the medicines management process (28). ‘Medication reconciliation’ performed by nurses, doctors, or pharmacy staff at hospital admission, on the wards, and at transfer and discharge to primary care is an effective strategy for reducing medication errors (29). Researchers have found hospital pharmacists are uniquely positioned to lead and support patients and inter-professional teams with medication reconciliation based on their education and expertise in medicines management (30) resulting in better accuracy and improved clinical and economic outcomes (31)(32)(33)(34)(35)(36). However, this three step process of verifying medication use, identifying variances, and rectifying medication errors at interfaces of care is not provided by pharmacy staff in all hospitals, is limited to within pharmacy opening hours, and is dependent on staff compliments. For example, a survey by Stein et al in 2015 reviewing pharmacy involvement in hospital medication reconciliation programmes across the USA found a mere 53% of hospitals had dedicated pharmacy staff to perform medication reconciliation (37). Barriers include cost, time, inadequate staffing, unreliable patient information, lack of programme ownership by a particular discipline, and difficulty relaying information between hospital and outpatient settings (38).

These inefficiencies highlight the need for electronic systems for medicines management.

Systematic reviews of medication administration error prevalence in healthcare settings found their occurrence common (39)(40)(41), with an estimated median of 19% of ‘total opportunities for error’ in hospitals (39). Specific to causes of medication administration errors in the hospital setting, a systematic review by Keers et al in 2013 identified 54 studies and found error-provoking conditions influencing administration errors included inadequate written communication

medicines supply and storage relating to pharmacy dispensing errors and ward stock management; high workload; and concerns with ward-based equipment with access and functionality (42). Other issues included patient availability and acuity; staff fatigue and stress; and interruptions and distractions during drug administration (42). The above systematic reviews found ePrescribing and a closed loop ePrescribing, electronic dispensing, and electronic administration system may improve the prescribing process (39)(40)(42).

A review of the literature on the incidence of dispensing errors by James et al in 2009 identified 60 papers and found dispensing errors in hospital pharmacy ranged between 0.02–2.7% (43). A systematic review of the nature of dispensing errors in hospital pharmacies by Aldhwaihi et al in 2016 identified 15 studies with the most frequent errors reported pertaining to dispensing the incorrect medicine, strength, and dosage form (44). The most common factors associated with dispensing errors included high workload; low staffing; mix-up of look-alike/sound-alike drugs; lack of knowledge and experience; distractions and interruptions; and communication problems within the dispensary team (44).

In an Irish context, a collaborative study of medication safety in four Irish hospitals by Kirke et al in 2007 found prescribing was responsible for approximately 50% of overall incident/near miss reports, dispensing 10%, and administration 30% (45). The remaining incidents/near misses included ordering and monitoring of drugs. More recently the first national report on the frequency and nature of adverse events in hospitals in Ireland by Rafter et al in 2016 found the third leading category of adverse events was medication-related (46). These findings were similar to other international studies (47)(48)(49). The Institute of Medicine further estimate at least one medication error per hospital patient occurs each day (50) which would potentially equate to over three million medication errors in Irish public hospitals every year (51).

Medication errors are common, costly, and an important source of iatrogenic harm (14). Detailed analysis and classification of errors in medicines management suggest prevention strategies targeting systems rather than individuals are more likely to prove effective in reducing error rates (24).