Medication Discrepancies Case Studies

Data Synthesis

Admission

Medication discrepancies are common on admission and account for up to 20% of all ADEs experienced at the time of hospitalisation. While studies have reported on discrepancies without explaining if they were intentional (clinically justifiable) or unintentional (done in error) discrepancies.2,3,20 For the purposes of this literature review, discrepancies include both types, unless otherwise stated. Inadvertent discontinuation of a serious nature on admission to hospital occurs in approximately 6% of patients and is a common source of error on admission.21 Numerous studies that have investigated medication discrepancies during admission at different hospital settings (acute care unit2,22, internal medicine department21,

In a systematic review (22 studies, 3755 patients) Tam et al. concluded that unintentional discrepancies in prescription medication histories occurred in up to 67% of admissions.4

Adverse events can occur if there is an unintended discrepancy between the patient’s actual medication history and the medications ordered in the hospital.8 Studies which assessed the discrepancies identified in terms of their potential impact on clinical outcomes varied in their definitions of categories of severity, making comparisons difficult. A commonly used rating scale was the 3-point scale used by Cornish et al25: “unlikely to cause discomfort or clinical deterioration,” “potential to cause moderate discomfort or clinical deterioration,” and “potential to result in severe discomfort or clinical deterioration.” For the purposes of this literature review, the term clinically significant applies to any identified medication discrepancy with the potential for moderate or severe harm. Studies which have included a

Some authors have pointed out that half of the medication errors may be generated in processes associated with changes in health care level,22,24,27 particularly where there is no routine practice of medication reconciliation. In studies where initial medication histories were compared with reconciled histories, a high proportion of errors with medication histories at admission were observed where medication reconciliation was not undertaken,22,23,26 reinforcing admission as a critical point of care. A systematic review of studies of medication discrepancies on hospital admission indicated that 60%–67% of prescription medication histories contained at least one error, either the omission of a medication being taken by the patient or the reporting of a medication not being taken. An estimated 11%–59% of these errors were deemed clinically significant.4 However, there is considerable variation in defining medication history errors at admission. Although unintentional omission of a medication is the most common form of discrepancy, few studies have included only omission errors, 28,29 most studies evaluating the prevalence of medication