Discussion
In our study, our team observed a good number of medication discrepancies, more than half (73.5%) of which were likely to cause patients moderate to significant discomfort or clinical deterioration. These results endorsed that clinical pharmacists are crucial in both detection and avoidance of medication errors and consistent to the findings of earlier studies on pharmacists’ positive role in medication reconciliation[2-4], and also a recent systematic review demonstrated that medication reconciliation performed by pharmacist was effective in reducing medication discrepancies[21]. In addition, our study further supported the role of pharmacist trainees for obtaining medication histories. Moreover, as far as we know, this is the first study to explore the prevalence and risk factors for UMDs and involve clinical pharmacist trainees in the medication reconciliation procedure in China.
Our results found that 22.4% of study patients experienced one or more UMDs between physician admission medication orders and a BPMH; this result is in line with the earlier studies, which revealed UMD rate of between 8.1% and 53.6% in various clinical settings[4, 19, 22]. These high rates of UMD at admission highlight the importance of close monitoring on drug treatment plan at transitions. And these differences of the UMD rate may because of the various study designs, clinical settings and studied patients. We also found that more than half of these UMDs involved medications belongs to the ATC class C (cardiovascular system) (53.0%), which is also consistent with findings of previous studies[4, 23].
The most frequent type of UMD in our study was the omission of home medications (40.8%), followed by incorrect dose (20.5%), which is in accordance with previous research findings[4, 24]. While most of medication omissions were unlikely to cause severe discomfort or clinical deterioration, however, patient clinical consequences of related errors may be more disastrous in some cases. For example, one of the potential severe medication errors identified in our study was omission of warfarin in a patient with valvular atrial fibrillation and cerebral infarction. It is well known that doctors have difficulty in obtaining an accurate and through medication history on hospital admission and pharmacists are more competent than doctors in this field[12], which is also verified by our study.
Our study showed that 73.5% of UMDs were evaluated to be prone to cause moderate to severe discomfort or clinical deterioration. We applied the same approach to assess clinical impact as Cornish PL et al[19] that firstly developed the method to evaluate the potential damage of medication discrepancy at transitions. However, previous studies have identified a wide range of UMDs at the rate of 10% up to 68% which were likely to cause moderate to severe potential damage to patients[4, 23-25]. Our results are higher than that of previous studies possibly because cardiovascular drugs were responsible for more than half of all these which were more likely to cause significant damage than other kind of drugs. Besides comparing clinical impact between different studies is challenging due to the considerable variability and subjectivity in methods of evaluation of clinical impact. The potentially severe nature of some UMDs emphasizes the importance of conducting medication reconciliation within 48 hours after hospital admission.
There are different results from earlier studies on risk factors for UMDs at admission. In our study, 2 or more chronic diseases at admission and 5 or more drugs on the BMPH were identified as independent predictors of UMDs. Our study found a 3.25-fold higher risk in patients receiving more than 5 drugs at hospital admission compared with 3.03-4.7 -fold in other studies[2, 26]. While other studies also reported a correlation between unintentional discrepancies and the number of medications at hospital admission[4, 23]. Besides that, our study identified 2 or more chronic diseases as predictors of UMDs, while Pardo-Cabello AJ et al[27] identified a Charlson Comorbidity score ≥2 as a predictive factor for UMDs which is not as convenient as our predictor.
None of the sociodemographic variables (i.e. age, sex, educational level, or living alone) investigated in the current study were correlated with the presence of UMDs at admission, in line with previous studies[4, 28]. However, unlike previous studies[29, 30], admitting physician experience was not an independent risk factor for medication reconciliation errors at admission. Perhaps because that overwhelming majority of our study patients were admitted by interns, which is very common in China that intern and junior doctors generally take charge of medication history collection work due to the shortage of medical staff and overhospitalization.
Our findings have underlined the significance of accurate medication reconciliation conducted by a pharmacist in diminishing medication discrepancy errors and promoting patient safety at hospital admission. We would like to vigorously promote the application of a systematic medication reconciliation procedure in our hospital and other hospitals in China as well as the participation of clinical pharmacists in conducting this process by the WHO High 5s protocol at transitions. We are aware that not all Chinese hospitals have a certificated clinical pharmacist to perform the medication reconciliation process[31], therefore we would recommend that strictly trained pharmacists shall participate this task.
This study has some important limitations. Firstly, it was conducted at a single teaching hospital on a limited sample size of patients admitted to four medicine units due to the shortage of clinical pharmacists. Other departments may have different rates of UMDs. Secondly, the categorization of unintentional medication discrepancies into medication errors was partially based on subjective judgment from expert panel and is accordingly subject to bias. Thirdly, our clinical harm evaluation for UMDs was ‘potential’ harm rated by expert panel and the actual harm of errors prevented is unclear. It’s hard to know the effect of pharmaceutical interventions on medical outcomes since the eligible patients were not followed beyond the study.