Setting
A large teaching hospital in South London, providing secondary, tertiary and quarternary services. Up until 2012, almost all discharge prescriptions were written by doctors. DTTAs require validation by pharmacists before …show more content…
All DTTAs written in May 2009 were retrieved. Pharmacists’ corrections prior to dispensing were noted by reviewing annotations on the paper copies and information from the electronic patient record (EPR). Clarifications to facilitate dispensing, because a medication was non-formulary or to provide extra administration instructions, were excluded.
To detect errors in PTTAs, a power calculation determined that a sample size of 500 PTTAs would be sufficient to observe an error rate similar to that found in DTTAs. Using proportionate allocation, we calculated numbers needed to ensure adequate representation of each clinical specialty in the sample. Data was collected on several convenient days between October 2013 and April 2014, until the pre-determined sample sizes for every specialty were achieved. Every weekday was represented. On each data collection day, researchers collected final (paper and electronic) versions of PTTAs written a week earlier. They compared the documented medication histories, inpatient drug charts and discharge prescriptions for congruency. Using patient records and their own clinical expertise, senior clinical pharmacists reviewed discrepancies to determine which were intentional and unintentional (errors). Where necessary, the pharmacist who wrote the TTA was asked the reason for the apparent discrepancy. …show more content…
The DTTAs studied were written before EPMA was introduced, while the PTTAs examined were all written after implementation of EPMA. We believe that the reduction in errors is unlikely to be due to EPMA – from our (pharmacy’s) routine monitoring of prescribing errors we know that the errors noted in the 2009 DTTAs are still seen. Other studies have found little or no improvement in errors at discharge with electronic prescribing systems [3,8]. The constraints of the workflow process meant that it was not possible to check the PTTAs immediately after they were written, therefore corrections made by doctors and dispensary staff will not have been detected. However, pharmacists report rarely being contacted about mistakes on their TTAs. In fact, one reason for conducting the study was because the lack of feedback made pharmacists concerned that doctors were not checking the PTTAs before authorizing them. The undetected errors would have to be several orders of magnitude higher than our findings for this to significantly affect the results. Our method for reviewing PTTAs matched the process pharmacists use when validating DTTAs. Therefore, while it is possible that some errors in PTTAs may not have been recorded, we do not believe that this will have significantly affected the