Evaluation of a weight-based process for real-time accurate confirmation of oral liquid controlled drug balances

To meet legislative requirements in Australia, the balance of controlled drugs (CDs) must be confirmed after completion of each transaction. This is particularly challenging for liquid CD formulations, and over the years, health organisations have implemented various methods of performing this task, including the use of visual aids or conversion of bulk formulations to individual unit doses. These methods have a number of limitations. Therefore, this study aimed to evaluate the accuracy and feasibility of a weight-based method for confirming oral liquid CD balances packed in multidose containers. This study was conducted in a palliative care ward of a metropolitan hospital over a 41-day period. Morphine mixture 5 mg/1 mL transactions and balance checks were confirmed using weight calculations of the product bottle. The weights were then converted to volume using a locally developed electronic application, which was recorded in the relevant CD registers. The acceptable tolerance per transaction (±0.1 mL) was determined prior to commencement based on 80 test transactions. Throughout the trial period, 407 transactions were undertaken, among which there were no CD discrepancies. Nine nurses provided feedback via an anonymous online survey after the trial, mostly reporting that the new method was more accurate. However, participants also reported that it took on average 3 min longer to complete each transaction. In conclusion, utilising a weight-based method of confirming liquid CD balances may present a feasible method of meeting legislative requirements related to the recording and accountability of CDs. This project was exempt due to the local policy requirements that constitute research by the Eastern Health Office of Research and Ethics (Reference no: QA24-100-111698). The justification for this ethics exemption was as follows: the study conformed with the National Health and Medical Research Council (NHMRC) Ethical considerations in quality assurance and evaluation activities and did not directly affect patient care; written consent was not required from participants per local requirements, however staff were provided verbal and written project information and were informed their participation in the survey was voluntary and anonymous.