Multidisciplinary Delphi study validated variables for calculating cost of medication errors in the Sri Lankan context

Introduction The burden of medication errors needs to be costed but no standard method, nor a standard list of variables, has yet been identified. Hence, this study aimed to establish a standard list of cost variables (SLCV) for calculating the cost of medication errors in Sri Lanka from a provider perspective. Methods The study had three discrete phases: a systematic review to identify cost variables used globally to calculate the cost of medication errors (published), followed by a Delphi study with 18 experts to assess appropriateness, accuracy, accessibility and measurability of identified cost variables. Finally, a hospital bill analysis was done to assess accessibility and measurability of cost variables. Results In Delphi round 1, out of 13 cost variables, nine were retained as appropriate for calculating medication error costs. None were rated as accessible or measurable in the healthcare settings in Sri Lanka. Experts highlighted the need for a guideline to use the cost variables, which was then developed and shared among experts in Delphi round 2. The SLCV, including eight variables, was retained as appropriate for calculating medication error cost after Delphi round 2. Thirty-one bills confirmed the accessibility and measurability of most variables in SLCV. Conclusion A standard list comprising eight appropriate cost variables to calculate the cost of medication errors, and a guideline was developed for Sri Lanka. The accessibility of these variables was affirmed through a bill audit.