Medication Incident Operational Definitions

  1. This measure aims to answer the question:
    ‘How often is a patient harmed due to an error in the process of treatment with medication?’This therefore, does not include events where the patient had an unexpected adverse drug reaction but no error occurred. Currently information on Medication Incidents (MI) is available in most hospitals through an incident reporting system (e.g. Datix, Safeguard). This is a self-reporting system and it is well recognised that reporting rates vary between hospitals and within different areas of the same hospital. Whilst it is known that a significant number of MIs are not reported, it is currently not possible in most institutions to determine what percentage of MIs are reported and what percentage are not reported. However, where significant harm occurs as a result of a MI, the probability that this will be reported is likely to be much greater. A ‘healthy’ incident reporting system is one where overall reporting levels are high, but the percentage of incidents reported with significant harm is low. The US National Coordinating Council for Medication Error Reporting and Prevention (MERPsee appendix 1) provides a very useful standardised method of categorising MIs, in particular with regards to the severity of any harm which may have occurred (levels E – I).
  2. Data to report to MiST
  • Percentage of reported MIs in the combined MERP levels [A – D] and [E – I]
  • Percentage of reported MIs in each MERP level (A – I)
  • Number of reported MIs per calendar month
  • Where possible, a breakdown of reported MIs should be provided, reported as a percentage of the total reported, in the following categories (see appendix 2):
    • Prescribing errors/incidents
    • Administration errors/incidents
    • Other errors/incidents

Where available, data should be submitted separately as Whole Hospital data (including PICU) and Paediatric Intensive Care Unit data

We have developed a reporting tool which has the added benefit of interpreting some of your local data for you: MERP Datasheet v1.0

We request that data is submitted to MiST quarterly – click here to submit your data.

Note on denominator data:

At present, there is no requirement to submit denominator data. This is for a number of reasons. Firstly, when considering MIs the best denominator to use is the number of administered drug doses/infusions, but this is not routinely collected in most, if any institutions. Patient bed days can be used as a substitute, but institutions vary in the intensity and severity of illness they manage, and organisations with a PICU for example will have a much medication usage per patient bed day. Secondly, as noted above MI data as collected from incident reporting systems is extremely variable since it is entirely reporter dependent. Therefore, differences in MI rates (as determined by number of MIs divided by a defined denominator) are more likely to reflect differences in reporting than they are actual true number of MIs. Finally, the purpose of MiST is not to benchmark institutions, but to share data and methods of good practice. Therefore, by not using a denominator, direct comparisons between institutions will not be possible and the tendency to benchmark will be avoided. Rather, organisations can use submitted data to monitor trends within their own institution, and those organisations with low levels of significant harm (as determined by percentage of reported MIs in the combined MERP level [E – I]) can be encouraged to share insights into their safety culture and methods used to achieve this.

More Information (including full definitions and examples of classification can be found in the full document: MiST MI Operational Definitions)