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Safe Medication Practices - March 2001

Benchmarking Medication Error Rates

A significant percentage of medical errors occurring in our healthcare community are due to medication errors. As in the U.S., Australia and the United Kingdom, medication errors have imposed a serious threat to patient safety, and have become a major public health issue in Canada. As institutions and healthcare providers are paying increased attention to this concern, one of the frequently asked questions and sought answer is: "What is our medication error rate, and how does it compared with others?"

The benchmarking question is often raised because many continue to believe that "error rate" is a measure of patient safety. The reality is, that the medication error rate determination is derived from most, if not all, reported incidents. Kenneth Barker's study on error rates, presented at the American Society of Hospital Pharmacists’ Clinical Meeting in Las Vegas, December 2000, showed that medication error rates captured by incident reports is the least effective and least reliable determinant of the true error rate. 1

The number of medication errors will vary, depending very much on the vigor with which errors are identified and reported. Although most hospitals have a relatively standardized method for defining a medication incident (a medication error that reaches a patient), the manner in which they are detected, and reported, differ vastly.

Simply counting "numbers" and comparing statistics of medication errors lacks validity, and more importantly can dangerously undermine efforts towards full reporting and learning. A "high error rate" when comparing numbers within an organization or externally, can mean there are unsafe medication practices, or it could reflect an organizational culture which promotes error reporting and learning. Conversely, a ‘low error rate’ might suggest a successful error prevention program, or may be the result of an inherent punitive approach which in turn, inhibits individuals from reporting errors and analyzing causes of errors. Hospitals which focus their attention on maintaining a "low error rate", will inadvertently promote an unproductive cycle of underreporting of errors and will therefore, allow unrecognized weaknesses in the medication use system to continue. Low error rates often result in false sense of security and an implicit acceptance of preventable errors. A hospital's strategy needs to place less emphasis on comparing error rates (or ‘benchmarking’), and more emphasis on open reporting, full disclosure and identifying areas for system improvement and safeguards. This is also referred to as encouraging a "Culture of Safety’.

How then, do we measure the safety of medication use and the effectiveness of error prevention strategies within an organization? According to Michael Cohen, co-founder and president of ISMP (US), analyzing the causes of actual incidents and near-misses and implementing changes to address these causes, and then measuring the outcomes of the changes, is an effective and more meaningful way to gauge error prevention efforts. ISMP has recently developed and implemented The Medication Safety Self-Assessment tool. Many hospitals in the US have participated in the effort to measure, whether or not, basic recommendations for safe medication practices have been incorporated into their hospital's medication use system

The Medication Safety Self-Assessment is divided into the 10 elements that most significantly influence safe medication use. Each element is defined by one or more core distinguishing characteristics of a safe medication system. Representative self-assessment characteristics are provided to help hospitals evaluate their success with each of the core distinguishing characteristics. Most of the characteristics included in the tool represent system improvements that ISMP has recommended in response to analysis of medication errors reported; or problems identified during on-site consultations with hospitals. Many of the characteristics of ‘safe medication systems" are evidence-based and extracted from medication error studies.

The Medication Safety Self Assessment's 10 elements are listed below:

  1. Patient Information
  2. Drug Information
  3. Communication of Drug Orders and Other Drug Information
  4. Drug labeling, Packaging and Nomenclature
  5. Drug Standardization, Storage, and Distribution
  6. Medication Delivery and Device Acquisition, Use and Monitoring
  7. Environmental Factors
  8. Staff Competency and Education
  9. Patient Education
  10. Quality Processes and Risk Management

Hospital’s self-assessment data are weighted in accordance with a weighted scoring system developed by ISMP. The scoring of the responses assists the hospital in identifying the top priority areas for system improvements.

ISMP Canada is in the process of adapting the Medication Safety Self-Assessment tool for Canadian hospitals, and plans to offer Canadian hospitals the opportunity to perform self-assessments of their medication safety. ISMP Canada is committed to furthering medication safety efforts in Canada.


  1. Barker, Kenneth, et al. "Comparison of Methods for Detecting Medication Errors in 36 Hospitals and Skilled-nursing Facilities". Presented at ASHP Midyear Clinical Meeting, Las Vegas, December 2000.
  2. ISMP Medication Safety Alert! Vol. 3, issue 18, September 9, 1998