Canada Uses AHRQ Research to Prevent Medication Errors

Patient Safety
October 2006

AHRQ-supported research was influential in revisions to Health Canada's process for approving names for drugs. The research conducted by Bruce Lambert, PhD, Professor, Department of Pharmacy Administration at the University of Illinois at Chicago, focused on how auditory perception of sound-alike names can lead to medication errors.

Prior to implementation of this revised process for approving drug names, proposed product names were evaluated on a case-by-case basis. The new process is expected to avoid confusion between products, reduce the likelihood of medication mix-ups, and improve patient safety in the context of day-to-day use of products.

Lambert was an invited lecturer at Health Canada's Look-Alike/Sound-Alike Health Product Names Consultative Workshop in October 2003. Government officials, health care professionals, and organizations representing patient and consumer groups attended the workshop, which addressed safety concerns related to look-alike/sound-alike product names.

"This research provides valuable insight on the impact product names have on patient safety," said Michele Chadwick, Manager, Special Initiatives Unit, Policy and Promotion Division, Centre for Policy and Regulatory Affairs, Biologics and Genetic Therapies Directorate and workshop chair. "That information and discussions I had with Dr. Lambert significantly contributed to the policy recommendations that were made following the meeting."

Lambert described his research that showed how similarity increases the risk of drug confusion errors. These errors can occur in visual perception, auditory perception, and short-term memory. Workshop participants reviewed Lambert's research on the frequency and similarity of many "neighborhoods" of drug names. A drug neighborhood is a group of drugs with similar spellings, pronunciations, or therapeutic uses that increase the potential for confusion.

Lambert's early research, which built upon research conducted by Paul Luce at the University of Buffalo, demonstrated that the probability of incorrect visual perception depends on several characteristics of the drug name. The most notable of these include the prescribing frequency of a drug and the number of other drug names in a particular drug's neighborhood.

As might be expected, more errors occur with drugs that have a greater number of visually similar neighbors than those with fewer neighboring names. An example of a confusing (or "dense") neighborhood of drugs includes Dynabac, Synalar, Rynatan, Dynacirc, and Dynacin. An example of a less confusing (or low density) neighborhood of drugs is the one containing only Flexeril, which has no identified neighbors.

Furthermore, product similarities (e.g., dosage strength, formulation, or dosing schedule) increase the possibility of drug name confusion. Notably, commonly prescribed drugs are recognized more accurately than rarely prescribed ones.

Lambert's research on visual neighborhoods was extended by his later research on auditory perception. That research demonstrated that drug names with a greater number of phonetic neighbors and with more commonly prescribed phonetic neighbors had higher error rates. His research also showed that auditory perception errors increase as the background level of conversational noise increases.

Health Canada's policy recommendations based, in part, on the workshop were made in March 2004, with implementation beginning in the fall of 2006. Under the new premarketing policy, Canadian drug manufacturers will now be required to submit a name analysis for new products to demonstrate that the proposed name is not similar to other product names. Manufacturers are given the option of providing a prioritized list of name choices, should the first-choice name be unacceptable for safety reasons.

A guidance document has been developed to assist the Canadian drug industry in complying with the new process. The use of a computer program to analyze product names during the approval process is also being considered, and policies for post-marketing surveillance are under development.

The Health Products and Food Branch (HPFB) within Health Canada is the Canadian government agency with a scope and mission similar to that of the U.S. Food and Drug Administration. Specifically, HPFB's mandate is to take an integrated approach to managing the health-related risks and benefits of health products and food. HPFB does this by: 

  1. Minimizing health risk factors to Canadians while maximizing the safety provided by the regulatory system for health products and food. 
  2. Promoting conditions that enable Canadians to make healthy choices and providing information to aid in making informed health decisions.
Impact Case Study Identifier: 
AHRQ Product(s): Research
Topics(s): Patient Safety, Prescription Drugs
Geographic Location: Canada
Implementer: Health Canada
Date: 10/01/2006

Lambert BL, Chang KY, Gupta P. Effects of frequency and similarity neighborhoods on pharmacists' visual perception of drug names. Soc Sci Med 2003;57:1939-55.

Lambert BL, Chang KY, Lin SJ. Effect of orthographic and phonological similarity on false recognition of drug names. Soc Sci Med 2001;52(12):1843-57.

Lambert BL, Lin SJ, Tan H. Designing safe drug names. Drug Safety 2005;28(6):495-512.

Page last reviewed October 2014