Observations from Working Group Exercises

The Twenty-eighth Annual Meeting of Representatives of the National Centres participating in the WHO Programme for International Drug Monitoring was held from 26 to 29 September 2005, in Geneva, Switzerland. In this meeting, working group exercises focused on several key issues in pharmacovigilance including:

• how pharmacovigilance centres react to high profile (drug) withdrawals
• pharmacovigilance in public health programmes
• reporting adverse events following immunization (AEFI)
• reporting and learning from patient safety events
• developing an international taxonomy for patient safety events
• the relevance of the International Classification of Diseases (ICD) in pharmacovigilance.

In the previous issue of the newsletter we summarized the discussions from the first three of these exercises. We now report the key conclusions from the remaining three:

Reporting and learning from patient safety events

The World Health Assembly in 2002 urged member countries to focus on patient safety. Pharmacovigilance (PV) centres currently focus mainly on drug safety issues and are often questioned as to how effective these actions have been in ensuring patient safety. Generally, people are aware that medication errors do occur; however, they may not make the connection that pharmacovigilance centres already provide a system to monitor and analyse the occurrence of these errors. Understanding this link would help to understand the role of PV centres in promoting health care, with the patient as the ultimate beneficiary. The working group agreed that there is a necessity to have a system in place to escalate local reports of medication errors to an international level, so that signals can be identified and strategies and remedial actions implemented in a global sense.

In placing the focus on patient safety, there is a need to:

• make a clear distinction between medication errors and adverse drug reactions;
• develop a standardized system to collect and collate reports of medication errors;
• standardize key words in order to facilitate effective analysis of collected data.

Existing adverse drug reaction (ADR) reporting forms/systems in countries may not be suitable for capturing data on medication errors. In addition, getting reports on medication errors could be difficult due to medicolegal implications. Patients have to be educated to take responsibility for their medications, whilst emphasizing that unavoidable ADRs can and will occur. A thorough analysis would identify possible root causes for the reported errors. Strategies would have to be developed and implemented to minimize recurrence of errors. It must be realized that the greater focus on patient safety, with all its implications, would entail expansion and extension of the current services and functions of the national pharmacovigilance centres.

The working group concluded that it is best to commission a pilot project of a limited number of countries, to study the feasibility for pharmacovigilance centres to shift the focus on to patient safety, with the particular emphasis on capturing medication errors and not only restricted to collecting ADR reports. As a first step, the WHO Collaborating Centre for International Drug Monitoring in Uppsala, Sweden could produce a draft protocol for the study and may concentrate on a particular area, e.g. parenteral infusions. Several countries have expressed a strong interest in participating in the pilot study to investigate the role of pharmacovigilance centres in promoting patient safety.

Developing an International Taxonomy for Patient Safety

Growing concerns among a number of countries about patient safety have led WHO to call for a concerted international effort to understand and prevent adverse events in health care. At present the studies and incident monitoring systems that report patient safety data, with a few exceptions, differ in the way they define, count, and track adverse events. The lack of standardized nomenclature and taxonomy for patient safety events have confounded the development of appropriate and sustainable solutions to the many patient safety related problems. In order to facilitate the global exchange and dissemination of information among users of incident reporting systems, it is necessary to adopt a common patient safety terminology and to collect standardized patient safety data that are conducive to processing and classification. The working group arrived at the opinion that the United States Joint Commission on Accreditation of Healthcare Organizations' (JCAHO’s) scheme for Patient Safety Event Taxonomy can serve as a starting point. The group examined the five primary categories: impact, type, domain, cause, and prevention and mitigation and, agreed that further categories may be needed for developing countries. The group considered that a patient safety event taxonomy should be incident rather than patient based. It was noted that a patient safety event taxonomy goes beyond, and is broader than, medication adverse events. It covers policy and practice, procedures and everything that happens to the patient. The group concluded that an International Patient Safety Event Taxonomy (IPSET) will enhance pharmacovigilance activities and promote patient safety worldwide and recommended that this be developed.

The relevance of the WHO Classification systems (in particular, the International Classification of Diseases, ICD) in pharmacovigilance

Several national centres participating in the WHO Programme for International Drug Monitoring use ICD-10 or 9 for recording indications and concomitant morbidity. However, there are limitations to the use of the ICD. It cannot be used to code ADRs as it is not suitable for symptoms, the section for drugs (Y40-59) is not compatible with the Anatomical, Therapeutic, Chemical (ATC) classification and special indications, e.g. anaesthesia, cannot be coded.

Suggestions from the workshop were as follows:

• An ICD drug classification should be compatible with the ATC if it is to be used.

• For special indications the UMC should assign temporary codes and negotiate new codes with the ICD team on behalf of national centres.

• Temporary codes should be integrated into Vigibase Online.

• A mapping exercise should be undertaken to identify common elements. There should be mapping between WHO-adverse reaction terminology (WHO-ART) and ICD 10/11.

As a related recommendation, the group stated that since industry codes are in MedDRA (medical dictionary for regulatory activities) and most national centres use WHO-ART (WHO adverse reaction terminology), a backmapping of WHO-ART to MedDRA would be useful to avoid manual re-coding by national centres.