Procedure to update and disseminate the WHO Model List of Essential Medicines1
Document EB109/8 (Annex), 7 Dec 2001
1. The Model List is drawn up by the WHO Expert Committee on the Use of Essential Drugs, following the Regulations for Expert Advisory Panels and Committees2. Since 1977 the Expert Committee has been convened every two years, but could meet more often if needed.
2. The Expert Committee comprises eight to 12 members drawn from the WHO Expert Advisory Panels3 for Drug Evaluation and for Drug Policies and Management, and, where appropriate and in consultation with the relevant cluster, from other expert advisory panels. Expert Committee members are selected by the Director-General to represent a wide range of geographical and professional backgrounds, including clinical pharmacology, clinical medicine, international public health, guideline development methodology, systematic literature search methods, risk-assessment and cost-effectiveness analysis.
3. Meetings of the Expert Committee are private2 and members are required to complete a WHO declaration of interest form before the meeting. Observers may be invited in accordance with Regulations for Expert Advisory Panels and Committees to attend all or parts of the meetings of the Expert Committee. Patient advocacy groups and representatives of the health care industry are invited to comment on the applications and draft recommendations (see below), but are not invited to attend decision-making parts of meetings of the Expert Committee.
4. Applications for inclusions, changes or deletions to the Model List are submitted by or through relevant departments in WHO to the secretary of the Expert Committee. The opinion of the relevant department in WHO is conveyed to the secretary with the application and is presented to the Expert Committee. The information that should be submitted with the application is summarized in Box 1. The application should be received at least four months before the meeting of the Expert Committee. For therapeutic categories for which no specific department exists in WHO the application can be submitted by the department of Essential drugs and medicines policy.
5. The step-wise approach for reviewing applications and draft recommendations is summarized in Box 2. A similar process is used periodically to review whole sections of the Model List. In that case the need for review and the selection of the reviewer(s) are considered in close collaboration with the relevant department in WHO.
Criteria for selection4
6. The choice of essential medicines depends on several factors, including the disease burden and sound and adequate data on the efficacy, safety and comparative cost-effectiveness of available treatments. Stability in various conditions, the need for special diagnostic or treatment facilities and pharmacokinetic properties are also considered if appropriate. When adequate scientific evidence is not available on current treatment of a priority disease, the Expert Committee may either defer the issue until more evidence becomes available, or choose to make recommendations based on expert opinion and experience.
7. Most essential medicines should be formulated as single compounds. Fixed-ratio combination products are selected only when the combination has a proven advantage in therapeutic effect, safety or compliance over single compounds administered separately. Examples of combination medicines that have met these criteria include new formulations for tuberculosis and malaria.
8. In cost comparisons between medicines, the cost of the total treatment, and not only the unit cost of the medicine, is considered. Cost and cost-effectiveness comparisons may be made among alternative treatments within the same therapeutic group, but will generally not be made across therapeutic categories (for example, between treatment of tuberculosis and treatment of malaria). The absolute cost of the treatment will not constitute a reason to exclude a medicine from the Model List that otherwise meets the stated selected criteria. The patent status of a medicine is not considered in selecting medicines for the Model List.
9. In adapting the WHO Model List to national needs, countries often consider factors such as local demography and pattern of diseases; treatment facilities; training and experience of the available personnel; local availability of individual pharmaceutical products; financial resources; and environmental factors.
10. In its report the Expert Committee summarizes the reasons for each recommendation with reference to the underlying evidence. The Expert Committee may grade its recommendations depending on the nature of the underlying evidence. When insufficient evidence is available, the Expert Committee specifies that its recommendations are based on expert opinion and experience. The Committee's report also refers to existing standard clinical guidelines. The Expert Committee may specifically indicate in the list medicines for which specialized health care facilities may be needed or which meet all the selection criteria and which are cost-effective within their therapeutic group, but which are not necessarily affordable for all health systems.
11. Presentation of the Model List will be recommended by the Expert Committee based on considerations of clarity and practicality. Previous model lists have been presented in various formats, including one in which medicines considered to be in the main list appear first under each therapeutic group, followed by medicines considered to be in a complementary list.
12. Immediately after the meeting and subject to final approval by the Director-General, the recommended changes to the Model List, the summary of the Expert Committee's considerations and other relevant information are posted on the WHO web site. The full report of the meeting is published in the WHO Technical Report Series. Translations of the report are published as soon as possible and in close collaboration with WHO regional offices.
13. In addition to the information on whether a medicine is in the Model List or not, it is important for end-users to have access to information that supports the selection, such as summaries of relevant WHO clinical guidelines, the most important systematic reviews, important references and indicative cost information. Other information is also linked to the medicines in the Model List such as the WHO Model Formulary and information on nomenclature and quality-assurance standards. All this information is presented on the WHO web site as the "WHO essential medicines library" (see figure) intended to facilitate the work of national committees.
 As part of the revised procedure for updating the Model List, the term "essential medicines" is used in preference to "essential drugs". This reflects the common use of the term "medicines" to describe pharmaceutical preparations used in clinical health care practice.
 Since the first meeting of the Expert Committee in 1977, criteria for selection of essential medicines have focused on disease prevalence, treatment facilities, safety, efficacy, quality, availability, and cost factors. Descriptions of selection criteria appear in the Ninth Report of the WHO Expert Committee on the Use of Essential Drugs (WHO Technical Report Series, No. 895, 2000), the Eighth Report of the WHO Expert Committee on the Use of Essential Drugs (WHO Technical Report Series, No. 882, 1998), and previous reports of the Committee.
See also the Essential Medicines Library