Study looks at whether greater care might be needed in selecting essential medicines

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Study looks at whether greater care might be needed in selecting essential medicines

Toronto, June 3, 2019

By Anna Wassermann

Dr. Nav Persaud
Dr. Nav Persaud

A new study by Dr. Nav Persaud, published in the June issue of the World Health Organization Bulletin, aims to inform essential medicines lists in support of universal health coverage.

Dr. Persaud, a scientist at the MAP Centre for Urban Health Solutions and staff physician in the Department of Family and Community Medicine at St. Michael’s Hospital, researches how to address health inequities through the development of high-quality evidence. We connected with Dr. Persaud to learn more about his recent research.

Can you describe the importance of essential medicines lists?

Essential medicines lists help to determine the medicines available to five billion people; they’re intended to include medicines that meet the priority health care needs of populations. Governments and health care institutions use essential medicines lists to determine which medicines to fund, stock, prescribe and dispense.

What did you set out to study?

We set out to compare the medicines prioritized in different countries. Our aim was to compare the medicines included in national essential medicine lists with the World Health Organization’s (WHO) model list to understand patterns and identify opportunities for improvement.

Why compare essential medicines lists between countries?

Countries must select medicines for their essential medicines lists appropriately in order to facilitate sustainable, equitable access to medicines and promote their appropriate use. Since a country’s essential medicines list is intended to meet the needs of its population, countries that are geographically close or similar to each other in size, health care expenditure, and health status might be expected to have similar essential medicines lists. Differences between essential medicines lists that are not explained by country characteristics may represent opportunities for improving certain countries’ lists.

What did you find when you compared essential medicines lists?

We found a large number of differences between lists; much more than we had expected. We identified 137 national essential medicines lists that collectively included 2,068 medicines at least once. Each national essential medicines list contained 44 to 983 medicines, and the number of differences between each country’s essential medicines list and the WHO model essential medicines list ranged from 93 to 815. Most medicines were listed by fewer than 10 per cent of countries.

Can you identify any reasons for these differences?

Despite what many would have expected, the basic characteristics of countries like region and size of economy do not explain the differences in essential medicines lists. Further research may identify explanations such as differences in the processes for selecting medicines.

Where do you see this research heading?

This work and future related work may help identify opportunities to improve essential medicines lists and promote appropriate use of medicines in support of universal health coverage. Some of the included medicines have been withdrawn in many countries due to harmful effects. Each country can now easily see how its essential medicines list differs from its peers when looking for medicines to add or remove, by visiting

This paper is an example of how St. Michael's Hospital is making Ontario Healthier, Wealthier, Smarter.

About St. Michael's Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

About Unity Health Toronto

Unity Health Toronto, comprised of Providence Healthcare, St. Joseph’s Health Centre and St. Michael’s Hospital, works to advance the health of everyone in our urban communities and beyond. Our health network serves patients, residents and clients across the full spectrum of care, spanning primary care, secondary community care, tertiary and quaternary care services to post-acute through rehabilitation, palliative care and long-term care, while investing in world-class research and education. For more information, visit

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