CIOMS (Council for International Organizations of Medical Sciences)

Who writes the consensus before it becomes the rule?

In one sentence

CIOMS is the Geneva council of medical science bodies whose expert working groups write the consensus that pharmacovigilance rules are built on.

Set up by the World Health Organization (WHO) and the United Nations Educational, Scientific and Cultural Organization (UNESCO) in 1949, it is a non-governmental, non-profit association of medical societies, academies and research councils. Since 1986 its numbered working groups, experts from regulators, industry and academia, have produced the reporting form, the periodic report, signal detection and risk minimisation; several guidelines of the International Council for Harmonisation (ICH) were based on them.

Where it sits

ParentsThe WHO and UNESCO, which set it up in 1949
MembersMedical societies, academies and research councils, in three membership classes
CouncilCIOMS: a non-governmental, non-profit association with its Secretariat in Geneva
Working groupsNumbered expert groups, I to XVII, most of them on pharmacovigilanceReports with no legal force, taken up by the ICH and the regulators

Think of it like this

Think of chefs from rival kitchens agreeing on how a recipe should be written down. No kitchen is bound to the format, yet the cookbooks end up using it.

Key insights

Set up by the WHO and UNESCOWorking groups, not a mandateThe form the world copiedStill at work

The Council for International Organizations of Medical Sciences (CIOMS) was constituted in Brussels in 1949 by the WHO and UNESCO to coordinate medical congresses, and took its present name in 1952. It represents the biomedical community through its member organisations, and its mission is to advance public health through guidance on health research: ethics, medical product development and safety.

Its working groups bring together experts from academia, industry and regulators, and patients where the topic calls for it. Each publishes a consensus report, free to download. The groups have no legal jurisdiction or mandate; other bodies, the ICH first among them, write the recommendations into their frameworks. CIOMS has been an official ICH observer since June 2016.

Its first pharmacovigilance group, set up in 1986, devised standardised definitions, procedures and a format for manufacturers reporting reactions across borders. Its Form I set the minimum standard for a case report for the first time and became the basis of many national forms. ICH E2A, E2C, E2D and E2F were based on CIOMS work. Chapter 2 shows which report wrote the standard for your task.

Working Group XIV published its report on artificial intelligence in pharmacovigilance on 4 December 2025. Working Group XVI, meeting since February 2025, is updating the Development Safety Update Report; Working Group XVII takes up long-term safety. A cumulative glossary of the definitions from past reports is kept as a living document.

Jump to: 1 Three moments 2 Your study, their standard 3 What the network adds to the law 4 Test yourself

Chapter 1

Which three moments made CIOMS what it is?

Pick a year. Each turned a meeting of scientists into a standard.

1949A council of congresses1990The form2016Ethics, and a seat at the ICH

A council of congresses

In 1948 UNESCO asked the WHO about a body to coordinate international medical congresses. In 1949 a jointly sponsored conference in Brussels constituted the council as a non-governmental organisation, funded by its two parents. As its work widened, the name changed in 1952 to the Council for International Organizations of Medical Sciences.

In March 1959 it convened a meeting in Vienna on the principles and scope of controlled clinical trials, chaired by Austin Bradford Hill; the council calls it a methodological landmark. In 1977 a CIOMS conference recommended that the council be an independent forum for companies and regulators, convening expert groups when needed.

What it left behind: a neutral room, owned by scientists, where regulators and companies could sit together.

The form

In 1986 CIOMS set up its first working group on pharmacovigilance, on the international reporting of adverse drug reactions: how a manufacturer should report a reaction seen in one country to the regulators of the other countries where the drug is sold. The group devised standardised definitions, procedures and a format. Its Form I set the minimum standard for a report for the first time, and many national reporting forms were later built on it. The initial report came in 1987, the final one in 1990.

A series followed: Working Group II on periodic safety update summaries in 1992, core clinical safety information in 1995, benefit-risk for marketed drugs in 1998, safety information from clinical trials in 2005, the development safety update report in 2006, signal detection in 2010. Several ICH guidelines, E2A, E2C, E2D and E2F among them, were based on that work.

What it left behind: the case report as a form, and a numbered series the field still cites by Roman numeral.

Ethics, and a seat at the ICH

CIOMS had written international ethical guidelines for research with human subjects with the WHO since 1982, revised in 1993 and 2002 and used widely in low-resource countries. In 2016 it published the International Ethical Guidelines for Health-related Research Involving Humans, again with the WHO: research must have scientific and social value, and the text sets rules for low-resource settings, vulnerable groups, and the use of biological samples and health data.

The same year, in June, CIOMS became an official observer at the ICH, the body that turns its consensus into guidelines regulators adopt. The groups kept coming: patient involvement in 2022, benefit-risk balance in 2025, artificial intelligence in pharmacovigilance on 4 December 2025.

What it left behind: a council that writes the ethics of a study and sits, without a vote, where its safety work becomes the rule.

Chapter 2

Your study, their standard

A safety task is in front of you. Two questions decide which CIOMS report wrote the standard for it: is the medicine in trials or on the market, and is it one case or a pattern? Pick a cell.

In trialsOn the marketOne caseCase, in trialsCase, on the marketA patternPattern, in trialsPattern, on the market

Or it is not a case at all: a known risk to reduce or a study with people in it

While a medicine is in trials, Working Group VI’s report, Management of Safety Information from Clinical Trials (2005), is the CIOMS standard for how a sponsor collects, assesses and communicates what happens to participants. CIOMS Working Group VI, 2005

On the market, the single case has a form. Working Group I, set up in 1986 for reactions seen in one country and owed to the regulators of the others, devised standardised definitions, procedures and a format. Its Form I set the minimum standard for the first time and became the basis of many national forms; the final report came in 1990. CIOMS Working Group I, 1990

A pattern across a development programme goes into the Development Safety Update Report (DSUR). Working Group VII harmonised its format and content in 2006, and ICH E2F described it further; Working Group XVI, meeting since February 2025, is updating it so the report shows benefit and risk together, not safety alone. CIOMS Working Group VII, 2006; Working Group XVI

A pattern on the market is a signal. Working Group VIII’s Practical Aspects of Signal Detection in Pharmacovigilance (2010) is the consensus on finding and handling one, and Working Group IV (1998) had already set out how a signal is weighed against benefit for a marketed drug. CIOMS Working Groups VIII, 2010, and IV, 1998

When the risk is known and must be reduced, Working Group IX’s Practical Approaches to Risk Minimisation for Medicinal Products (2014) is the reference; the 2025 report on the benefit-risk balance of medicinal products continues the line. CIOMS Working Group IX, 2014; CIOMS, 2025

A study with people in it answers to the International Ethical Guidelines for Health-related Research Involving Humans, prepared with the WHO and published in 2016: scientific and social value, research in low-resource settings, vulnerable groups, and the use of samples and health data. CIOMS and WHO, 2016

As the CIOMS working groups have no legal jurisdiction or mandate to make binding decisions, reliance is placed on other bodies to incorporate the CIOMS recommendations, guidelines or good practices into a regulatory or legislative framework.
CIOMS, Our History

The next sentence names the body: the ICH serves as a good example. Several ICH guidelines were based on CIOMS work, and since June 2016 the council sits at the ICH as an observer.

Chapter 3

What does the network add to the law?

Nothing CIOMS writes binds anyone. Five places where its consensus became the rule anyway.

	The law	CIOMS
The case report	A national reporting form for each regulator	Form I, 1990: the minimum standard many of those forms were built on
The periodic report	ICH E2C and E2F, implemented by the regulators	Working Groups II (1992) and VII (2006), the work those guidelines were based on
The signal	Each regulator’s own guidance on signal management	Working Group VIII, 2010: the practical consensus on detecting one
Who sits at the table	Regulators, and at the ICH the industry	Academia, industry, regulators and, by topic, patients; an ICH observer since June 2016
The ethics of a study	National ethics committees and their rules	International ethical guidelines with the WHO, revised in 2016, used widely in low-resource countries

Show the references

The case report: CIOMS, Pharmacovigilance, History.
The periodic report: CIOMS, Pharmacovigilance, Results; CIOMS Working Group XVI page.
The signal: CIOMS, Pharmacovigilance, Results.
Who sits at the table: CIOMS, About; CIOMS, Our History.
The ethics of a study: CIOMS, Bioethics.

CIOMS cannot bind anyone. It writes the consensus first, and the rules follow.

The facts, in one place

What it is	An international, non-governmental, non-profit organisation of medical science bodies, established jointly by the WHO and UNESCO in 1949 to advance public health through guidance on health research, ethics, product development and safety.
Since	1949, constituted in Brussels as a council to coordinate international medical congresses; the present name since 1952.
Who decides	A General Assembly of all members, once a year, by consensus; an Executive Committee of up to twelve, which appoints the Secretary-General.
Seat	Geneva, where the Secretariat works and the statutes were registered in 2021.
Members	International, national and associate members: the World Medical Association, the International Society of Pharmacovigilance and national academies and research councils among them.
Working groups	Experts from academia, industry and regulators; each publishes a free consensus report after about three years. Current: XIV on artificial intelligence (report December 2025), XVI on the development safety update report, XVII on long-term safety.
With the ICH	Official observer since June 2016; E2A, E2C, E2D and E2F were based on CIOMS work; CIOMS keeps a glossary of ICH terms.

Don’t confuse it with: the ICH

CIOMS

The consensus

Is: a council of medical science bodies, set up by the WHO and UNESCO, run from Geneva
Decides: nothing that binds; its working groups publish consensus reports
Example: Form I, the case report the national forms copied

ICH

The guideline

Is: an association of regulators and industry, under Swiss law since 2015
Decides: guidelines adopted by its Assembly and implemented by each regulator
Example: E2D, the post-approval case definitions, based on CIOMS work

Chapter 4

Test yourself

Myth or Truth? Pick an answer to see the explanation.

“A CIOMS working group report binds companies once it is published.”

MythTruth

MythYou got it.Not quite.

The groups have no legal jurisdiction or mandate. A report binds no one until another body, the ICH or a regulator, writes it into a guideline or a law.

“The CIOMS Form I was the basis for many national adverse reaction reporting forms.”