Google Answers Logo
View Question
Q: clinical trials ( Answered 1 out of 5 stars,   5 Comments )
Subject: clinical trials
Category: Science
Asked by: dubon-ga
List Price: $200.00
Posted: 15 Jul 2004 20:54 PDT
Expires: 14 Aug 2004 20:54 PDT
Question ID: 374774
the number of clinical trials and irb

Request for Question Clarification by nancylynn-ga on 16 Jul 2004 13:46 PDT
There are over 41,000 *registered* clinical trials currently underway,
world-wide. I can provide you with resources for learning more about
these trials, including centerwatch (as noted by purkinje-ga), and
information on how the trials process works.

I can also look for resources pertaining to non-registered trials.
(Recently, there have been demands from medical organizations that ALL
clinical trials be listed on a national registry.)

Regarding the IRB, do you mean you want information on the IRB's role
in clinical trials? I can also located information on how clinical
trials are regulated outside the U.S.

I just want to check that I'm on the correct path with this criteria.
Is this the sort of information you need?

Thanks for any clarification.

Best regards,
Google Answers Researcher
Subject: Re: clinical trials
Answered By: nancylynn-ga on 17 Jul 2004 20:10 PDT
Rated:1 out of 5 stars
The total number of trials, worldwide, can't be quantified precisely.

The Thomson Corporation maintains the aforementioned, very
comprehensive site, "Center Watch":

Center Watch estimates that over 41,000 medical trials (which include
medical devices, drug efficacy, quality of life, and other types of
trials) are currently underway; that is, *known* trials: trials that
are registered with regulatory agencies and/or medical organizations.

The best estimate I can give you on IRBs is 4,000-6,000, discussed in
the section on IRBs, below.

That estimate on trials, 41,000+, appears to be the best estimate,
based on my research. (I can call Thomson on Monday to verify that
that number is for *global* trials; that is how I'm interpreting it )

Some trials aren't registered with any agency in any country, so it's
impossible to be certain just what the exact total is. For instance,
some drug companies don't make their clinical trials known until the
trial has ended. (And, they may not report the trial at all, if the
results were disappointing.)

As noted in this July 23, 2003 report published in the JAMA (Journal
of the American Medical Association), "Registering Clinical Trials,"
written by Kay Dickersin, PhD, MA, and Drummond Rennie, MD:
"That it is not possible to find information about all initiated
clinical trials is of international concern. This is a particular
worry because scientists tend to publish their positive findings more
often than their negative findings (publication bias). A comprehensive
register of initiated clinical trials, with each trial assigned a
unique identifier, would inform reviewers, physicians, and others (eg,
consumers) about which trials had been started and directly address
the problem of publication bias. . . ."

This concern has prompted several high profile organizations to demand
that all trials be made public: This past June the International
Committee of Medical Journal Editors urged pharmaceutical companies to
release more information regarding their clinical trials, while the
American Medical Association (AMA) called for a "public registry" of
all clinical trials.
See: the Jun 15 2004 edition of Health Day:
(Scroll down to header "Drugmakers May Have to Publicly Register Clinical Trials.")

And on April 2, 2004, the World Health Organization (WHO) announced
that WHO "and Current Controlled Trials (CCT) have announced that,
from today, all randomized controlled trials approved by the WHO
ethics review board will be assigned an International Standard
Randomised Controlled Trial Number (ISRCTN).1 As a result, the
scientific community should now find it easier to keep up-to-date with
current research" from 192 countries. See the press release "WHO leads
drive for international coordination of clinical research":

Check out "Current Controlled-Trials" at
At right center on that page go to "CT metaRegister of Controlled
Trials (mRCT) International database combining registers of ongoing
randomised controlled trials in all areas of healthcare" and click on
"Click To Enter,"
to bring up:
At left, see mRCT's FAQ:
See "Is the mRCT a complete record of trials around the world?"
"The mRCT is not a comprehensive record of all randomised trials
worldwide. It is therefore wise to search other sites (for example
those in 'Links' section) to complement the information in the mRCT."
At "Links":
You'll see a directory listing trials by category and, as you scroll
down that page, you'll see links to various agencies, institutes,
universities, and drug companies currently conducting trials all over
the world.

But counting those links won't give you a true total, as many of those
organizations have more than one trial in-progress, and some links to
lead to databases of every known trial underway for a specific

So, the best we can do for now is to rely on the best estimates made
by organizations that track trials. As noted, Center Watch estimates
41,000 plus worldwide. For a *very rough* sampling of how that all
breaks down:

The article "Active Clinical Trials Worldwide (Phase I-III)," from the
Products In Development journal (published by Barnett), notes that
"More than 3,000 clinical trials (Phase I, II, or III) are taking
place worldwide, according to a March 2003 analysis of data reported
by the three major pharmaceutical pipeline databases--Adis R&D Insight
(Adis International Limited), IMS R&D Focus (IMSworld Publications
Ltd), and Pharmaprojects (PJB Publications) (as searchable on The
Dialog Corporation).
. . . ."
But note that that total of 3,000 refers only to pharmaceutical trials.

(Btw, the Dialog Corporation, noted above, is owned by Thomson
Corporation. That reference is to Dialog's Adis Clinical Trials
Insight" section:
Drug Development Pipeline:

Fletcher Allen Health Care (Fletcher Allen is an "academic medical
center" affiliated with the University of Vermont College of
Medicine,) reports that 1,800 cancer studies are currently in-progress
at the National Cancer Institute (NCI):

You can also check out "Clinical Trials" site, which is maintained by the NIH:
" currently contains approximately 11,000 clinical
studies [though presumably, some of them are closed]sponsored by the
National Institutes of Health, other federal agencies, and private
industry." (You can check the database at that site, which includes
trials from "all 50 States and in over 90 countries.") lists studies by institute, such as NIH, the
National Eye Institute (NEI), National Institute of Mental Health,
(NIMH), the Veterans Administration, and the National Cancer Institute

Other Resources:

Also see Yahoo's Directory of Clinical Trials:

Google's directory:

And, the Society for Clinical Trials:

Back at Center Watch:
You can check for specific studies according to specialty: cardiac,
gastroenterology, obstetrics/gynecology, oncology, etc., as this page:

That same page has links to studies being conducted by the National
Cancer Institute and by National Institute for Health (NIH).

At the "Additional Resources for Patients" page:
Scoll down to see a long list of international organizations currently
conducting research.


Thomson's Centerwatch also lists trials taking place worldwide:
(I count about 1,560 clinical trials currently underway outside the U.S.)

At that page see links to global research centers, and to
international "providers" who assist in conducting clinical trials,
including adherence to regulatory/ethical (IRB) guidelines:
For one example, check out Origin Pharmaceutical Services, which is
based in Oxford, England:  

IRB (Institutional Review Board) & Other Regulatory:

Per my RFC, I'm assuming you wanted to know about the role of IRBs? If
you want to know how many IRBs there are, well, that, too, is up for

The best estimate -- in fact, the only estimate -- I could find is
4,000-6,000 in the U.S. That's the number mentioned in this Sept. 12,
2002 transcript from a meeting of the President's Council on
" 'Again, it seems to me it is hard to know whether the system is
better, worse, going in the right direction, going in the wrong
direction, if you don't systematically, regularly, routinely even know
how many people are on research trials. We don't even know how much we
spend on it. I might say we don't even know exactly how many IRBs
there are. I am sure General Motors knows exactly to the number how
many dealerships it has. We know that there's somewhere between 4,000
and 6,000 IRBs in this country.' "
That statement was made by Ezekiel J. Emanuel, M.D., Ph.D. Chief,
Center for Clinical Bioethics, National Institutes of Health.

You can also check the U.S. Deparment of Health & Human Services" page on IRBs:  
To search by location or institution name, but I couldn't find totals.

As to the role of IRBs: these are independent consulting companies
that review clinical trials to ensure the welfare of study
For instance, to oversee medical devices:

See "Guidance for Institutional Review Boards and Clinical Investigators
(1998 Update)":

From the FDA's IRB FAQ:
"1. What is an Institutional Review Board (IRB)? 
Under FDA regulations, an IRB is an appropriately constituted group
that has been formally designated to review and monitor biomedical
research involving human subjects. In accordance with FDA regulations,
an IRB has the authority to approve, require modifications in (to
secure approval), or disapprove research. This group review serves an
important role in the protection of the rights and welfare of human
research subjects. . . .
"2. Do IRBs have to be formally called by that name? 
No, 'IRB' is a generic term used by FDA (and HHS) to refer to a group
whose function is to review research to assure the protection of the
rights and welfare of the human subjects. Each institution may use
whatever name it chooses. Regardless of the name chosen, the IRB is
subject to the Agency's IRB regulations when studies of FDA regulated
products are reviewed and approved."

Examples of IRB consulting groups:
Schulman Associates' Institutional Review Board:
"Schulman Associates Institutional Review Board, Inc. ('SAIRB' or the
'Board') is an independent IRB that has more than 20 years of
experience in reviewing research protocols and consent forms to
evaluate compliance with all relevant regulations. As an independent
IRB, SAIRB is not part of an institution such as an academic medical
center or research hospital. Working with a network of regional
consultants, the Board can provide IRB services for national
multi-site studies . . . ."


Independent Review Consulting, Inc. (IRC):

In addition, universities and hospitals that conduct clinical trials
have their own IRBs. For example Georgetown University:

Changes Re: Clinical Trials in the EU:

As of May 2004, clinical trials are regulated in the EU, under the "EU
Clinical Trial Directive":
 "Directive 2001/20/EC of the European Parliament and of the Council
on the approximation of the laws, regulations and administrative
provisions of the Member States relating to the implementation of good
clinical practice in clinical trials":

Trials will be registered here:
So, keep checking back at that site.

This May 2001 paper, "Review of the European Union Clinical Trial
Directive," by Biologics Consulting, discusses IRB/ethics issues in
the EU.
Scroll down to "Article 3:  Protection of Clinical Trial Subjects." 

Search Strings:

estimate number clinical trials worldwide
number clinical trials worldwide
"total number" AND "clinical trials"
medical trials worldwide
international clinical trials
FDA clinical trials
"World Health Organization" AND "clinical trials"
Europe AND regulate AND "clinical trials"
EU clinical trials
IRB EU clinical trials
how many IRBs 
how many IRBs international

I hope my research is of help to you. If you require clarification, or
need help navigating any of the above links, please post a "Request
For Clarification," PRIOR to rating my answer.

Best regards,
Google Answers Researcher

Request for Answer Clarification by dubon-ga on 02 Aug 2004 09:57 PDT
the answer is completely unstaisfactory. while there are many
references, it confuses trials and IRBs. and finally, there is not
reall answer. Please clarify the VERY confusin answer you sent me, or
I shall have to dispute the charge,. As of now, the answer is

Clarification of Answer by nancylynn-ga on 02 Aug 2004 14:56 PDT

Yes, I know my answer is confusing. It's confusing because no one
knows exactly how many clinical trials are ongoing throughout the
country, or the world. That's why I tried to give you as many
resources as possible - - this is essentially a jigsaw puzzle and I
figured the more pieces you had . . . .

As I noted, JAMA, the AMA, and  the International Committee of Medical
Journal Editors have recently demanded that an international registry
be created so that ALL medical trials will be known and recorded.
Let's hope that happens soon.

I called CenterWatch, which monitors registered trials worldwide
(including FDA trials), and research analyst Stephen DeSantis told me
CenterWatch's estimate of 41,000 trials means 41,000 *known* trials
*worldwide*; that is trials "that are in Phases I -- III. Not
pre-clinical or post-marketing" around the globe.

CenterWatch estimates that approximately 30,000 clinical trials
(that's medicine; that figure doesn't include medical devices) are
currently underway in the U.S., "but that number changes every day."

So, 41,000 clinical trials globally; 30,000 clinical trials in the
U.S. are the  best known estimates.

As for IRBs, DeSantis estimates "under 500," in the U.S., with 500
being at the high end of that estimate.

The IRB industry has only been in existence for about 10-15 years old
and isn't stringently regulated. According to CenterWatch, many IRBs
are small and go in and out of business and, at this point, it's
extremely difficult to estimate how many there are.

Compare CenterWatch's estimate to the one I quoted, in my answer, from
Dr. Emanuel at NIH (Emanuel made a "guesstimate" of 4,000-6,000, which
CenterWatch feels is way off), and you can see why there's so much
confusion regarding IRBs.

Google Answers Researcher
dubon-ga rated this answer:1 out of 5 stars

Subject: Re: clinical trials
From: purkinje-ga on 15 Jul 2004 22:13 PDT
Hi, there are approximately 1000 drugs in clinical trials. I could
spend more time and find the exact number, but you can do that too--
go to for FDA trials. By IRB do you mean institutional
review board? I'm not sure what you're asking. Hope that helps.
Subject: Re: clinical trials
From: purkinje-ga on 18 Jul 2004 14:42 PDT
1000, 41000, what's the difference?? Ha ha. That's what I get for
guessing. I should have spent the time looking up the info. I thought
I knew! Ya' can learn something everyday.
Subject: Re: clinical trials
From: naveen1-ga on 27 Aug 2004 08:23 PDT
The actual number of clinical trials is less than 14000. You can count
the numbers from this website.
Subject: Re: clinical trials
From: nancylynn-ga on 28 Aug 2004 08:12 PDT

I did note the resource in my answer. 

Again, there are several sources that list clinical trials; however,
CenterWatch is the *most comprehensive* source.

I can't emphasize this enough: the exact number of trials in the U.S.,
and worldwide, is unknown because many trials are never registered
with any agency.

For anyone interested in this topic please read my "Answer Clarification."
Subject: Re: clinical trials
From: medicaldeviceman-ga on 09 Mar 2005 17:57 PST
You might want to check out this site as well:

They have various links to sites on clinical trials.  

Hope that helps!

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy