I got a little curious about who these folks are. Note that
I have no idea whether or not they are legitimate. From
everything I've read it appears they have good, honorable
intentions.  But you should be aware of what they might do
with your personal data.  I apologize for the lengthy post,
but a good deal of the space is quotations from the web
site.

The following is from
http://www.worldhealthsurvey.com/terms.php:

"Our Service
ODS[*] provides users with the ability to
1. complete a survey form and/or
2. agree to participate in a clinical drug trial (the
Service).
By posting your information with ODS, you agree that ODS may
release your contact information and all information that
you supplied in the survey form to clinical trial companies.
You also agree that ODS may release all information that you
supplied in the survey form, exclusing contact information,
to pharmaceutical companies, universities, non-profit
agencies and government agencies expressing an interest in
the information you have provided. Unless explicitly stated
otherwise, any new features or services offered pursuant to
this web site are subject to these TOS."

ODS is Online Data Services Ltd.  They are doing business as
worldhealthsurvey.com.  Further down the same page we find

"Use of Content
Except as expressly authorized by ODS or advertisers, you
agree not to modify, rent, lease, loan, sell, distribute or
create derivative works based on the Service or its content,
in whole or in part.

With respect to Content you elect to post with ODS, you
grant ODS the royalty-free, perpetual, irrevocable,
non-exclusive and fully sub-licensable right and license to
use, reproduce, modify, adapt, publish, translate, create
derivative works from, distribute, perform and display such
Content (in whole or part) world wide and/or to incorporate
it in other works in any form, media, or technology now
known or later developed. You agree not to access the
Service by any means other than through the interface that
is provided by ODS for use in accessing the Service."

Finally, here's part of their privacy policy (from
http://www.worldhealthsurvey.com/privacy.php):

"How ODS Discloses Your Personal Information

ODS will only disclose any personally identifiable
information about individual users, in accordance with this
Privacy Policy and the Terms of Service, or to comply with
applicable laws or valid legal process, or to protect the
rights or property of ODS.

The data you provide us with on the survey, excluding
personally identifiable information, may be supplied, at the
sole discretion of ODS, to pharmaceutical or other
health-related businesses, for the purpose of statistical
data gathering.

We disclose personally identifiable individual information
and the other information you provide us to clinical trial
companies who declare that they are interested in
considering you for participation in a clinical drug trial.
The clinical trial company may or may not contact you for
inclusion in a particular study, at their sole discretion.
We cannot guarantee that the personally identifiable
individual information you submit to us will not end up in
the hands of pharmaceutical companies.

We may also disclose your contact information and the other
information that you provide us in the following
circumstances:

1. We may permit third parties to offer you services or
goods if we think that you will benefit from the offer. You
will be able to tell when another business is involved in
your transactions. We will share your contact information
only with such third parties.

2. We may employ other companies and individuals to perform
functions on our behalf. They may have access to personal
information needed to perform their functions, but will not
be able to legally use it for other purposes.

3. We might change, sell, reorganize or liquidate via
bankruptcy this business. If we do, your information will of
course be one of the transferred assets.

4. We may release account and other personal information
when we believe release is appropriate to comply with law,
to enforce or apply our Terms of Service and other
agreements; or to protect the rights, property, or safety of
ODS, our users, or others. This may include exchanging
information with other companies and organizations for fraud
protection and credit risk reduction.

Other than as set out above, you will receive notice when
information about you might go to third parties, and you
will have an opportunity to choose not to share the
information."