Healthy survivor effect -Reply

[William McCabe <WMCCABE@tnrcc.state.tx.us>]

Thanks for your response, Bill.  I've seen many of the studies regarding 
healthy workers and their effect on epidemiological studies, especially
those with weak associations.  What prompted my question was its
application to the A-bomb survivors (hence my use of "healthy survivor"
vs. "healthy worker").  It seems like such a stretch to me to apply this
effect so well documented in workers to A-bomb survivors, but this may
be due to my lack of information.   It seems to me that the populations,
assumptions about the universe, etc., etc. for worker and A-bomb
survivor are not the same.

Does anybody have any information explaining, justifying, or supporting
application of the "healthy survivor" (not healthy worker) effect to the
A-bomb survivors or is it a hypothesis at this point riding on the coattails
of the "healthy worker effect"?

Thanks.

William J. McCabe
Health Physicist, MC-131
Texas Natural Resource Conservation Commission
P.O. Box 13087
Austin, Texas  78711-3087
wmccabe@tnrcc.state.tx.us
(512) 239-2252     fax: (512)239-6362

>>> "R. William Field" <bill-field@uiowa.edu> 20 May 98  10:42 >>>
Mr. McCabe,

A colleague forwarded your message to me.  I am no longer a member of
the
radsafe listserv.  Please feel free to share this information with the
listserv if you would like.  I am responding to your query concerning the
Healthy Worker Effect (HWE).  

The HWE is very real.  It was actually documented over 100 years ago.  I
can cite several hundred studies where it played a large role in the
findings.  Workers on average are healthier than the general population
and
have a lower disease rate.  General population subgroups are not ideal
comparison groups for studying risks from occupational exposures. 
People
selected for employment are generally healthier than the general
population
and once they are employed they have a better economic condition and
better
access to medical care than the general population.  Workers also make
lifestyle changes that are conducive to better health.  In analyses of
exposure response patterns in an occupational study, the HWE often
attenuates an adverse effect of exposure.  This attenuation is more
problematic when examining weak associations.  

Two good references:

Wen et al. Anatomy of the healthy worker effect: a critical review, J.
Occup. Med 25:283-89, 1983    

The evolving concept of the healthy worker survivor effect, Epidemiology
5(2):189-196, 1994.

Regards, Bill Field


>Can anyone point me to articles/studies discussing the "healthy survivor
>effect" and whether it is real or not?

>William J. McCabe
>Health Physicist, MC-131


******************************
R. William Field, Ph.D.
Division of Epidemiology
Department of Preventive Medicine
  and Environmental Health
N222 Oakdale Hall
University of Iowa
Iowa City, Iowa 52242
319-335-4413 (phone)
319-335-4747 (fax)
mailto:bill-field@uiowa.edu
******************************