ASCHER AND SCHECHTER
By John Lauritsen
Rethinking AIDS May 1993
have recently appeared that claim to refute Peter Duesberg's risk-AlDS
hypothesis on the basis of cohort studies. One, by M.S. Ascher
et al., rebukes Duesberg in the final paragraph: "The energies
of Duesberg and his followers could better be applied to unraveling
the enigmatic mechanism of the HIV pathogenesis of AIDS"
(M.S. Ascher et al., "Does drug use cause AIDS?", Nature,
11 March 1993).
by Martin T. Schechter et al., also rebukes Duesberg in the final
paragraph: "It is a disservice to the many people infected
with HIV-1 and a hindrance to public health initiatives for scientists
to claim that HIV-1 is harmless and not aetiologically related to
AIDS" (Martin T. Schechter et al., "HIV-1 and the aetiology
of AIDS," Lancet, 13 March 1993).
are forms of survey research, my profession since 1966. In a letter
to me (14 April 1993), Martin Schechter denies this, which merely
indicates his ignorance of basic concepts. In survey research, data
from a selected sample are projected to represent a greater universe
or population. As explained in one of the classic texts of my field:
as probably everyone knows, arises from the impossibility or impracticability
of studying an entire population. It is not very feasible, if at
all possible, to study the entire population of the United States
at a given time, nor is it necessary to test the entire contents
of a well-sifted grain barrel to determine its quality content.
Even where it is advisable to study an entire population, time and
cost elements are usually prohibitive. Essentially. sampling is
a problem in inference, the aim being to secure sufficient
information from a representative segment of the population to enable
one to infer the true state of affairs with respect to the
characteristics under observation for the entire population within
a certain range of error." (Robert Ferb, Statistical Techniques
in Market Research, New York, 1949)
claim to support the HIV-AIDS hypothesis. Both studies are highly
implausible, if for no other reason, because they show that drugs
don't do anything. But drugs are not sugar pills, and there are
physical consequences to putting them in human bodies.
the two brief reports, I had grave doubts that the researchers understood
how to design, conduct, or analyze survey research. I wrote to Ascher
and Schechter, asking permission to look at raw data, questionnaires,
and other study materials. Ascher did not reply. Schechter wrote:
your request to inspect our raw data and other documents is problematic.
As you are no doubt aware, there are tremendous concerns surrounding
confidentiality in studies of this type. In our informed consent,
we have specifically promised not only all the participants but
their practitioners that the data we collect will not be seen by
any individuals or agencies outside the investigators involved in
the study. To allow anyone else to inspect the raw data would constitute
a breach of this fundamental promise."
the most specific request I made in my letter: a copy of the self-administered
questionnaire he mentioned in his article. I fail to see how the
release of a blank questionnaire or of data, consisting of grouped
numbers, could violate promises of confidentiality. Apparently
Schechter expects us to accept his research on faith.
One of the
cardinal principles of science is openness, which means sharing
data and describing methodology in sufficient detail that a study
could be replicated or in some other way verified. Although
replication might not be possible or practical, there is another
way the worth of the data could be evaluated through validation.
survey research, it is the practice to validate all studies, using
sophisticated techniques. Let's suppose that an in-person survey
was conducted by local interviewers in a dozen cities around the
country. After the questionnaires have come back from the field,
interviewers from the home office, using WATS lines, validate a
percentage of each interviewer's work. This means calling respondents
and asking a few questions designed to ascertain that the rules
of the study were followed. If even a single questionnaire fails
the validation test, then validation is performed upon 100% of that
interviewer's work. In the extremely rare event that cheating is
discovered, the culprits are severely punished.
survey has little or no credibility. Since neither the Ascher nor
the Schechter study is even open to validation, they deserve to
be rejected on this basis alone. In addition, neither author describes
the characteristics of the samples, so one has no idea how representative
they might be of the populations from which they were allegedly
It has been
my experience as an analyst, without exception, that when data don't
make sense it is because there is something wrong with them. It
doesn't make sense that a single, biochemically inactive microbe
could be the cause of the 29 (at last count) AIDS-indicator diseases.
And it doesn't make sense that drugs don't do anything.