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The following document is the major issues and changes resulting from
the JSM'98 Panel Discussion.
You are invited to read it and join the discussion
on it.
Power Analysis and Other Prerequisites to Valid and Humane Statistical
Studies
Regarding human subjects protection (HSP), Nancy Berman, Ph.D., GCRC
Statistician at the Harbor-UCLA Medical Center, noted that power analyses
are required to justify the practical value of the research and the number
of sample animals to be used in research on animals. This leads her to
recommend power analysis or, where that may not be feasible, some similarly
strong justification to justify experimentation on human beings. There
should be strong evidence that the research is capable of producing valid
results before human beings (or animals) are put at risk. Furthermore,
the sample sizes should be large enough to yield valid results, but not
so large as to place excessive numbers of subjects at risk unnecessarily.
Carolin M. Frey of the Penn State Geisinger Health System recommends use
of "prospective power analysis or the planned precision of the study endpoint
with consideration given to the feasibility of obtaining subjects and the
value of the data elements to be collected."
Others have commented on the tendency to protect only against Type I
error (false positives) in hypothesis testing generally and have recommended
power analysis in all statistical studies in order to protect against Type
II error (false negatives) as well. The ethical issues may extend beyond
HSP to include avoidance of wasting dollar and talent resources on statistical
studies that could be foreseen to be invalid. The originally circulated
draft of the guidelines attempted to include such considerations under
the relatively simple but broad rubric of seeking practically significant
results, not just statistically significant results. A recommendation for
power analysis or similar justification could be usefully included both
under the heading of Professionalism and under the heading Responsibilities
to Research Subjects.
One could extend this principle more generally to deal with Tukey's
admonition to take some time to understand data sets rather than rushing
to run definitive statistical tests against them. John Bailar has cautioned,
however, that ad hoc EDA can sometimes represent a "fishing expedition"
such that an unorganized researcher simply reports on whatever happens
to show some apparent statistical significance after extensive playing
around with numerous statistical methods - without disclosing a sometimes
much larger set of similar exploratory efforts which yielded no supportable
findings. His point is that valid statistical science requires the construction
of pre-defined protocols for EDA as well as for definitive statistical
testing. The overall protocol (or set of protocols) should be reported
clearly, transparently in the publication(s) resulting from the research.
How much of this belongs in the Ethical Guidelines? Certainly, we cannot
present all of the considerations above in such a document. Can we cover
all of the most essential elements in just a few well-chosen placements
of just a few words each? Here are some candidate changes:
II. ETHICAL GUIDELINES
A. Professionalism
1. Strive for practical significance, not just statistical significance. Typically, combine normative understanding of the subject matter issues, statistical protocols that are clearly defined before looking at the data, and power analyses or similar justification of both the practical significance of the study and the sample sizes needed for valid results.
2. Considering possible researcher/data provider bias as well as
random variation, use data selection processes that will be consistent
with clear, transparent treatment of the issues during the research and
with accurate understanding of that treatment by readers of the resulting
publication(s).
3. Use only statistical methodologies suitable to the data and to
valid results.
<skipping ahead to II.D.>
Carolin M. Frey also noted that II.D.6. (protecting special populations)
is really a component of II.D.1. (protecting human research subjects generally.)
She, along with Mary Grace Kovar suggested including references. As a result,
II.D.1. has been rewritten to combine the human subjects protection items,
address power analysis, and add federal references. The former II.D.6 has
been eliminated.
D. Responsibilities to Research Subjects
1. Know and adhere to appropriate guidelines for human subjects protection,
including protection of special populations who may not be fully able to
protect their own interests. Assure that normative understanding of the
subject matter combines with power analysis or similar justification to
support both the practical value of research on human subjects and the
sample sizes to be used. [U. S. federal guidelines are administered by
the Office for Protection from Research Risks (OPRR) at the National Institutes
of Health (NIH.) The regulations are defined in Title 45 of the Code of
Federal Regulations, Chapter 46 (45CFR46). State and local rules, private
organization guidelines, and regulations or guidelines in other countries
may differ.]
2. Avoid excessive risk to research subjects and excessive imposition
on their time and privacy.
<skipping to II.D.7.>
7. Know and adhere to appropriate animal welfare guidelines in research
involving animals. Assure that normative understanding of the subject matter
combines with power analysis or similar justification to support the practical
value of the research and the sample sizes to be used.
Responsibilities of Those Employing Statistical Practitioners; Responsibilities
of "Senior" Statisticians
James F. Ward, Ph.D., Solvay Pharmaceuticals, noted that moral behavior
has been defined as the result of a moral agent operating in a moral environment.
The July 31 and earlier drafts of the Guidelines address only the responsibilities
of the individual, the moral agent. If the Guidelines fail to address the
issue of a moral environment for the statistical practitioner to work in,
then an essential component will have been left out.
Others in the audience also noted that senior statisticians have a responsibility
to support more junior statisticians in resisting inappropriate pressures
of expediency or lack of ethics. That led to a discussion of whether "senior"
in this sense referred to age, position, prestige, or to some other indicator
of the power to intervene between more subordinate practitioners and those
who would impair their moral environment.
The audience and the Panel agreed this issue was sufficiently important
to require some mention in the Purpose statement, I.A., as well as a separately
defined section of Part II.
<skipping to new section II.H.>
H. Responsibilities of Organizations or Individuals Employing Statistical
Practitioners, such as Employers, Attorneys, or other Clients.
1. Recognize that statistics is based in objective science. Results
of valid statistical studies may turn out to be contrary to the expectations
or desires of those commissioning the study or to those of the statistical
practitioner.
2. Valid results can only result from competent work in a moral environment.
Pressure on a statistical practitioner to deviate from the Guidelines above
is likely to damage both the validity of study results and the professional
credibility of the practitioner.
3. Statistical practitioners have ethical obligations to keep methodology
in the public domain; proprietary reservation of statistical methodology,
if justified at all, should be as limited as possible in time and scope.
4. Statistical practitioners and others have a social responsibility
to support sound statistical analysis and to expose incompetent or corrupt
statistical practice. In cases of conflict, practitioners and those employing
them are encouraged to resolve issues of ethical practice privately if
possible. If private resolution is not possible, recognize that statistical
practitioners have an ethical obligation to expose incompetent or corrupt
practice before it can cause avoidable harm to research subjects or to
society at large.
5. Within organizations and within professions using statistical
methods generally, statistical practitioners who have greater prestige,
power, or status have a responsibility to protect the professional freedom
and responsibility of more subordinate statistical practitioners to comply
with these Guidelines.
To foreshadow this new section on responsibilities of those employing
statisticians, the following is to be added as the last sentence of the
Preamble, I.A.:
"Employers, attorneys, and other clients of statistical practitioners
have a responsibility to provide a moral environment which fosters use
of the ethical guidelines."
Informed Consent
Michael O'Fallon, Ph.D., Mayo Clinic, noted that statistical practitioners
cannot personally accept the responsibility in II.D.4. to "obtain" informed
consent of human research subjects. Other people typically perform that
function. They can be attentive to assure that obtaining informed consent
is included in the study protocols of research studies involving humans.
Carolin M. Frey also suggests:
"Prior to accepting data for analysis or manuscripts for review, ensure
that appropriate subject approvals were obtained."
To combine these ideas, the revised II.D.4. no longer states "Obtain
informed consent . . ."
4. When participating in a study involving human beings, analyzing
data from such a study, or reviewing manuscripts which report on such studies,
consider the conditions under which the human research subjects assented
to provide data, including any informed consent statements and assurances
of privacy and confidentiality. Respect those conditions as if they constituted
a contract between each of the research subjects and yourself.
"Acknowledgment"
He also noted that there is a problem with "acknowledgments" of statisticians.
Various people have disagreed as to the degree of responsibility a statistician
or scientist should assume for the competency and ethics of a study under
various circumstances. In general, co-authorship implies personal responsibility
for the parts of the study performed by or supervised by that individual
as well as general agreement with the overall report of the study methods
and results. Acknowledgment of a statistical practitioner means, at a minimum,
that the statistical practitioner did some professional work related to
the study. That professional work may or may not have been actually used
in the study. It may or may not have had an impact on the way the report
was worded or presented. It may or may not imply that the statistical practitioner
actually understood what other work was done or had formed an opinion as
to the validity of the conclusions. It may or may not imply that the statistical
practitioner had been aware of the contents of the report before publication.
Because "acknowledgments" are rife with potential confusion, the Mayo
Clinic has adopted a policy of prohibiting any acknowledgment of their
statisticians. Others in the audience noted that acknowledgments may be
innocent and appropriate, especially when the statistical practitioner
has aided the study at a level below that which is appropriate for co-authorship.
This suggests an entry in II.A. - Professionalism:
4. Do not join a research project unless you can expect to achieve
valid results and unless you feel assured that your name will not be in
any way associated with the project or resulting publications without your
explicit consent.
(Subsequent items renumbered.)
It can be further addressed by entries in II.E. - Responsibilities to
Research Team Colleagues and II.H. Responsibilities of {those employing
statisticians}:
E. Responsibilities to Research Team Colleagues
1. Inform colleagues about relevant aspects of statistical ethics,
including your right of refusal of authorship or acknowledgment.
H. Responsibilities of Organizations or Individuals Employing Statistical
Practitioners, such as Employers, Attorneys, or other Clients.
6. Allow statistical practitioners to refuse authorship or even any
acknowledgment regarding projects or publications with which they disagree
professionally.
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REVISED DRAFT for General Comment - August 27, 1998