Yes, I think Rychetnik et al., have a point. The simple evidence-based
question of whether a technology works on a selected set of patients may
not be sufficient for policy decisions in public health. This is partly
a medical question of generalizability, when a broader spectrum of
patients must be considered. But also, nonmedical issues of compliance,
accessability, and implementation can detract from effectiveness. Then
there are the cost-benefit questions. Finally there are cultural and
political issues that are increasingly coming into play as biotechnology
develops controversial abilities. Many of these public health issues
could be addressed in an evidence-based fashion, but whether they are or
not is another matter. Also, I believe the authors are questioning
whether all of these questions can or will be answered with the EBM gold
standard of large RCTs; in which case, ample description and access to
patient level data becomes crucial for other methods, such as
retrospective multiple regression analysis.
David L. Doggett, Ph.D.
Senior Medical Research Analyst
Health Technology Assessment and Information Services
ECRI, a non-profit health services research organization
5200 Butler Pike
Plymouth Meeting, Pennsylvania 19462, U.S.A.
Phone: (610) 825-6000 x5509
FAX: (610) 834-1275
http://www.ecri.org
e-mail: [log in to unmask]
-----Original Message-----
From: Sontheimer, Daniel MD [mailto:[log in to unmask]]
Sent: Thursday, January 31, 2002 9:25 AM
To: [log in to unmask]
Subject: Public Health
Here's one to mull over with your morning cup of coffee:
Criteria for evaluating evidence on public health interventions
J Epidemiol Community Health 2002;56 119-127
http://jech.bmjjournals.com/cgi/content/abstract/56/2/119
L Rychetnik,Effective Healthcare Australia, School of Population Health
and
Health Services Research, University of Sydney, Australia
P Hawe and A Shiell, Department of Community Health Sciences, University
of
Calgary, Canada and School of Public Health, LaTrobe University,
Australia
"......Public health interventions tend to be complex, programmatic, and
context dependent. The evidence for their effectiveness just be
sufficiently
comprehensive to encompass that complexity. This paper asks whether and
to
what extent evaluative research on public health interventions can be
adequately appraised by applying well established criteria for judging
the
quality of evidence in clinical practice. It is adduced that these
criteria
are useful in evaluating some aspects of evidence. However, there are
other
important aspects of evidence on public health interventions that are
not
covered by the established criteria.
The evaluation of evidence must distinguish between the fidelity of the
evaluation process in detecting the success or failure of an
intervention,
and the success or failure of the intervention itself. Moreover, if an
intervention is unsuccessful, the evidence should help to determine
whether
the intervention was inherently faulty (that is, failure of intervention
concept or theory), or just badly delivered (failure of implementation).
Furthermore, proper interpretation of the evidence depends upon the
availability of descriptive information on the intervention and its
context,
so that the transferability of the evidence can be determined. Study
design
alone is an inadequate marker of evidence quality in public health
intervention evaluation......."
Dan Sontheimer, MD
Associate Director Spartanburg Family Medicine Residency
Spartanburg, SC
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