Hazardous Journeys

Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials

BMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7429.1459 (Published 18 December 2003) Cite this as: BMJ 2003;327:1459

Re: Evidence-based medicine is not THAT funny

I interpret the parachute study as illustrating that, in life or
death situations, one must make judgements based upon preponderance of
available evidence as opposed to proof beyond reasonable doubt. It seems
obvious, but the parachute study makes the point that "evidence-based
medicine" proponents may fail to apply this common sense standard on a
consistent basis.

To cite just one example, the American Society of Clinical Oncology
established a policy recommending against the use of cell culture drug
resistance testing (CCDRT) as an aid to drug selection in cancer
chemotherapy, based on reviews (refs. 1,2) which specifically excluded
from consideration studies reporting the predictive accuracy of CCDRT (of
which there were many), and including only studies relating to the
"efficacy" of CCDRT in improving treatment outcomes (of which there were
virtually none). This was especially curious, as predictive accuracy is
the chief criterion traditionally used to validate all laboratory tests
currently in use in cancer medicine (including hormone receptors,
Her2/neu, gene expression-based assays, and all immunohistochemical
staining tests). Were proof of efficacy (particularly in prospective,
randomized trials) to be the standard for evaluating laboratory tests,
then clinical oncologists should immediately abandon all the laboratory
tests currently used in the management of cancer patients, as no tests
would pass this standard.

Clinical oncology investigators have too often descended into an
exhaustive study of hypotheses which are ultimately of limited importance.
Many cancer treatments are of such limited effectiveness that they do not
deserve to be protected from the competition of other approaches which
are well grounded in peer review science, but which have not yet met the
most demanding standards of "evidence based medicine."

Larry M Weisenthal MD PhD

Huntington Beach, CA


Literature Cited:

1. Schrag D, Garewal HS, Burstein HJ, Samson DJ, Von Hoff DD,
Somerfield MR. American Society of Clinical Oncology technology
assessment: chemotherapy sensitivity and resistance assays. J Clin Oncol
22:3631-8, 2004.

2. Samson DJ, Seidenfeld J, Ziegler K, and Aronson N. Chemotherapy
sensitivity and resistance assays: a systematic review. J Clin Oncol
22:3618-30, 2004

Competing interests:
I direct a private clinical reference laboratory which provides cell culture drug resistance testing as a service to patients and oncologists. (information at http://weisenthal.org )

Competing interests: No competing interests

24 November 2005
Larry M. Weisenthal
Medical Director/Laboratory Director
Weisenthal Cancer Group 16512 Burke Lane Huntington Beach, CA, USA 92647