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

Re: Evidence-based medicine is not THAT funny

24 November 2005

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 )

Competing interests: None declared

Larry M. Weisenthal, Medical Director/Laboratory Director

Weisenthal Cancer Group 16512 Burke Lane Huntington Beach, CA, USA 92647

Click to like: