Chance News 13

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Do not put your faith in what statistics say until you have carefully considered what they do not say.

William W. Watt


Here is a Forsooth from the January 2006 issue of RSS News with a comment by the editor.

Alcohol is now 49% more affordable than it was in 1978

Sky News
20 November 2005

[readers are invited to send in their
suggestions as to the exact definitions
of a and b in the equation b = 1.49a]

Do Superfluous Medical Studies Exist?

In Chance News 12 can be found an item Superfluous Medical Studies, It references David Brown's article in the Washington Post of January 2, 2006 in which he "looks at several instances where...the evidence is so convincing that no more studies need or should be done." His phrase is "What part of 'yes' don't doctors understand." In particular, "he cites the use of aprotinin in heart surgery" which since 1987 had 64 studies each conclusively showing that aprotinin reduced bleeding. Researchers were criticized for persisting in evaluating aprotinin without being fully aware of the previous research.

Less than four weeks later on January 26, 2006, the New York Times and the Wall Street Journal had respective headlines, Doctors Urge Ending Use of Heart Surgery Drug and "Serious Risks Are Found In Heart Drug." The heart drug, Trasylol, is, as you might guess, aprotinin! Some 4374 patients were in the study published by the New England Journal of Medicine--"1295 were given aprotinin and 1705 one of two other drugs, both generics [of older drugs]" There was also "A control group, 1374 patients" who "had no drugs to prevent bleeding."

According to the Wall Street Journal, "About 29% of the Trasylol patients suffered a stroke or heart-related complication, compared with about 21% of the patients taking the generic drugs and 19% getting no drugs." The breakdown comparison between Trasylol and the alternatives is as follows:

"5% of patients on Trasylol required kidney dialysis vs. 1% of those on one of the two alternative drugs."

"16% of Trasylol patients had a myocardial infarction (heart attack) vs. 12% and 13% of those on alternatives."

"9% of Trasylol patients experienced heart failure vs. 6% and 5% on alternatives."

Furthermore, "The researchers also found that cheaper alternatives ("$10 to $50" per patient) to Trasylol ($1000 per patient) were just as effective in limiting blood loss." The New York Times wrote, "The [New England Journal of Medicine] article said that halting aprotinin use globally would prevent 10,000 to 11,000 cases of kidney failure a year and save more than $1 billion a year in dialysis costs as well as nearly $250 million spent on the drug itself." In addition, "The study is significant because it was conducted without drug-industry funding at 69 medical centers, including many of the top U.S. hospitals."

Naturally, Bayer, the manufacturer of Trasylol, a drug which "in the first nine months [of 2005]" had a "world-wide sales of just less than $200 million" and is used in 150,000 patients in the U.S., "believes that Trasylol is a safe and effective treatment." Though the study was large, Bayer points out that it was observational and not a randomized trial. According to the New York Times, the implication is, "Doctors might have assigned sicker patients to a particular drug that could make the results for that drug look bad." However, the Wall Street Journal claims that a randomized trial could not be done because "many hospitals have deemed Trasylol effective and would consider it unethical to allow a patient to get a placebo instead." The study thus resorted to " 'match' like patients across the study groups to control for other risk factors, such as age, gender and additional health problems."

About the only unambiguous conclusion that can be reached is to take good care of your heart so that you avoid the need for by-pass surgery and the associated medication.