Health-Care Tradeoffs

November 22, 2009

Readers, at least those in the US, have undoubtedly heard by this time that a new report by the US Preventive Services Task Force recommends that the use of routine mammograms be reduced from annual to every other year for women over 50, and be eliminated for women between 40 and 50.  I have been bemused and somewhat perturbed by some of the reaction to this recommendation (which, by the way, is just that).

Let me first say that I have not examined all of the evidence, so I am in no position to evaluate the Task Force’s recommendation.  Even if I had seen it all, I may not be qualified to fairly judge some of it.  I am not at all surprised, or bothered, that there may be some controversy or disagreement over the interpretation of some parts of the evidence.  Making a recommendation such as this one involves reviewing a mass of statistical and other evidence, and trying to make an intelligent trade-off between the advantages and disadvantages of more (or less) testing.  This inevitably involves a certain amount of professional judgment, and exactly where the trade-off should be made is a matter about which reasonable people can disagree.

That sort of disagreement does not bother me.  What does bother me is the reaction that seems to assume that no trade-off needs to be made: something along the lines of, “If even one additional cancer is detected, it is worth whatever it costs.”  The first observation that must be made is that the costs, certainly in this instance, are not just financial.  Excessive exposure to ionizing radiation (like X-rays) can cause cancer.  Follow-up biopsies have their own risks, including infections.  The Task Force’s report cited the unnecessary distress that may result from a false positive test result.  Also, of course, there are bound to be some false positive diagnoses that result in unnecessary surgery.  And the economic costs are real enough.  No one likes to think about putting a monetary value on health, but we do have to do it, all the time.

Pretending that a trade-off is not required is just a retreat to magical thinking: somehow, we can have it all if we only close our eyes and wish with all our might.  Unfortunately, when we open our eyes, we still have to grow up.

New Internet Explorer Vulnerability

November 22, 2009

A new exploit affecting Microsoft’s Internet Explorer has been published, as reported by the SANS Institute and Network World.   The flaw is, apparently, due to an invalid pointer in the HTML viewer library, mshtml.dll, and affects Internet Explorer versions 6 and 7; version 8, the current version, is apparently not affected, but the older versions are still in widespread use.  The currently published exploit is not entirely reliable, according to security vendor Symantec; but the likelihood of a better exploit appearing is high, because flaws of this type are coveted by the Bad Guys, since they allow software to be installed on the victim’s machine if he merely visits a compromised or malicious Web site.

There is no information from Microsoft at the moment on a potential fix.  The exploit does require that JavaScript be enabled in order work, so disabling JavaScript should mitigate the threat.

Update Monday, November 23, 11:52

Brian Krebs at the Washington Post has posted a note about this on his “Security Fix” blog.

To repeat something I’ve said before: Internet Explorer, especially in its older versions (6 and 7), is a security nightmare.  You really should consider switching to Firefox or Opera; at the very least, upgrade to Internet Explorer version 8.

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