Monday, April 13, 2009
Not all tests are worth taking
From the RoundTable blog
I once had a patient who wanted an AIDS test but refused to have his blood drawn. After hemming and hawing for the better part of the visit he revealed his conundrum: He was afraid of catching the AIDS virus from the collection needle.
How strange, I thought, that a person could fear disease from the test to uncover it.
In an oblique way, he had a lesson to teach. I'm not saying a blood test will ever give you AIDS or any other disease, but there are plenty of respectable tests offered by well-meaning people that put you at greater risk of harm than good.
Arnold Palmer himself used to appear on national TV extolling the virtues of the PSA test for prostate cancer. He'd just been diagnosed with prostate cancer and wanted to make sure all men knew about the test.
As a golfer and generally terrific guy, Palmer wins my utmost respect. As a scientist, not so much. The PSA test has never met criteria as a valid screening test. Nevertheless, men have been groomed to seek it on the same terms that women seek mammograms.
It's important to know the difference between a screening test and a diagnostic test. A screening test seeks out disease before a problem occurs. A diagnostic test looks for the cause of a problem that has already appeared.
So, if you have a lump in your breast, trouble emptying your bladder or pain in your chest, your doctor might want to order a mammogram, a PSA or an ECG. But what if you have no symptoms?
Might as well order a bunch of tests, just to make sure everything is OK, right? A simple test can't hurt. Can it?
Yes, it can, and does -- all the time.
Say you feel fine, but your routine PSA is a little high. That leads to a rectal exam and, often, a course of antibiotics. Then you get a second blood test (and rectal), then a referral to the urologist, who performs a third blood test (and rectal), then a (rectal) ultrasound, a (rectal) prostate biopsy, then surgery to remove or destroy the prostate, possibly complicated by incontinence and impotence (with a lifetime of adult diapers and impotence treatments), radiation treatments and a few more PSA tests and doctor visits (with rectal) per year for the rest of your life. That first PSA just racked up some serious pain, humiliation and medical costs.
"Fine," you say, "but the cancer got treated. That's got to be worth something."
For some types of cancer, yes. Colonoscopy, for instance, has lowered the rates of colon cancer and death. Even though it costs far more than a PSA blood test, screening colonoscopy is a much better deal. To learn which other health tests and habits are proven worthwhile, go to www.ahrq.gov/consumer/ and scroll to "Prevention and Wellness." You'll find a surprisingly short list.
It does not include PSA. In its crusade for legitimacy, the PSA has led to a monstrous expenditure of resources and has taken a massive emotional and physical toll on millions of men, but has failed to prolong lives. A recent large study confirms that U.S. men who are diagnosed with prostate cancer by PSA die at the same age as, or perhaps even younger than, those not offered the test.
How did the PSA achieve such widespread acceptance? Look for the answer at the intersection of the free market and big medicine. Most anyone who deals with prostate issues -- diagnostics to doctors to drugs to diapers -- has made a bundle on the coattails of the PSA.
If we got duped by the PSA, what else should we watch for?
You see it once or twice a year, parked at such venerable institutions as your church, community center or nursing home. The Bus boasts fancy tests "that your doctor isn't allowed to order," and backs them up with testimonials rather than facts. For just a couple hundred dollars you can have the peace of mind of modern ultrasound technology.
Steer clear of The Bus. It's full of screening test rejects that fall short of even the lowly PSA. The few worthwhile tests can be ordered more reliably by your doctor through simple blood work or referral. Otherwise, your $200 investment in peace-of-mind could well become a $20,000 odyssey into the world of the medical unknown.
Words of wisdom: Watch what you look for -- you might just find it.
Huff, who lives in Patrick County and practices family medicine, is a columnist for The Roanoke Times.