Tuesday, June 13, 2006

Too Much Information -- DNA Home Kits

Imagine being able to order a genetic test over the Internet -- to see if you have inherited a predisposition to cancer or whether there might be a genetic component to your infertility -- without having to get approval from your doctor, consult a genetic counselor or risk the fallout that might result from filing an insurance claim.

Now imagine sitting alone at your home computer and receiving devastating news: test results that will forever change your life -- and your family's -- in ways you never anticipated.
Those are the promises and perils of the nascent, growing and largely unregulated phenomenon of direct-to-consumer (DTC) genetic tests. For the price of a mail order test kit containing swabs to scrape cells inside the cheek, nearly a dozen companies now offer curious consumers the chance, without ever seeing a doctor, to learn whether they carry genes for cancer, blood disorders or other diseases. Some companies are marketing personalized diet or skin care recommendations based on DNA analysis using tests that are not widely accepted in the scientific community.

For more, read on...

1 comment:

Kevin T. Keith said...

This is a serious matter, but I am always torn in trying to understand how to respond to it.

One problem the article does not mention is third-party testing - the growing phenomenon of ordering DNA tests on other persons (almost always parents testing their children, usually in a paternity or custody dispute) for the benefit of the person seeking the information. Children have an interest in their own genetic information and its confidentiality; when parents want testing for their own purposes, the children often cannot refuse to participate, but such testing would never meet the "best interest" standard for medical procedures on children in other settings. Some commercial labs offer to test samples other than mouth swabs - which at least require the cooperation of the subject - encouraging people to submit swabs from drinking glasses, or samples of toothbrush bristles or hair from hair brushes. This allows testing not only against the will, but without even the knowledge, of the subject. And, finally, even when testing does not itself violate anyone's privacy, it often happens that the results of genetic tests on one individual have clear implications for the genetype of a related individual. Healthcare professionals try to preserve confidentiality in such cases, but private individuals may not think to do so, or act with the same restraint. For all these reasons, I think there is a distinct need for legal protection against invasions of privacy resulting from unregulated private testing.

Regarding the issue raised in the article, however - private testing without evidence of clear medical need, and with questionable ability to put the results in context and provide support for the patient afterward - I think things are not so clearcut.

The article is surely right that there are real dangers in these practices: of patients misinterpreting or over-reacting to test results (either positive or negative); of patients failing to seek professional assistance with the problems they do have; with patients trying to act on information revealed by the tests but not knowing what is appropriate or what further steps are even possible. To the extent that any of these things occur, they bring real harms.

And, there is another aspect of this testing that the article does not mention, but is a real worry. Testing is almost always ordered by healthcare professionals in recognition of perceivable patient risk. Patients are tested only when there is some reason to think they may have a condition that the test will confirm. But making testing available to just anyone who asks for it - prompted by curiosity, something they may have heard, their own interpretation of something from their medical history, or perhaps the feeling that simply performing as many tests as possible is a kind of insurance policy - is essentially equivalent to a mass screening program for whatever conditions the tests are aimed at. Most of the people who order the tests will not truly be at risk for the condition, unlike in the clinical setting, where the percentage of people tested who actually have the condition is fairly high, because they are selectively chosen to take the tests. The results of mass screening programs, even with tests with high specificity (true positive rate), is inevitably a large number of false positives. This is not because the tests are bad, but because the true-negative population is so large, and thus produces many false positives even though the false-positive rate (as a percentage of that large population) may be low. For this reason, mass screenings of any population not at risk for a given condition is generally discouraged - but the rise of commercial testing, and the financial incentive these companies have to test as many people as possible, runs directly counter to this wisdom, and will unquestionably result in many people being informed they have a given condition when they do not, and those people then lacking the support or resources to work out the truth for themselves.

So, there are clearly good reasons to fear the results of unbridled private genetic testing outside a context of clinical treatment, education, and support. Even so, I think there is an important flip side to the issue.

That side, obviously, is the matter of personal liberty, or patient autonomy. Whether or not they go about it the way we would prefer them to do, people have an obvious interest in knowing about their health status. Beyond that, they have a simple desire to know - for both practical and perhaps whimsical reasons. (Note the popularity of highly dubious "racial ancestry" genetic testing - a result that not only has very limited practical use but is almost meaningless just on scientific grounds. Nonetheless, people seem to find it fascinating.) People also have the right of control of their own bodies, which I would think includes the right to hire somebody to take a look at (part of) your body and tell you what they think of it. Blocking the exercise of any of these interests or impulses is a significant encroachment on autonomy. And the argument that patients will harm themselves by making ignorant or ill-considered decisions is surely, by now, fully discredited as a defense of paternalism against autonomy.

We ought to put this in broader perspective as well. In the end, people constantly make highly significant choices for themselves, often on the basis of flimsy or poorly-understood information. They get married, choose careers, change jobs, change homes, engage in risky sports, eat unhealthy foods, and undertake a myriad of other daily acts and decisions that put their interests at risk, and which in many cases are not optimally rational or healthy. We recognize their freedom to do so. We would never imagine insisting that they had to make an appointment, consult a professional (at a considerable fee), and get counseling in order to do any of these things - many of which are likely to have much more influence over the course of their lives than simply getting the results of a genetic test.

It appears to me that the insistence on clinical review and counseling for genetic tests smacks strongly of professional hegemony, or more exactly of professionals' conveniently taking advantage of the fact that these tests have not until now been available outside the clinical setting in order to take steps to keep it that way. And we can agree that these professionals are motivated by concern for the patients' optimal physical health - but we know too well that such concerns often run counter to respect for patients' optimal exercise of their own liberty, autonomy, and values.

If these tests become more widely used, the false-positive problem will become acute, and the incidence of patients making bad decisions on incompletely-understood information will rise. But in both cases these consequences will be the result of patients freely making their own choices about what they want to know and what they want to do about it. Some of those choices will be bad ones - just as some choices of marriage partner, job, home, friends, investments, or other risks are bad ones. But each such choice is a free choice as long as we allow it to be. And I am inclined to do so.