[labaraka]

> For instance, if the BRCA-related risk assessment for breast or ovarian cancer reports a false positive, it could lead a patient to undergo prophylactic surgery, chemoprevention, intensive screening, or other morbidity-inducing actions, while a false negative could result in a failure to recognize an actual risk that may exist.

I cannot imagine someone getting surgery or chemo solely based on a 23andme heads up warning and without consultation with a specialist physician.

As someone working in medical devices, this dramatic language is extremely frustrating.

[alanctgardner2]

That example is a bit severe, but I think the Warfarin compliance example is spot-on. You receive a prescription for a drug, but your magic internet test tells you to take a lower dose, because you're "sensitive". Then you die of an aneurysm because the test was wrong.

People are completely stupid when it comes to medical issues. I heard a woman complaining that she couldn't eat honey because she was allergic to fructose. I work with at least 3 "gluten-sensitive" people (it's pretty unlikely they all have Celiac disease, it's not a big office), because it's a hip thing to do. Hell, didn't Angelina Jolie have a prophylactic double mastectomy?

edit: Since everyone is jumping on the Angelina Jolie example. I don't think her decision was made based on a single spit test. And I think she had doctors advising her. But the amount of publicity it got makes me worry that it could become needlessly popular based on self-diagnosis (like not eating gluten).

[RobAtticus]

>Hell, didn't Angelina Jolie have a prophylactic double mastectomy?

The placement of this in your post seems to imply you think she was being stupid with her decision, or thought it was in some way "hip" to do. She has a family history of breast and ovarian cancer and has a defective gene that made her chances of getting breast cancer 87%. As she's pretty wealthy, I'm going to guess that she has pretty good doctors and didn't make the decision on a whim. Also since it was major surgery I'm going to also assume some doctor saw her at least once before the surgery and s/he didn't just take her word for it that the surgery was in her best interest.

Yes there are plenty of people who don't have a clue when it comes to medical issues, but I'm not sure why you felt the need to lump Jolie in with your other examples.

[alanctgardner2]

I don't think she did it to be hip - I'm sure she had many doctors advising her, and she underwent many tests before making her decision. But it was heavily publicised, and it set a dangerous precedent that people with less access to medical resources will send away this $100 test, see "cancer risk", and start pushing for unnecessary surgery.

[RobAtticus]

I mean, it is major surgery. There is a pretty big difference from somebody cutting out gluten from their diet and somebody getting surgery. If I decide one day I'm allergic to gluten, I can stop eating it without consulting a doctor. Similarly, as the sibling comment mentions, if McCarthy thinks vaccines cause autism she can stop getting them for her and her children without consulting a doctor. Sure, maybe some women will start pushing for unnecessary surgery, but they will also have to find a doctor who is willing to accommodate them and perform the surgery in the absence of evidence (or perform it based on a website).

It just doesn't jive with me that they are remotely the same thing. I think Jolie is a particularly poor example here and serves as a distraction for an otherwise decent point.

[tedunangst]

As a minor counterexample, Jenny McCarthy is also pretty wealthy and has access to good doctors, should she want to talk to them.

[DanBC]

> Hell, didn't Angelina Jolie have a prophylactic double mastectomy?

I really hope she had more information than a 23andme result.

As I understand it she has a strong family history, and the mutated gene. Prophylactic surgery can reduce risk in those cases.

Most people don't understand what "risk reduction means" so I hope she had doctors who were able to explain it to her.

This website http://www.cancer.gov/cancertopics/factsheet/Therapy/risk-re... describes it as a 95% reduction in risk.

Very very few people are going to understand what that means for them. Gerd Gigerenzer has a book that's a useful discussion of why presenting risks as percentages is bad.

http://www.amazon.com/Reckoning-Risk-Learning-Live-Uncertain...

And here's an example from the book http://imgur.com/zO4zkl4

[logfromblammo]

Just because people don't have an M.D. doesn't make them automatically wrong. The patients that complain about gluten have access to information you do not have. Namely, they are able to experiment with their own diet. When they eat gluten, they feel bad. When they stop, they feel better. Who cares if it's placebo effect? If they feel better not eating gluten, tell them to stop eating gluten and support them in their decision instead of writing them off as part of a dietary fad.

And I certainly hope you have at least done some research on fructose metabolism before writing that woman off as a kook. Even if it is all in her head, you can make her at least happier, if not healthier by suggesting that she also avoid foods with sucrose or monomeric fructose, and substitute them with alternatives such as xylitol, glycerol, maltose, or ordinary glucose corn syrup.

If the patient is ignorant, that is a condition the doctor should be expected to cure. If the patient is stupid, they should find a less arrogant personal physician.

[tedunangst]

Diagnosing the true cause of someone's "gluten allergy" would allow them to start eating gluten again. Since gluten is pretty much everywhere, I'd say that'd be a nice quality of life improvement.

[logfromblammo]

Or the diagnosis might confirm the patient's suspicions, and they might have to monitor their gluten intake for the rest of their life. Either way, there should be actual evidence available before a definite conclusion is reached.

Low-cost screenings, such as 23&Me mail-in swab tests, elimination diets, or common blood and urine tests are a great way to start building up that objective evidence without first doing harm to your patient's wallet.

[alanctgardner2]

The FDA just wants to make sure that 23&Me's tests are accurate, which could actually lead doctors to trust them more rather than replicating them at the patient's expense.

[iloveyouocean]

RE: Warfarin.

When you receive a Warfarin prescription, you begin very close monitoring that involves daily then weekly then monthly blood tests (for the rest of your life) to determine your dose and monitor the effect of the drug in your body. Someone choosing to take a lower dose because of 23andme results would be blatantly and intentionally disregarding the results of testing and the advice of their Drs. The 23andme result that you may be sensitive to Warfarin is something to mention at the outset of your treatment, and nothing more. Also, taking a lower than therapeutic dose of Warfarin would not cause an aneurysm, but would be more likely to cause a clot.

1) I dont see how 23andme results for Warfarin would in practice negatively effect a patients drug regime. 2) You seem to know very little about Warfarin and should take that into consideration when commenting on issues surrounding it.

[berberous]

Why is Jolie's decision stupid? If she had BRCA mutations she could have had over 50% lifetime risk of breast cancer. Seems like a reasonable step to take.