Hacker News new | ask | show | jobs
by adjkant 1628 days ago
While the author may not be well versed or focusing on the stats side, you're missing the human side here I think.

> the tests are inaccurate, when in reality the tests are accurate

If the test make someone consider terminating a pregnancy or even considering it, that's a lot of pain. So for that human, the test is failing its purpose potentially, depending on the value calculation of terminating a viable pregnancy vs the severity of the issue if it comes to term.

For a human, accuracy as you defined it means little to nothing. Usefulness and helpfulness are far better metrics, and such a high false positive rate is clearly causing issues in respect to those, which is what the article is highlighting.

2 comments

Usefulness and helpfulness are far better metrics, and such a high false positive rate is clearly causing issues in respect to those

How exactly do you plan on codifying usefulness and helpfulness?

A high false positive rate is not necessarily a bad thing and may instead be the catalyst for additional tests to confirm the first one. The tests accuracy may actually be 100%, which is great because it avoids a child being born with a fatal genetic disease. Would you prefer a high false negative rate that misses these diseases instead?

Or maybe you’re missing the human side of having a child born with a serious genetic defect?
Is it better to terminate 85 pregnancies which do not have a serious defect in order to catch 15 which do? At what point is it not better to terminate 100% of pregnancies?
> Is it better to terminate 85 pregnancies which do not have a serious defect in order to catch 15 which do?

Yes, it’s absolutely better to do that. Of course, the actual ratio is much better than that because we do follow-up tests after the screen.

Your first question and answer is against medical ethics. If you’re a physician you know that terminating pregnancies based on a non-specific but sensitive screening test is inappropriate (do no harm).

However, you are correct in your second statement - there are much more specific follow up tests which improve diagnostic accuracy.

Medical utilitarianism should never be so cruel and gruesome as to eliminate 85 healthy and wanted pregnancies in order to find and eliminate 15 genetic aberrations.

> At what point is it not better to terminate 100% of pregnancies?

Everyone should decide for themselves. Having seen the long term consequences I would rather err on the side of caution, even if it were difficult to become pregnant.

Such diseases are often incurable and significantly degrade the quality of life of not only the person to be born but the whole immediate family. At least in the US the there isn't enough social safety net or support too offset the crushing costs.