4 ms·
This is a key point. If the false positive rate is 18% (as noted in other comments), and the rate of Alzheimer's is 36/100k[1], then for every patient the test
by pge 8y ago
This is a key point. If the false positive rate is 18% (as noted in other comments), and the rate of Alzheimer's is 36/100k[1], then for every patient the test correctly identifies, there are 500 patients that tested positive but did not have Alzheimers. There needs to be significant improvement before such a test becomes useful.
[1] that's mortality rate which I am using as a proxy for incidence rate, though the actual incidence rate is presumably higher (mortality rate from the CDC)
- gooseus 8y agoI'm not good at this (yet), but my understanding is that your prior for just this test would be the likelihood of having Alzheimer's based on the statistical occurrence within the general population. After this test you now have updated priors which may not be good enough to make a certain diagnosis, but wouldn't it still be useful combined with another independent test that has similar rates, since you'd be using these updated priors?
- bsder 8y agoThat depends. I suspect that this test would only be used on those with a family history of Alzheimer's or similar. That alters the Bayesian priors quite a bit. In addition, you can monitor the progress of someone who "tests positive" over time and see if that is really true. Part of the issue with Alzheimer's treatments is that we may be intervening far too late. These kinds of tests may help that.
- iseeyoubydesign 8y agowhat ever , this is not science but gambling with peoples health to declare "look what we can do". They is a very irresponsible approach that amounts more to guess work than any actual discovery. In the end people get old. "Far to late" is because the person already lived a full life.