4. Stuff Ups 2June 14, 2013
All medical tests are subject to a % error.
This is a FALSE POSITIVE.
This may not be a problem if you are advised to, say, take more Vitamin D to correct the problem you don’t have. But if you are being advised to undergo major surgery, a second test is advisable.
As statistician Michael Blastland explained in Everyday risks: when statistics can’t predict the future (The Guardian 9 JUN 2013):
False positives are common for the simple reason that if you test a million healthy people, even with a 99% accurate test, you will still have 10,000 wrong results. And that’s not including human error. Hopefully, you will not experience one of these: