I remember my doc told me OSCAR accuracy is 92%, while Panaroma and Harmony test accuracy is 99%. I chose the Panaroma test in a heartbeat.
Misleading statistics. Accuracy 7% difference doesn't seem large right? But this is the wrong stat to look at. Let me explain.
Accuracy is basically how often the test is gets the answer right. But a test can have a high accuracy rate and still have sky high false positive rate. Let me show you.
Imagine if a disease is super rare, say 1 in 100,000.
You can have a test that when done on 100,000 cases it says
A) "ok", 92,000 times and its right 91,999 times, wrong once
B) "not okay" , 8000 times and it's right 1 time, and wrong 7,999 times.
Accuracy is (91, 999+1)/100,000 =92%. Aka out of the 100,000 who test, and 92% get the right result. Sounds good!
However notice if you are told by the test you are "not okay" (you are one of the 8,000) how scared should you be? Believe it or or not in this scenario you should still be extremely optimistic as you are still extremely unlikely to have the disease
Why? Because of the 8,000 times the test says "not okay", but it is right only once.
That's a false positive and rate of 7999/8000! Or chances you really have the disease to is still only 1 out of 8,000. Still very good odds.
Essentially for conditions that are extremely rare like genetic disorders, a test is can be very "accurate" and still have very poor false positive effects rate because it is so rare to occur.
This is basically what is happening here with the Oscar test
Things like Harmony etc are not only accurate they have high sensitivity and high specificity rates or low false negative and low false positive
Eg
https://www.nipt.se/performance/ states the harmony test has a sensitivity and specificity of 99.5% to 99.9%, means the false positive of rare is 0.5 to 0.1%
Hope this helps.
