>>14114263I realize someone probably already answered this but:
20% chance.
Presumably the people tested were a random enough trial that they'd conform to the population average of Hepatitis C cases.
Since (probably) only 10% of people tested had it - the 90% of cases that had it and tested positively for it are multiplied by 0.1
Applying this logic to the rest of the chart you have the following results:
+ | + = 9%
+ | - = 1%
- | + = 36%
- | - = 54%
Then you filter for only positive test results:
+ | + = 20%
- | + = 80%
Can doctors do anything to increase this certainty?
They could test people 3 times. This would put the odds of a misdiagnosis at "just" 51.2%.
