saying a test has 85% accuracy tells you nothing about the results of that test. not being hyperbolic - literally nothing. simple proof:

i develop a test for disease X and give it to 1 billion walking around grocery stores in the whole world. it is 85% accurate. results are 200 million people are positive? how many of those people actually have disease X? do you have a guess?

disease X i was testing for was death. every single positive test was wrong. how close was your guess?

you must, at a minimum, know test accuracy _as well as_ disease prevalence to form a statistical guess. death is prevalent in 0% of alive people, so test accuracy is worthless.