Testing prevents nothing.
One doesn’t take a test in school to prevent stupidity. They take it to show if they know the material or not, and to let the teacher know what areas that student needs to focus on. Likewise, a medical test isn’t meant to cure a disease, rather it’s to tell doctors whether one has a certain issue or disease. That information helps doctors know what steps (if any) need to be taken next.
Testing won’t make a disease “go away”. Just like not taking a pregnancy test won’t make one any more or less pregnant. Testing simply gives one more knowledge to help them make more informed decisions.
Testing (in and of itself) prevents nothing. That’s not its purpose. Its purpose is simply to identify what needs or doesn’t need to be done.
A cancer test can only show if the patient has or doesn’t have cancer. It can’t treat or prevent it. It merely shows the doctor if the patient has or doesn’t have cancer (or how an already diagnosed cancer is progressing).
Likewise, a test at school isn’t meant to teach a student, it’s meant to identify what the student does or doesn’t know.
Does that make more sense?
Shuhak 