I was unfamiliar with the fit test but after checking on it I guess its false positive rate is acceptable because it is used as a screening prior to a more invasive colonoscopy. In other words proper application of the test as a screening tool should result in fewer colonoscopies, not more.
The false positive rate isn’t the problem, the false negative rate is, which is why I mentioned the false negative rate above, and not the false positive rate. Obviously it would result in fewer colonoscopies and that’s the problem. The whole reason people take a FIT test is to avoid getting a colonoscopy. False negatives means a larger percentage of people will have cancer and not be aware of it, and not schedule a more reliable test until the cancer develops further and gets caught later by some other test maybe. The FIT test is better than nothing, but worse than getting a colonoscopy in terms of safety and reliability. It’s popular because it’s convenient, not because it’s highly reliable.
