4 ms·
95% on a 1 in 1000 event means that over 1,000,000 trials 950 true positives ~50,000 false positives False positive breast cancer is pretty bad.
by b_tterc_p 7y ago
95% on a 1 in 1000 event means that over 1,000,000 trials
950 true positives
~50,000 false positives
False positive breast cancer is pretty bad.
- magwa101 7y agoCost of false positive is retest and observe, this seems like a very low cost. Also, stop consuming sugar.
- timthorn 7y agoWhat about the anxiety and distress caused to the patient? How many might undergo an unnecessary mastectomy to be on the safe side?
- colechristensen 7y agoI have a problem with this vision. You can be told the risk factors for everybody, but when you are told the risk factors tailored to you it becomes dangerous? Should we tell everyone they're going to live forever so they live in ignorant bliss while healthy? I can see being unprepared for having that information, but I don't think the solution is not having the information.
- timthorn 7y agoIt's not a risk factor; it's a test outcome. You would be told that you've tested positive with the follow on tests and anxiety that causes. There have been studies into exactly this: https://www.ncbi.nlm.nih.gov/pubmed/22859786 https://www.ncbi.nlm.nih.gov/pubmed/22859786 Specifically on breast cancer screening, the National Institute for Clinical Evidence in the UK has published management guidance that is quite interesting: https://cks.nice.org.uk/breast-screening https://cks.nice.org.uk/breast-screening
- wccrawford 7y agoCan't read that last link outside the UK. They wouldn't be wold they were positive for cancer. They'd be told that the computer predicts that they are at very high risk for breast cancer. That's knowledge that I think people should have, personally.
- SolaceQuantum 7y agoSorry, please explain to me if my interpretation is correct: 1. The cost of a false positive is low. 1a. The cost of a false positive is retesting (what is retesting? Re-mammogramming? Isn't healthcare in USA expensive?) 1b. Observe (so future re-mammogramming and hypervigilance). 2. Additional to the cost of 1a and 1b, cease consuming sugar. Which is a non-insignificant lifestyle change. What I'm saying is... the statements "Rerun expensive tests and maintain hypervigilance seems like a low cost, in addition to major lifestyle changes that affect every level of one's socioeconomic place (eating out with friends/family, cost of food, food availability, habit breaking, possibly culture clashes, etc)." seems pretty much equivalent to absolute nonsense.
- b_tterc_p 7y agoGiven a positive result. P of having the disease are 2%. Given a false result, it’s about 0. Given 2 positive results, assuming independent results (I think that’s unlikely but let’s assume) then the probability of having it is 0.04. I’m not disagreeing that there usefulness to tests, but there is danger too.
- ska 7y agoIf by whatever mechanism your FPR significantly increases biopsy rate, it's not a low cost.
- drderidder 7y agoIt seems they are simply assigning patients to the top risk decile (more accurately than before). Telling someone they are at a high risk is different than a flat-out diagnosis. Better efficacy of the predictive model (fewer false positives and fewer false negatives than before) is a good thing.