5 ms·

I'd just like to note that, while we should be conducting many more tests, we should also be aware of the danger of false positives, and the burden that places

I'd just like to note that, while we should be conducting many more tests, we should also be aware of the danger of false positives, and the burden that places on individuals and systems. Some of these tests are just not very accurate, according to an MD I know.

aldoushuxley001 7y ago
Still better to have as one of many screening options
lukifer 7y ago
Always a concern, but under the present circumstances, a false positive (someone quarantines for two weeks who doesn't need it) is far better than a false negative (someone has false confidence in attending public places). Unlike other false positives that could lead to unneeded/harmful interventions (surgery, chemo), erring on the side of false positives would actually be desirable for COVID-19.
- jschwartzi 7y ago
  I’d rather not be quarantined with a bunch of sick people for two weeks if I’m not actually sick. The risk of me getting the virus is much higher there than among the general populace. So I disagree that there are no downsides or risks for a false positive here. Especially as the disease has a chance to kill me.
  - jedberg 7y ago
    You quarantine at home.
    - xnyan 7y ago
      All the restaurants and bars of California and New York are closing or are closed and all the people that work there are hourly wage. How how long do you think they will still have homes? Not trying to be alarmist but I also don’t see how people making an hourly wage are going to continue living in their very expensive states without income.
      - jedberg 7y ago
        Unless the government backstops it, they won't. It is and will be a huge problem. Some states are banning evictions for a few months, so at least there is that option. But it just means they'll be homeless in June instead of April.
      - sp332 7y ago
        Most NYC landlords have agreed to a 90-day hold on all evictions. So... about 90 days I guess.
  - jacurtis 7y ago
    Self-quarantine means they send you home and tell you not to leave for 2 weeks. Unless you are in such an extreme case that you need a respirator or something, in which case they will hospitalize you and you might be around other diseased victims, but if you are in that condition then it is probably not a false positive. There is a shortage of hospital beds worldwide right now, so they are sending everyone home unless hospitalization is considered life-saving.
fma 7y ago
You may have misheard the MD. The current tests have a very low false positive rate. That means if the test says you have Coronavirus, you have it. There's no "burden". Where the tests are "not very accurate" is the false negative. The false negative rate can be as high as 50-60%, depending on tests and how it's administered. Sometimes they will conduct the test twice to improve accuracy. The Roche ones recently approved have a lower negative test rate (10%?) Edit: I removed my mention of 0% false positive rate because nothing in life is absolute.
- whatshisface 7y ago
  A 0% false positive rate is not possible. What if they switch your sample with someone else's while it's being handled by a human? Edit: >That means if the test says you have Coronavirus, you have it. This line implies the parent comment is talking about the false positive rate of the entire testing process that results in you being told you're infected, not PCR as a platonic ideal, theoretical process.
  - irishsultan 7y ago
    That's still not a false positive rate of the test. But I agree that 0% false positive rates are going to be nearly impossible to achieve (for just about anything that isn't mathematics).
    - deleted 7y ago
      [deleted]
  - joking 7y ago
    That’s a protocol fault and has nothing to do with the accuracy of the test
  - fma 7y ago
    From the FDA itself. Note how firm they are in regards to a positive, vs how cautious they are in regards to a negative. If you have COVID-19 RNA in your body...you have the virus. What does it mean if the specimen tests positive for the virus that causes COVID-19? A positive test result for COVID-19 indicates that RNA from SARS-CoV-2 was detected, and the patient is infected with the virus and presumed to be contagious What does it mean if the specimen tests negative for the virus that causes COVID-19? A negative test result for this test means that SARSCoV-2 RNA was not present in the specimen above the limit of detection. However, a negative result does not rule out COVID-19 and should not be used as the sole basis for treatment or patient management decisions. A negative result does not exclude the possibility of COVID-19. https://www.fda.gov/media/135662/download https://www.fda.gov/media/135662/download

aldoushuxley001 7y ago

Still better to have as one of many screening options

lukifer 7y ago

Always a concern, but under the present circumstances, a false positive (someone quarantines for two weeks who doesn't need it) is far better than a false negative (someone has false confidence in attending public places). Unlike other false positives that could lead to unneeded/harmful interventions (surgery, chemo), erring on the side of false positives would actually be desirable for COVID-19.

jschwartzi 7y ago
I’d rather not be quarantined with a bunch of sick people for two weeks if I’m not actually sick. The risk of me getting the virus is much higher there than among the general populace. So I disagree that there are no downsides or risks for a false positive here. Especially as the disease has a chance to kill me.
- jedberg 7y ago
  You quarantine at home.
  - xnyan 7y ago
    All the restaurants and bars of California and New York are closing or are closed and all the people that work there are hourly wage. How how long do you think they will still have homes? Not trying to be alarmist but I also don’t see how people making an hourly wage are going to continue living in their very expensive states without income.
    - jedberg 7y ago
      Unless the government backstops it, they won't. It is and will be a huge problem. Some states are banning evictions for a few months, so at least there is that option. But it just means they'll be homeless in June instead of April.
    - sp332 7y ago
      Most NYC landlords have agreed to a 90-day hold on all evictions. So... about 90 days I guess.
- jacurtis 7y ago
  Self-quarantine means they send you home and tell you not to leave for 2 weeks. Unless you are in such an extreme case that you need a respirator or something, in which case they will hospitalize you and you might be around other diseased victims, but if you are in that condition then it is probably not a false positive. There is a shortage of hospital beds worldwide right now, so they are sending everyone home unless hospitalization is considered life-saving.

fma 7y ago

You may have misheard the MD. The current tests have a very low false positive rate. That means if the test says you have Coronavirus, you have it. There's no "burden". Where the tests are "not very accurate" is the false negative. The false negative rate can be as high as 50-60%, depending on tests and how it's administered. Sometimes they will conduct the test twice to improve accuracy. The Roche ones recently approved have a lower negative test rate (10%?) Edit: I removed my mention of 0% false positive rate because nothing in life is absolute.

whatshisface 7y ago
A 0% false positive rate is not possible. What if they switch your sample with someone else's while it's being handled by a human? Edit: >That means if the test says you have Coronavirus, you have it. This line implies the parent comment is talking about the false positive rate of the entire testing process that results in you being told you're infected, not PCR as a platonic ideal, theoretical process.
- irishsultan 7y ago
  That's still not a false positive rate of the test. But I agree that 0% false positive rates are going to be nearly impossible to achieve (for just about anything that isn't mathematics).
  - deleted 7y ago
    [deleted]
- joking 7y ago
  That’s a protocol fault and has nothing to do with the accuracy of the test
- fma 7y ago
  From the FDA itself. Note how firm they are in regards to a positive, vs how cautious they are in regards to a negative. If you have COVID-19 RNA in your body...you have the virus. What does it mean if the specimen tests positive for the virus that causes COVID-19? A positive test result for COVID-19 indicates that RNA from SARS-CoV-2 was detected, and the patient is infected with the virus and presumed to be contagious What does it mean if the specimen tests negative for the virus that causes COVID-19? A negative test result for this test means that SARSCoV-2 RNA was not present in the specimen above the limit of detection. However, a negative result does not rule out COVID-19 and should not be used as the sole basis for treatment or patient management decisions. A negative result does not exclude the possibility of COVID-19. https://www.fda.gov/media/135662/download https://www.fda.gov/media/135662/download