5 ms·

The questions to ask for any test: - What is the false positive rate? - What is the false negative rate? - Considering the above, what is the efficacy of mas

The questions to ask for any test: - What is the false positive rate? - What is the false negative rate? - Considering the above, what is the efficacy of mass testing? (Not saying it is or isn't effective, hard numbers are necessary)

sho74 7y ago
Yup I have been wondering about this too. If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Other weird thought I had was how does security deal with some lunatic who gets tested positive and runs around infecting others...just walks into some critical hub like a hospital and pat's everyone on the back.
- elorant 7y ago
  At the very least you can isolate those 100 people and their contacts instead of isolating the whole freaking county. Lockdowns work but there is a huge burden to the economy.
- mattnewton 7y ago
  > Yup I have been wondering about this too. If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Pick the 10 most likely to develop complications due to age or comorbidity and quarantine the rest so that you don’t get 200 more next week. We’re still in the “stop the bleeding” phase of treatment.
  - scrollaway 7y ago
    Triage usually dictates that the ones most likely to die from the illness, especially if they're old, get lower priority than those that can be treated at a greater success rate, and who are more likely to live longer and healthier as a result. This is the procedure at most hospitals. You give the beds to those who need them, and are most likely to "make good use" of them (= not "waste" them by likely dying anyway; sorry for the atrocious wording)
    - mattnewton 7y ago
      Sure; the idea is that testing allows officials to make decisions about how best to use the resource you have, both in terms of hospital beds and quarantine.
- vkou 7y ago
  > If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Isolate those 100 people. Then use whatever methodology[1] your society uses to allocated hospital beds to the ones that will get sick enough to need them. Just because you test positive doesn't mean you'll need a hospital bed. Oh, and while you're at it, ban public gatherings, and close schools. Because if 100 people tested positive, there's probably another 200-300 people walking around, infecting others. [1] First-come-first-serve, youngest-and-healthiest-first, whomever-can-pay-more are the most popular methodologies for this.
- tim333 7y ago
  >lunatic who gets tested positive and runs around infecting others It's happened. Criminal charges for assault probably work.
amasad 7y ago
There is already studies on that coming out of Wuhan and it's not looking good. Here are some highlights from my own research. Note that RT-PCR is what the CDC recommends and what most nations are using for testing COVID-19: > the total positive rate of RT-PCR for throat swab samples was reported to be about 30% to 60% at initial presentation [1] > In patients with negative RT-PCR results, 75% (308/413) had positive chest CT findings; of 308, 48% were considered as highly likely cases, with 33% as probable cases [2] > For patients with negative RT-PCR tests, more than 70% had typical CT manifestations. On the one hand, due to the overlap of CT imaging features between COVID-19 and other viral pneumonia, false-positive cases of COVID-19 can be identified on chest CT. Nevertheless, considering the rapidly spreading epidemic of COVID-19, the priority was to identify any suspicious CT case in order to isolate the patients and administer appropriate treatment [3] > Conclusions: In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives [4] [1][2][3]: https://pubs.rsna.org/doi/full/10.1148/radiol.2020200642 https://pubs.rsna.org/doi/full/10.1148/radiol.2020200642 [4]: https://www.ncbi.nlm.nih.gov/pubmed/32133832 https://www.ncbi.nlm.nih.gov/pubmed/32133832
Gatsky 7y ago
Under the circumstances, a test better than totally useless is good enough. Unless there is an alternative immediately available. Which there isn’t.

sho74 7y ago

Yup I have been wondering about this too. If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Other weird thought I had was how does security deal with some lunatic who gets tested positive and runs around infecting others...just walks into some critical hub like a hospital and pat's everyone on the back.

elorant 7y ago
At the very least you can isolate those 100 people and their contacts instead of isolating the whole freaking county. Lockdowns work but there is a huge burden to the economy.
mattnewton 7y ago
> Yup I have been wondering about this too. If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Pick the 10 most likely to develop complications due to age or comorbidity and quarantine the rest so that you don’t get 200 more next week. We’re still in the “stop the bleeding” phase of treatment.
- scrollaway 7y ago
  Triage usually dictates that the ones most likely to die from the illness, especially if they're old, get lower priority than those that can be treated at a greater success rate, and who are more likely to live longer and healthier as a result. This is the procedure at most hospitals. You give the beds to those who need them, and are most likely to "make good use" of them (= not "waste" them by likely dying anyway; sorry for the atrocious wording)
  - mattnewton 7y ago
    Sure; the idea is that testing allows officials to make decisions about how best to use the resource you have, both in terms of hospital beds and quarantine.
vkou 7y ago
> If my community has 10 beds and 2 docs what is anyone supposed to do if there are 100 positives? Isolate those 100 people. Then use whatever methodology[1] your society uses to allocated hospital beds to the ones that will get sick enough to need them. Just because you test positive doesn't mean you'll need a hospital bed. Oh, and while you're at it, ban public gatherings, and close schools. Because if 100 people tested positive, there's probably another 200-300 people walking around, infecting others. [1] First-come-first-serve, youngest-and-healthiest-first, whomever-can-pay-more are the most popular methodologies for this.
tim333 7y ago
>lunatic who gets tested positive and runs around infecting others It's happened. Criminal charges for assault probably work.

amasad 7y ago

There is already studies on that coming out of Wuhan and it's not looking good. Here are some highlights from my own research. Note that RT-PCR is what the CDC recommends and what most nations are using for testing COVID-19: > the total positive rate of RT-PCR for throat swab samples was reported to be about 30% to 60% at initial presentation [1] > In patients with negative RT-PCR results, 75% (308/413) had positive chest CT findings; of 308, 48% were considered as highly likely cases, with 33% as probable cases [2] > For patients with negative RT-PCR tests, more than 70% had typical CT manifestations. On the one hand, due to the overlap of CT imaging features between COVID-19 and other viral pneumonia, false-positive cases of COVID-19 can be identified on chest CT. Nevertheless, considering the rapidly spreading epidemic of COVID-19, the priority was to identify any suspicious CT case in order to isolate the patients and administer appropriate treatment [3] > Conclusions: In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives [4] [1][2][3]: https://pubs.rsna.org/doi/full/10.1148/radiol.2020200642 https://pubs.rsna.org/doi/full/10.1148/radiol.2020200642 [4]: https://www.ncbi.nlm.nih.gov/pubmed/32133832 https://www.ncbi.nlm.nih.gov/pubmed/32133832

Gatsky 7y ago

Under the circumstances, a test better than totally useless is good enough. Unless there is an alternative immediately available. Which there isn’t.