Anonymous wrote:

Anonymous wrote:How is medical testing of a child without a parent or guardian's affirmative consent legal?

Also, politically, if you've got a significant population of parents who distrust the medical field based on racism, are they going to be cool with their kids being tested without their consent?

It’s probably not. DCPS/DC likely calculated that they would prefer to lose a lawsuit than to deal with the public pressure about testing. That’s what happens when you make policy in reponse to twitter rants, town halls, and “concerned parents” instead of just good policy.

Anonymous wrote:How is medical testing of a child without a parent or guardian's affirmative consent legal?

Also, politically, if you've got a significant population of parents who distrust the medical field based on racism, are they going to be cool with their kids being tested without their consent?

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Shield test's negativity (or "specificity") rate is 98.9%, according to themselves (slide 4): https://www.iasaedu.org/cms/lib/IL01923163/Centricity/Domain/4/SHIELD%20IL%20IDPH%20overview%20050621.pdf

That means that the test correctly returns a negative result 98.9% of the time when the person is truly negative, and returns a "false positive" 1.1% of the time.

The Washington Post article posted earlier:

"Rapid antigen and saliva PCR tests, which are frequently used in schools, can have a false positive rate of 1 or 2 percent. That may sound low, but statisticians know that, when testing in a setting of low prevalence of disease, even a single-digit false-positive rate can be extremely problematic."

This study uses a slightly less specific test (the BinaxNow rapid test), which has a specificity of 98.5% (https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month)


The ASM study shows that with a similar test specificity, and low PREVALENCE rates (0.1% to 1.0%), the percentage of positive tests that are false is between 60 and 94% (it's lower when the prevalence is higher). https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Sensitivity-Is-Not-the-Whole-St

SO WHAT IS PREVALENCE DURING DELTA?

During delta and with twice weekly testing (so a lot of tests), the UK found a prevalence rate in schools of 0.27% in primary schools and 0.42% in secondary schools in June, 2021. Note that they didn't mask, and don't have vaccination approval for the 12-15 year olds. They did of course do other mitigation measures related to the testing. I offer this as it seems to be one of the only studies of PREVALENCE in schools, during delta, where there was lots of testing. https://www.gov.uk/government/news/covid-19-study-finds-lower-prevalence-in-schools

PREVALENCE outside of schools in the UK during early delta (June 24 to July 12) was 0.63%. (https://www.medicalnewstoday.com/articles/covid-19-in-england-rising-infections-as-delta-variant-takes-hold#Delta-surge).

How does that PREVALENCE compare to covid CASE RATES (which is what we all obsessively look at in DC)? Between June 24 and July 12, UK’s 7-day case rates per 100,000 went from 145 to 358 (https://coronavirus.data.gov.uk/details/cases). In DC terms (of cases per day instead of 7 days) that is about 20/100,000 per day to 51/100,000 per day.

The point being that we likely have low prevalence + Probably even lower in schools as that's been true consistently + test has a specificity greater than 1% = whole lot of false positives.

Sigh. Didn’t even look at this particular test’s specificity plus secondary testing by this lab as a mitigant for false positives. DC has actually entered into a pretty promising relationship here. Wish it was better publicized though.

The particular tests specificity is literally cited above.

Wrong. Shield T3 is greater than 99% and they retest positives. The link to the actual site has been posted numerous times.

Further, we test for three genes present in COVID-19 (vs. one gene for some other tests), with a specificity of 99.8-99.9% and very, very few false positives.
https://www.shieldt3.com/shield-t3/frequently-asked-questions/

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Shield test's negativity (or "specificity") rate is 98.9%, according to themselves (slide 4): https://www.iasaedu.org/cms/lib/IL01923163/Centricity/Domain/4/SHIELD%20IL%20IDPH%20overview%20050621.pdf

That means that the test correctly returns a negative result 98.9% of the time when the person is truly negative, and returns a "false positive" 1.1% of the time.

The Washington Post article posted earlier:

"Rapid antigen and saliva PCR tests, which are frequently used in schools, can have a false positive rate of 1 or 2 percent. That may sound low, but statisticians know that, when testing in a setting of low prevalence of disease, even a single-digit false-positive rate can be extremely problematic."

This study uses a slightly less specific test (the BinaxNow rapid test), which has a specificity of 98.5% (https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month)


The ASM study shows that with a similar test specificity, and low PREVALENCE rates (0.1% to 1.0%), the percentage of positive tests that are false is between 60 and 94% (it's lower when the prevalence is higher). https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Sensitivity-Is-Not-the-Whole-St

SO WHAT IS PREVALENCE DURING DELTA?

During delta and with twice weekly testing (so a lot of tests), the UK found a prevalence rate in schools of 0.27% in primary schools and 0.42% in secondary schools in June, 2021. Note that they didn't mask, and don't have vaccination approval for the 12-15 year olds. They did of course do other mitigation measures related to the testing. I offer this as it seems to be one of the only studies of PREVALENCE in schools, during delta, where there was lots of testing. https://www.gov.uk/government/news/covid-19-study-finds-lower-prevalence-in-schools

PREVALENCE outside of schools in the UK during early delta (June 24 to July 12) was 0.63%. (https://www.medicalnewstoday.com/articles/covid-19-in-england-rising-infections-as-delta-variant-takes-hold#Delta-surge).

How does that PREVALENCE compare to covid CASE RATES (which is what we all obsessively look at in DC)? Between June 24 and July 12, UK’s 7-day case rates per 100,000 went from 145 to 358 (https://coronavirus.data.gov.uk/details/cases). In DC terms (of cases per day instead of 7 days) that is about 20/100,000 per day to 51/100,000 per day.

The point being that we likely have low prevalence + Probably even lower in schools as that's been true consistently + test has a specificity greater than 1% = whole lot of false positives.

Sigh. Didn’t even look at this particular test’s specificity plus secondary testing by this lab as a mitigant for false positives. DC has actually entered into a pretty promising relationship here. Wish it was better publicized though.

The particular tests specificity is literally cited above.

Wrong. Shield T3 is greater than 99% and they retest positives. The link to the actual site has been posted numerous times.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Shield test's negativity (or "specificity") rate is 98.9%, according to themselves (slide 4): https://www.iasaedu.org/cms/lib/IL01923163/Centricity/Domain/4/SHIELD%20IL%20IDPH%20overview%20050621.pdf

That means that the test correctly returns a negative result 98.9% of the time when the person is truly negative, and returns a "false positive" 1.1% of the time.

The Washington Post article posted earlier:

"Rapid antigen and saliva PCR tests, which are frequently used in schools, can have a false positive rate of 1 or 2 percent. That may sound low, but statisticians know that, when testing in a setting of low prevalence of disease, even a single-digit false-positive rate can be extremely problematic."

This study uses a slightly less specific test (the BinaxNow rapid test), which has a specificity of 98.5% (https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month)


The ASM study shows that with a similar test specificity, and low PREVALENCE rates (0.1% to 1.0%), the percentage of positive tests that are false is between 60 and 94% (it's lower when the prevalence is higher). https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Sensitivity-Is-Not-the-Whole-St

SO WHAT IS PREVALENCE DURING DELTA?

During delta and with twice weekly testing (so a lot of tests), the UK found a prevalence rate in schools of 0.27% in primary schools and 0.42% in secondary schools in June, 2021. Note that they didn't mask, and don't have vaccination approval for the 12-15 year olds. They did of course do other mitigation measures related to the testing. I offer this as it seems to be one of the only studies of PREVALENCE in schools, during delta, where there was lots of testing. https://www.gov.uk/government/news/covid-19-study-finds-lower-prevalence-in-schools

PREVALENCE outside of schools in the UK during early delta (June 24 to July 12) was 0.63%. (https://www.medicalnewstoday.com/articles/covid-19-in-england-rising-infections-as-delta-variant-takes-hold#Delta-surge).

How does that PREVALENCE compare to covid CASE RATES (which is what we all obsessively look at in DC)? Between June 24 and July 12, UK’s 7-day case rates per 100,000 went from 145 to 358 (https://coronavirus.data.gov.uk/details/cases). In DC terms (of cases per day instead of 7 days) that is about 20/100,000 per day to 51/100,000 per day.

The point being that we likely have low prevalence + Probably even lower in schools as that's been true consistently + test has a specificity greater than 1% = whole lot of false positives.

Sigh. Didn’t even look at this particular test’s specificity plus secondary testing by this lab as a mitigant for false positives. DC has actually entered into a pretty promising relationship here. Wish it was better publicized though.

The particular tests specificity is literally cited above.

Wrong. Shield T3 is greater than 99% and they retest positives. The link to the actual site has been posted numerous times.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.

Delta doesn’t change math.

Yes, it does. It changes the prevelance and also likely there are far more asymptomatic cases right now than there were before so prevelance is higher than we are thinking.

And prevalence during delta in the UK was 0.63% (cite above in the thread), or about half that in primary schools (also cite above in thread).

That's "low prevalence" for the math of surveillance testing and false positives.

Also cited above, a test that has 1.5% of its tests be false positives + prevalence rates of 1.0% = 60% of positive tests are false positives

Can this not be mitigated by always retesting? And or applying a traditional PCR test?

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Shield test's negativity (or "specificity") rate is 98.9%, according to themselves (slide 4): https://www.iasaedu.org/cms/lib/IL01923163/Centricity/Domain/4/SHIELD%20IL%20IDPH%20overview%20050621.pdf

That means that the test correctly returns a negative result 98.9% of the time when the person is truly negative, and returns a "false positive" 1.1% of the time.

The Washington Post article posted earlier:

"Rapid antigen and saliva PCR tests, which are frequently used in schools, can have a false positive rate of 1 or 2 percent. That may sound low, but statisticians know that, when testing in a setting of low prevalence of disease, even a single-digit false-positive rate can be extremely problematic."

This study uses a slightly less specific test (the BinaxNow rapid test), which has a specificity of 98.5% (https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month)


The ASM study shows that with a similar test specificity, and low PREVALENCE rates (0.1% to 1.0%), the percentage of positive tests that are false is between 60 and 94% (it's lower when the prevalence is higher). https://asm.org/Articles/2020/November/SARS-CoV-2-Testing-Sensitivity-Is-Not-the-Whole-St

SO WHAT IS PREVALENCE DURING DELTA?

During delta and with twice weekly testing (so a lot of tests), the UK found a prevalence rate in schools of 0.27% in primary schools and 0.42% in secondary schools in June, 2021. Note that they didn't mask, and don't have vaccination approval for the 12-15 year olds. They did of course do other mitigation measures related to the testing. I offer this as it seems to be one of the only studies of PREVALENCE in schools, during delta, where there was lots of testing. https://www.gov.uk/government/news/covid-19-study-finds-lower-prevalence-in-schools

PREVALENCE outside of schools in the UK during early delta (June 24 to July 12) was 0.63%. (https://www.medicalnewstoday.com/articles/covid-19-in-england-rising-infections-as-delta-variant-takes-hold#Delta-surge).

How does that PREVALENCE compare to covid CASE RATES (which is what we all obsessively look at in DC)? Between June 24 and July 12, UK’s 7-day case rates per 100,000 went from 145 to 358 (https://coronavirus.data.gov.uk/details/cases). In DC terms (of cases per day instead of 7 days) that is about 20/100,000 per day to 51/100,000 per day.

The point being that we likely have low prevalence + Probably even lower in schools as that's been true consistently + test has a specificity greater than 1% = whole lot of false positives.

Sigh. Didn’t even look at this particular test’s specificity plus secondary testing by this lab as a mitigant for false positives. DC has actually entered into a pretty promising relationship here. Wish it was better publicized though.

The particular tests specificity is literally cited above.

Wrong. Shield T3 is greater than 99% and they retest positives. The link to the actual site has been posted numerous times.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.

Delta doesn’t change math.

Yes, it does. It changes the prevelance and also likely there are far more asymptomatic cases right now than there were before so prevelance is higher than we are thinking.

And prevalence during delta in the UK was 0.63% (cite above in the thread), or about half that in primary schools (also cite above in thread).

That's "low prevalence" for the math of surveillance testing and false positives.

Also cited above, a test that has 1.5% of its tests be false positives + prevalence rates of 1.0% = 60% of positive tests are false positives

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.

Delta doesn’t change math.

Yes, it does. It changes the prevelance and also likely there are far more asymptomatic cases right now than there were before so prevelance is higher than we are thinking.

And prevalence during delta in the UK was 0.63% (cite above in the thread), or about half that in primary schools (also cite above in thread).

That's "low prevalence" for the math of surveillance testing and false positives.

Also cited above, a test that has 1.5% of its tests be false positives + prevalence rates of 1.0% = 60% of positive tests are false positives

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.

Delta doesn’t change math.

Yes, it does. It changes the prevelance and also likely there are far more asymptomatic cases right now than there were before so prevelance is higher than we are thinking.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.

Delta doesn’t change math.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:For those who don't like the date of April, 2020, here's another article from infectious disease specialists from July, 2021:

https://www.usnews.com/news/health-news/articles/2021-07-14/why-covid-19-screening-should-be-used-sparingly-in-schools

Why We Shouldn’t Blindly Screen Students for COVID-19 This Fall
When case rates are low, the majority – and sometimes even the vast majority – of positive test results are false-positives.

The DESE testing program and others across the state and across the country have shown us that the probability of COVID-19 in asymptomatic students attending in-person learning was consistently low – less than 0.5% – even before widespread vaccination. Using 0.5 as a (very) generous overestimate and a close-to-perfect (99% specific) diagnostic test, that means for every one true positive test, three will be false-positive. The true specificity of some polymerase chain reaction (PCR) tests is probably closer to 95% (in other words, still very good, but not quite so close to perfect). This more realistic estimate increases the proportion of false-positives test results even more – up to 14 false-positives for every real case of COVID-19 identified by the screening program. As case rates continue to decline, the ratio of real cases to false-positives only gets worse (and worse). Assuming a rate of 1 in 1,000 or 0.1% and a nearly perfect test, there are 14 false-positive tests for every real case found by a screening testing program, and 71 if we use the more realistic estimate of 95% specificity.

Thank you for posting this article.

That article is pre-Delta and describes an environment of declining case rates.