New York City hits 3% positive test rate. Or did he?

Three percent.

It is currently New York City’s most important number, a critical threshold that raises sanctions in response to the coronavirus by state and local governments. The mayor of New York has closed public schools at 3 percent. The governor says that as a result of the persistent percent percent level in the city, indoor dining will be banned, gyms and hair salons will be closed, and 25-person hats will be placed in houses of worship even as the holidays approach.

But as important as that number is, it seems the city and state may not be able to agree on whether we are still there.

The same situation has prevailed in the past week, with Mayor Bill de Blasio saying that one percent has been violated, while the governorship. Andrew M. Kumo said he is below this. Each relies on its own statistics, which are compiled and reported differently on the tests to be included in the calculation.

The discrepancy could be surprising: for example, on Sunday, the city said its seven-day average is 3.09 percent. Mr Kumo’s office fees, however, put the city’s rate down more than half a point, to 2.54 per cent.

In a way, of course, not all numbers are the same, as Mr. Cuomo’s statistics from the state Department of Health govern the wide range of activities and businesses in all areas of New York. But Mr Cuomo gave local school districts the right to set their own parameters for school closures, and Mr de Blasio, who controls the school system, set the percentage as that level.

And so, in the end, it was the number of cities that caused individual education in the nation’s largest school system to stall.

Why can’t they agree on whether we are percent percent?

The reason for the discrepancy is included in both tests and the time frame in which the statistics are reported is given different numbers each day by the mayor and governor.

It is the latest inconsistent message between the two rivals over the whole epidemic, leading to a level of inactivity and confusion in the reaction.

On Sunday, Mr Kumo suggested that calculating its positive rate in the city was “confusing and unnecessary” and also “irrelevant” because the state’s numbers would rule out any broader restrictions.

State and city health departments, in fact, have different accounting rules for tracking the spread of the virus. The result of the state examination treats new cases arising the next day. The date of each new case in the city comes, which was given a sample of the day.

So if an infected person goes to the clinic on Monday to have his nose broken, the sample is often delivered to the laboratory where it is tested. If those results are reported to health officials on Wednesday, the state and city will record them separately. The state will include it with a count of new cases on Wednesday, while the city will add it to Monday’s column.

The 3 percent threshold is based on a seven-day rolling average. The day on which the new case is registered is important.

Another factor also contributes to the discrepancy, which has received little attention so far: antigen tests. New York State includes tests in its official metrics. But while they are usually fast, they can detect infections in people with low viral load.

In New York City, which does not include antigen tests, polymerase prefers a higher sensitivity known as a chain reaction test. The city only includes PCR tests performed in its computational laboratory. That’s why the state – which is calculating both antigen and PCR tests – may be taller for the case overall in New York City, but the percentage of positivity is low.

PCR tests in the laboratory have long been considered the gold standard because they are unlikely to miss any infections. But some public health experts say PCR testing for coronavirus is very sensitive, resulting in coronavirus being diagnosed for people who have relatively small amounts of the virus and may not be infected.

Antigen tests, which can be done quickly and cheaply, detect bits of coronavirus protein. But they miss cases, including those that have recently been infected, which have reduced the viral load.

The difference in sensitivity between the two types of tests can lead to differences in positivity rates between city and state.

In fact, the positivity rate of the same group of people – in this case, New York City residents – may vary depending on how many antigen tests they receive as opposed to traditional PCR tests. Antigen tests can be missed in some cases when the amount of virus is still low.

Say 1000 people come to the test. Let’s assume everyone has a PCR test, and 30 percent positive, for a 3 percent positivity rate. Let us now assume that half have received the antigen test and half have received the PCR test. For a positivity rate of 2.5 percent, only 25 tests come back positive.

“We believe in our numbers and our method,” said Bill Needhardt, the mayor’s spokesman, before acknowledging the mayor’s decision to reach the percent percent threshold on Wednesday instead of adopting state metrics in last-minute bids to keep schools. Open.

“Changing the standard of public health in the middle of the morning is not a good idea for clarity and people’s confidence,” he said.

State Health Department spokesman Gary Holmes said the state recorded both types of tests, “to provide a clear probable picture of individuals diagnosed with covid in a given period.” It is necessary to isolate the person for a positive result of either PCR or antigen test.

On Sunday, Mr Kuomo said the state “conducts hundreds of thousands of antigen tests” every week, noting the frequent tests of nursing home staff, adding that “there will be a significant reduction in the database.” Coming up quick results may be even more in demand next week as people take tests before the holidays. “It’s nice to know quickly,” Mr. Kumo said.

There are other differences in how the city and the state calculate the positivity rate that also help explain why the city rate is higher.

For example, if a person takes a negative test repeatedly over a seven-day period, the city counts only one test when the positivity rate is calculated. But the state includes in its calculations all the negative tests that take place from different days.

On the other hand, when one frequently tests positive, the city includes every positive test when calculating the positivity rate. The state, however, only counts the first positive test and ignores subsequent tests.

That last variable – whether it is considered a recurring positive or not – can have a big impact on the positivity rate. Gareth Rhodes, a member of Mr. Cuomo’s coronavirus task force, estimated that about 15 or 20 percent of the positive PCR tests currently coming out of New York City were for someone who had tested positive in the past.

Why does it matter

If New York City hits percent percent based on state metrics, the governor has indicated it will enter the so-called “orange zone,” which is in the middle of three color-coded restrictions imposed by the state in early October.

Under the governor’s plan, the so-called “red zone” is subject to the most difficult restrictions, including mass gatherings, indoor dining and individual education. Important businesses will close and religious services will be limited to 25 per cent of worship houses or 10 people, the number of which is low.

The “Orange Zone” – which the governor says is at risk of entering the city – allows for a few large gatherings and outdoor dining, but schools close like “high-risk” financial businesses such as Neon and Gym. Precautions Zone – Properly Yellow – Allow individual classes but increase testing, and place a few tight caps on meals and gatherings.

Four of the city’s five boroughs – Queens, the Bronx, Brooklyn and Staten Island – already have yellow zones, and Mr. Cuomo said upper Manhattan could be imposed this weekend. Staten Island could also face severe sanctions.

The zone is re-evaluated after two weeks, and the entry and exit metrics in each of these zones involve complex mixing and deliberation of data: restrictions can be modified “on expert advice,” the state says, and include decisions. Depending on local hospitalization rates, or outbreaks can be detected by a single source (prison, gathering, or group residence).

Other factors may include more ambiguous standards such as “compliance and enforcement actions taken by local government” as well as “community collaboration to reduce viral spread”.

Which, of course, is the only number – such as percent percent – that can render less important.

Can the city act on its own?

Based on its metrics, New York City has already reached the 3 percent mark. Yet there will still be some time before businesses face any restrictions.

State figures alone put the city’s seven-day rolling average below that number, but New York City must break that threshold for 10 consecutive days when the city enters the “orange zone.”

Technically, the city could use a number of operations to target businesses that are contributing to the spread of the virus. For example, the city’s health department may try to close a restaurant by declaring it a public health risk.

But the governor has the power of crisis over various businesses, calling Mr de Blasio. At news conferences, the mayor sometimes takes note of the resignation, saying that some decisions regarding the conclusion should be left to the governor.

So, for now, New Yorkers will wait to hit the city 3 percent again.