Why The US Data Was Changed

April 14 -15 Change in United States Data

Following new CDC guidelines: “As of April 14, 2020, CDC case counts and death counts include both confirmed and probable cases and deaths. This change was made to reflect an interim COVID-19 position statement issued by the Council for State and Territorial Epidemiologists on April 5, 2020. The position statement included a case definition and made COVID-19 a nationally notifiable disease.

A confirmed case or death is defined by meeting confirmatory laboratory evidence for COVID-19. A probable case or death is defined by i) meeting clinical criteria AND epidemiologic evidence with no confirmatory laboratory testing performed for COVID-19; or ii) meeting presumptive laboratory evidence AND either clinical criteria OR epidemiologic evidence; or iii) meeting vital records criteria with no confirmatory laboratory testing performed for COVID19″ [source]

This change is a further example of one of the many reasons why the label “confirmed cases” (used by some to designate total cases) is incorrect (see definitions for more details). The US CDC (and Worldometer) has always used the label “Total Cases.” Canada is another example where the “total number includes publicly reported confirmed and probable cases [source]

On April 14, New York City reported 3,778 additional deaths that have occurred since March 11 and have been classified as “probable,” defined as follows: “decedent […] had no known positive laboratory test for SARS-CoV-2 (COVID-19) but the death certificate lists as a cause of death “COVID-19” or an equivalent” [source]. 

From April 14 onward, New York City has provided – and will continue to provide –  the updated number of probable deaths in its daily reports.

On April 15, in the daily press briefing, New York Governor Cuomo said that “we will begin reporting all categories of fatalities pursuant to new CDC guidelines and are contacting facilities to get updated numbers.” He also added that there may be additional people who died that have not been counted because not in a hospital. In the April 15 update, the New York State Department of Health official website had still not included (nor reported separately) the additional “probable” deaths reported by New York City the day before. On April 16, when asked about the issue, New York State officials commented on their decision to not add the New York City probable deaths in the official State count saying that probable deaths have been reported by New York City in a new and separate category, without adding the two numbers (confirmed and probable) together into a single category.

Worldometer is following the new CDC guideline of including both probable and confirmed in the total case and death counts [source]

As with similar instances in the past (with other countries), we have added the additional data on the day it was reported. If and when the historical distribution is provided, we will make the needed adjustments. Alternatively, we are considering modeling the distribution on the progression of confirmed deaths in New York City from March 11 to April 14.

Finally, since every probable death necessarily implies a probable case, logic mandates that the adjustment be made to both deaths and cases, and not only to deaths. We have now adjusted April 14, April 15, and current data for New York State and the United States accordingly.

Learn more Worldometer COVID-19 Data

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