(TNS) — The NY COVID Alert app unveiled by Gov. Andrew M. Cuomo earlier this month, which the governor touted as a technological game changer for contact tracing, has been downloaded more than 640,000 times — but the governor's office and the Department of Health have declined to turn over more detailed aggregate data that would measure the app's impact.

That additional data, which is a matter of public record, would reveal how effective the mobile app has been in tracking the spread of COVID-19 across the state, including alerting people who may have come in close contact with an infected person.

Similar versions of the same app have also been rolled out in Pennsylvania, New Jersey and Delaware. According to figures provided by those states, the app has been downloaded more than 50,000 times in Delaware , more than 220,000 times in New Jersey and more than 330,000 times in Pennsylvania.

"To date, over 630,000 New Yorkers have downloaded the COVID Alert NY app. We encourage all New Yorkers 18+ to download the app and we continue to conduct outreach to communities across the state to increase app usage," Gary Holmes, a spokesman for the New York Department of Health, said in an email. "To protect user privacy and security, the New York state Department of Health will not be disclosing information about individual notifications or exposures."

Two days after the app was launched, Cuomo's Secretary Melissa DeRosa tweeted that the app had been downloaded "over 305,400 times." In the ensuing 18 days, the app was downloaded by roughly an additional 325,000 people. It's unclear how many of those individuals may have deleted or not activated the app.

There are no laws prohibiting the state from disclosing how many exposures or individual notifications have been documented by the app. The state's own web page for the app acknowledges that none of the data requested by the Times Union contains any personal, identifiable information about users of the app. That also calls into question the assertion by Cuomo's administration that disclosure of the aggregate data would violate individual "user privacy and security," unless the app is recording that information.

The privacy policy for the app that's detailed on the state's Department of Health website says that it tracks more detailed information including active users, the number who have uploaded positive test results and the number who have been alerted of close contact with infected individuals. The governor's office and health department officials declined to provide those figures, which would help measure the productivity of the app that Cuomo's office had said cost about $700,000 to develop, with financing in part from Bloomberg Philanthropies foundation and federal funds.

The Cuomo administration's unwillingness to share the public data is part of a pattern by the governor's office on releasing data in the ongoing public health crisis. The governors administration has refused to disclose to the number of nursing home patients who were infected with COVID-19 and transferred to a hospital before dying, instead counting only those who died inside nursing homes as nursing home deaths, despite demands from politicians and outside groups for the information.

The administration also has declined to provided figures on the amount of personal protective equipment and medical supplies, including ventilators, that were in its stockpiles at the height of the pandemic. Cuomo's administration spent hundreds of millions of dollars on medical equipment and supplies that went unused at a time he had repeatedly claimed that New York could face shortages and front-line workers were running short on masks and other materials.

Pennsylvania, on the other hand, promptly responded to the Times Union with the same detailed numbers that Cuomo's office declined to provide. In Pennsylvania, with its 330,000 downloads, 107 have uploaded positive test results through the app — triggering notifications to 22 who were in sustained close contact to those people — three of whom requested calls from the Department of Health for advice, spokeswoman Maggi Mumma emailed the Times Union.

"We are proud that Pennsylvanians are finding this tool to serve as a resource to fight the spread of COVID-19," Mumma wrote. "We emphasize that the more people that download the app, the more successful it will be when notifying of exposures from COVID-19 positive individuals."

The app, called COVID Alert NY, was developed in partnership with Bloomberg Philanthropies, Google, Apple and other technology companies, and it's available for iPhone and Android. It uses the Bluetooth service on a mobile device to track when the person comes in close proximity — six feet — of others who also have the app. If a person tests positive and uploads their positive result through the app, it alerts others who have the app and were in close proximity of the infected person for at least 10 minutes.

State officials said the app does not track specific geographic location and that users are not personally identifiable from the information provided to the health department. Those under the age of 18 are not allowed to sign up for the app without clicking that it was authorized by a parent or guardian, a decision Holmes said was made on policy grounds rather than because any law prohibited it.

"It's using technology really on a level it's never been used before," Cuomo said on Oct. 1 when the app was announced. "I think it's going to give, not only bring contact tracing to a new level, but it's going to give people comfort."

But based on the level of usage thus far, it's unclear whether the app is making a measurable impact on contract tracing.

"You know, anxiety is very high. Everybody's wondering. I was next to this person ... but this can actually give you some data and facts can help reduce anxiety and that is a good thing," Cuomo had said. "Sometimes facts can increase anxiety but that's more in my position in life."

The different versions of the app work in concert, meaning if someone travels from New York through Pennsylvania, they will still be able to tell you if you have been exposed to COVID or exposed others. That may be particularly helpful over Thanksgiving and the winter holidays as travel increases, said Delaware Public Health Department communications Director Jill Fredel.

"We keep finding new avenues to get the word out there. As states enter the second or third wave — whatever wave this is or some states are obviously almost in — the immediacy will become more pronounced," Fredel said.

She said the app helps fill in the gaps of a person's memory. When doing contact tracing, people who test positive must recall where they have been and who they have had close contact with, but if more people use the app it takes away the guess work, Fredel said.

"It's really important to be able to turn that around so quickly and not have to depend on people's memories," she said.

(c)2020 the Times Union (Albany, N.Y.). Distributed by Tribune Content Agency, LLC.