A smartphone app that helps Hawaii residents discover whether they’ve been exposed to someone who has tested positive for COVID-19 has not achieved enough critical mass of users to be effective.

Developers of the AlohaSafe Alert say a minimum of 150,000 cell phone users in Hawaii need to use the exposure notification system to start markedly reducing the spread of COVID-19.

But so far, only 100,000 users have downloaded the app onto a device since it was launched in November.

The app uses new technology developed by Google and Apple to automate the time-consuming work of contact tracers. 

Much like a news or weather notification, it sends push alerts to the cellphones of any user who came in close contact — within 6 feet for a duration of at least 15 minutes — with another app user who tested positive for the virus. 

The goal is to speed up the work of discovering close contacts of people who contract COVID-19 so they can self-isolate and monitor symptoms. However, it’s a voluntary service and is only as powerful as its adoption. 

If the app is used by 15% of the population, Oxford researchers using statistical modeling found it can lead to an 8% reduction in COVID-19 infections and a 6% reduction in deaths. 

Hawaii will arrive at that “sweet spot” when 150,000 cell phone users have downloaded and activated the app, said Lynelle Marble, executive director of the Hawaii Executive Collaborative, which is helping to promote the app.

This goalpost metric represents 15% of smartphone users in Hawaii, not 15% of the overall population.

“If we get to 150,000 users, that’s when we start seeing the app’s effectiveness,” Marble said. “It’s only as good as the number of people downloading it and using it, and we’re so close with vaccines coming up and hopefully this is just that tool that can help us get there.”

The app is mainly being promoted through volunteer-powered community outreach, as well as social media. But in some cases, use of the app is required for travelers who wish to bypass the state’s mandatory 10-day quarantine.

Maui County instructs all travelers following the state’s Safe Travels program to download and activate the AlohaSafe Alert, or another exposure notification system powered by the Google-Apple technology, on their smartphones.

“It’s only as good as the number of people downloading it and using it.” — Lynelle Marble of the Hawaii Executive Collaborative

Those who fail to show proof that they’ve activated the app to airport screeners — even if they have a negative COVID-19 test result — must quarantine, according to the county’s emergency rules aimed at reducing the spread of COVID-19.

A general fear that personal information collected by apps could be hacked or repurposed for other uses drove developers to create an app that keeps users anonymous.

Built-in privacy protections prevent the app from indicating who may have exposed you or where you may have been exposed — only that you have, in fact, been exposed. No location data is tracked.

These same protections, however, prevent app developers from discovering how many people are actually using the exposure notification system. 

“The challenge for us, because the app is anonymous and privacy was a priority in developing the technology, is it’s hard for us to measure any type of location,” Marble said. “In fact, we can’t measure use by ZIP code, we can’t measure what people are doing once they download the app — all we can measure is the number of downloads.”

More than 20 states and several other countries have already adopted similar apps powered by the Google-Apple technology. Unlike other countries, the United States does not have a national app.

Development of Hawaii’s app cost $116,000, with a $90,000 investment from the Hawaii Health Department and a $26,000 contribution from a private donor, according to Marble. 

Aio Digital assisted in the creation and rollout of the app. The DOH provided epidemiological expertise.

To raise awareness, the public-private partnership team behind the app is about to launch a social media campaign powered by local influencers, Marble said.

Companies that already have promoted the app to their employees include Hawaiian Airlines, Hawaii Pacific Health, The Queen’s Medical Center, Hawaii Medical Service Association, Zippy’s Restaurants and union groups including the Hawaii State Teachers Association. 

At Dr. Galen Chock’s pediatric practice in Honolulu, a QR code on the wall prompts patients to download a smartphone app that helps users learn whether they’ve been exposed to someone who has tested positive for COVID-19.

For Chock, who has fielded countless phone calls from patients concerned they may have been exposed to COVID-19, the exposure notification system offers a faster means of discovering potential new coronavirus infections.

“I think we should rely on the technology because it’s available,” Chock said. “But we also have to trust it.”

“From my perspective, you should treat it just like (your) friend called and said they’re COVID-positive,” Chock added.