Texas COVID-19 Model Could Help Hawaii Decide On Lockdown Measures

Aug 18, 2020

As Hawaii struggles to control its soaring COVID-19 numbers, it might turn to Austin, Texas where researchers built a model to forecast how different actions can affect levels of infection in the area. It could give Hawaii insights into using hospital cases to determine when it’s time to lock down.

Chair of Industrial Engineering and Management Sciences at Northwestern University and one of the researchers noted that hospital admission numbers may be more reliable than daily case counts to monitor levels of COVID infection.

“One of the problems with tracking case counts is the way people are tested, it keeps changing over time, the availability of test kits, how the specific people are selected, and how long it takes for someone to find out whether it was comes back, positive or not,” he said. 

“You can obviously track deaths but it's too late. It is a very late signal. There are a lot of places that track heads and beds in terms of total people in the hospital. But what's really what we found useful was to track new admissions. And that was a reliable signal. Because even if you track deaths, the quality of treatment is varying.”

The model aimed to show policy makers how they can keep hospitals from being overwhelmed while still continuing to reopen.

Morton explained that cocooning, or isolating vulnerable people -- including the elderly and immunocompromised-- is the key to keeping hospital capacity low.

“We had a really stringent cocooning of vulnerable populations. And if we just reduced that from like 95% effective cocooning down the 80% effective to pruning then two things happened,” he said.

“One was the total number of deaths was significantly larger. And because those high risk individuals are more likely to go to the hospital, we much more quickly hit hospital capacity. And therefore we had to have tighter triggers that ended up having us in lockdown for about twice as many total days.”

According to the model, even a 10% decrease in effective cocooning of vulnerable populations can be catastrophic for hospitals.

He said a similar model could be created for Hawaii.

However, hospitals would need to report their daily COVID-19 admissions, ICU beds and general ward beds. The state or counties would also have to track the number of people in higher risk groups.

This type of model would be helpful for policy makers, including healthcare leaders such as Hilton Raethel who warned that Hawaii’s hospitals could get overrun. 

Raethel, President of the Healthcare Association of Hawaii, which represents hospitals, echoed one of Morton’s concerns.

“We have had some deaths, that death rate is very low compared to almost every other state in the nation. So from that perspective, you're doing well, but we want to be able to continue to do well. And we want to be able to ensure that every patient who does end up in the hospital gets the appropriate level of care,” he said.

“But that becomes more and more of a challenge if more and more people become infected if they're not doing what they need to do. Which is social distancing, wearing a mask, and washing my hands etc.”

The healthcare association has its own model that’s not publicly available, but is shared with state leaders. 

As cases surge in Hawaii, a publicly shared model would help residents understand why officials are taking steps to lock down.