There are about 1,000 COVID-19 patients currently in Tennessee hospitals, a key marker closely watched by health care leaders and state government. Vanderbilt’s Health Policy arm predicted Tennessee would hit the mark almost to the day. John Graves, associate professor of Health Policy and Medicine at Vanderbilt University, says their models are meant to help policymakers see a range of possibilities and prepare for them but those projections are getting harder to make.

He spoke recently with WPLN News’ Jason Moon Wilkins.

Jason Moon Wilkins: You have seen this rise in hospitalizations impacting things on the local level already. Williamson Medical Center, for example, announced it’s suspending elective surgeries again, as it did during the initial shut down. Do you see more of these kinds of actions coming in the next week or so?

John Graves: Yeah, when I think about what issues a sustained increase in COVID hospitalizations raises for the health care system, I think about it in terms of staffing and in terms of the other side of the equation, for me as a potential patient or if I had a loved one who’s a patient. So those are the kind of considerations that I’m thinking about more now, as opposed to the binary question of capacity. Because our health care system — and especially hospitals — are used to operating at or near capacity. But the question now is that we have a sustained increase in this novel disease that didn’t exist eight months ago, and as more and more patients are coming into the hospital with complications related to this disease, it raises the questions of whether we can have that kind of sustained high level of staffing that’s needed to address not only those patients but everybody else coming in the door.

JMW: Do you think that the reaction — that the moves made both on the state and local level — were informed by that modeling? Do you think they made decisions that would help to slow the spread?

John Graves: I can’t speak directly to whether or not our modeling informed those decisions. I would hope that it did. But what is making things really difficult right now — in terms of modeling, but also just policy making in general — is the amount of delay that we’re seeing nationwide … between when somebody is tested and when their results come back to them. Right now, people are waiting five [and] up to 10 days for those results. And that is a significant increase over the time period in May. And what that means is that … our vision of where the virus is in the state right now is receding more and more into our rearview mirror.

JMW: And to that point, we know that there are some indicators that lag behind the number of cases

JG: Hospitalizations is a key figure that we at Vanderbilt have really been honing on. Other models out there tend to focus on things like deaths, but that’s so far downstream of when you could actually intervene that we’ve really focused more on the hospitalization question. Because it at least gives you somewhat of enough time to reverse course and possibly put in additional measures to mitigate transmission of the virus

JMW: We’ve crossed this threshold (1,000 concurrent hospitalizations). Is there a next number? Is there something that could be on the horizon that is another worrying mark that you have your eye on?

JG: Well, I think a focus really has to be at the regional level. So the analogy that I always think of is in terms of an ice cube tray filling up with water. … Individual hospitals, you can think of as a compartment in that ice cube tray, and every compartment is starting to fill up with water. But no one compartment is overfull at this point. And so the rise in hospitalizations that we’ve seen especially over the last three to four weeks have occurred in facilities that, before then, really only had a handful of COVID-19 patients. So now they’re first getting their first exposure to having a sustained number of COVID patients in their facility. And in addition to that, we’re seeing some of the more urban hospitals starting to have to build out and think about how they’re going to accommodate additional COVID patients and also meet all the other care needs of the community in terms of elective procedures, emergencies, etc.

JMW: Is there anything else you’re noticing right now?

JG: There is kind of a popular perception, which is to some degree correct, that a lot of the cases are concentrated among young individuals. And we’ve seen that very much bear out, but only in certain large urban areas like Nashville and Memphis. But in other more rural areas of the state, what we’re seeing is the footprint of the virus really being more spread out across age ranges. And along with that, we’ve seen hospitalizations rise as we’ve seen more older people and people with co-morbidities infected. And so that just bears watching.

It’s not the case everywhere that it’s just a young person issue, with a lot of 20- and 30-year-olds becoming infected. In many areas, that footprint really kind of covers the entire age distribution.