As the number of patients in US hospitals with Covid-19 hits new records doctors and public health experts are asking whether the headline number is still a reliable indicator of the pandemic’s trajectory given that some patients are being admitted for other reasons.
Based on data from the US Department of Health and Human Services, the current seven-day rolling average of patients hospitalised with Covid-19 in the US is 155,677, exceeding the peak of 139,279 patients in January 2021.
But Omicron infections are now so widespread that some people going to hospital are seeking treatment for something else are testing positive for Covid-19 upon arrival. That threatens to complicate the link between severe illness and death and hospitalisations, which have until now served as a reliable early indicator of how the pandemic is progressing.
“We are seeing a lot of people coming to the hospital for other reasons who just happen to find they have Covid,” said Jennifer Caputo-Seidler, a doctor at Tampa General Hospital in Florida. “They may have a broken leg but are still testing positive.”
Caputo-Seidler said hospitalisation numbers no longer give a full picture of what is happening with the virus because of these “incidental” admissions of Covid patients.
David Dowdy, an epidemiologist at Johns Hopkins School of Public Health, said it was difficult to measure the impact of people who test positive for the virus in hospital despite attending for another reason because of a lack of data and patchy reporting.
“In real time, we’re largely stuck with having to make mental adjustments — there is no reliable method that I’m aware of to ‘factor out’ these incidental admissions,” he added.
Another complicating factor is that Omicron infections are less severe than some other variants such as Delta, while many people now have better immune protection as a result of vaccinations and prior infections.
While cases and hospitalisations have increased 320 per cent and 116 per cent, respectively in the past three weeks, the number of Covid patients in the ICU has not grown as quickly, increasing only 51 per cent.
Statewide data on incidental admissions has only recently become available in places such as New York and Massachusetts, which have started collecting the data. In New York state, 42 per cent of Covid hospitalisations in New York state are incidental while in Los Angeles county the figure is two-thirds. In Florida, the Jackson Health System reported that out of their current 508 Covid-positive patients, 53 per cent were incidental admissions.
National hospitalisation data does not include information about severity of illness, non-Covid admissions or vaccination status. The CDC has used Covid-Net, a network of 250 hospitals in 14 states to examine some of these trends, but this information has not been reported in good time.
Still, the high number of infected patients flooding into hospitals is severely taxing the healthcare system because of the requirement for isolation rooms, personal protective equipment and the toll on hospital employees, many of whom are themselves off sick or isolating after contracting the virus.
According to hospital capacity status data from a team of public health experts led by emergency room doctor Jeremy Faust, 1,038 US counties are at or will soon reach hospital capacity, compared to 825 counties that have capacity.
Responding to strained hospitals in their states, Maryland Governor Larry Hogan declared a state of emergency on January 4 and Virginia Governor Ralph Northam issued an emergency order on January 10 to provide relief to healthcare providers.
The highly infectious Omicron variant is poised to further propel rising hospitalisation numbers. The University of Texas at Austin Covid-19 Modeling Consortium forecasts that the massive surge in infections will result a 1.2 to 2.6 fold jump in hospitalisation rates.
“Hospitals are already struggling. It means that Covid cases aren’t going to get the safe and effective treatment that they need,” said Lauren Ancel Meyers, the executive director of the Texas consortium. “And also that anyone who needs healthcare for any reason may or may not be able to access the care they need.”
At Tampa General, the number of patients with Covid has skyrocketed from just under 10 in the week before Christmas to 158 this week, piling pressure on staff entering a third year of crisis.
“Staffing is a huge problem because we have tons of people who are infected themselves and quarantining,” said Caputo-Seidler.
Eric Topol, director of the Scripps Research Translational institute, said hospitalisation rates would remain an important data point in the pandemic because they showed the stress on the healthcare system. Dismissing a Covid infection as “incidental” is too simplistic because of limited data and the severe complications the virus can cause, he added.
“The idea that 40 per cent are incidental, well who knows? There are no careful reviews of such cases and there are many that are likely due to Covid,” said Topol. “We had a patient admitted today at our centre with chronic, obstructive lung disease. The patient came in breathless and tested positive for Covid — so the question is, how does that patient get classified?”
Covid cases continue to surge nationwide in the US with no clear peak in sight, although there are some signs of levelling off in North Eastern states that were first hit by Omicron. A significant proportion of Americans are still vulnerable as only 62 per cent of the population is fully vaccinated while just 22 per cent have received a booster dose, according to data from the CDC.
Topol said low vaccination and booster rates in the US meant hospitalisation rates would continue to soar and the nation may not see the type of decoupling of cases and severe disease that some European nations, such as Portugal, Norway and Denmark have experienced with Omicron.
“We are way behind in boosters . . . and that’s the main thing that protects people from hospitalisation,” Topol said.