The worst-case scenario for COVID-19 is that hospitals become overwhelmed with patients. If too many people become seriously ill too fast, there won't be enough ICU beds and ventilators for everyone who needs them, public health officials nationwide are warning, which could cause many more deaths from the virus.
But 11 states and the District of Columbia either don't know or won't say how many COVID-19 patients have been admitted to their hospitals, according to an APM Reports survey of state health departments. Many states normally don't track that kind of data in real time, including COVID-19 hotspots like California and Washington state. Now they're scrambling to collect the information amid a global pandemic.
"It is one of the highest-priority projects we have going right now," said Kevin Wickersham, who supervises a team of epidemiologists at the Washington State Department of Health.
Without accurate data on hospitalizations, epidemiologists say, it will be difficult to understand the severity of the pandemic, predict its trajectory and to direct medical supplies where they're needed most.
"It's very concerning," said Ryan Demmer, an epidemiologist at the University of Minnesota who's been studying the effect COVID-19 has on patients with cardiovascular conditions. "We need good numbers like this to inform our infection models."
While states require laboratories to report confirmed cases of an infectious disease like COVID-19, some states don't have the systems in place to gather information on which of those patients were admitted to hospitals. With more established diseases like seasonal flu, that's not necessarily data that state officials need to have. Now they need it.
While every state reports the number of residents who have tested positive for the virus that causes COVID-19, that number is of limited value because tests have been scarce and protocols for who can get tested have repeatedly shifted. When the numbers go up, it could be because more people are being tested.
Hospitalizations, on the other hand, are what Dr. George Rutherford, a physician and University of California San Francisco epidemiologist, calls a "hard number" — a more reliable indicator of how quickly the disease is spreading and whether the extraordinary efforts some states are using to contain it are working.
Knowing how many patients with COVID-19 are winding up in which hospitals also allows local, state and federal officials to track whether hospitals can keep up with the growing number of seriously ill patients.
New York, for example, saw the number of people hospitalized for COVID-19 balloon by 80 percent in just a day, from 3,805 on Wednesday to 6,844 patients on Thursday, according to the website The COVID Tracking Project, which gathers data from state health departments around the country. In total, the site tallied 10,465 patients hospitalized for the virus across 29 states and the island territory of Guam as of Friday afternoon.
APM Reports surveyed health departments in the remaining states to fill in some of the gaps.
In total, 39 states are currently tracking hospitalizations for COVID-19. Health Departments in Michigan and Washington, D.C., confirmed they are not. Officials in Washington state, California and Missouri say they are working on creating systems to collect the data, as several other states did in recent days, including Rhode Island, North Carolina and Vermont.
Health departments in Idaho, Kansas, Kentucky, Nebraska, Nevada and Wisconsin did not respond to repeated requests for data. A spokesman for the Illinois Department of Public Health told ProPublica that hospitalizations were "a very fluid situation," and it was unlikely that the state could collect the data daily.
California, which has the third highest number of confirmed COVID-19 cases in the country, typically collects hospitalization data for a range of illnesses every three months, according to the state Department of Health. The COVID Tracking Project lists 253 patients hospitalized in California, but the department says it has released no such data and the number is not accurate.
Washington state also faces challenges with data collection. It has compiled a weekly count of patients with COVID-like symptoms, but that data is messy and likely contains significant numbers of patients with other respiratory illnesses, said the Department of Health's Wickersham. The report may also double-count some cases, he said.
Wickersham's team is currently trying to create a more accurate real-time tally by linking two databases — one tracking positive COVID-19 tests and another tracking hospital admissions. It's a tool the department had long sought but that state leaders hadn't allocated money for, he said.
"Most of what we're doing right now is catchup work," Wickersham said. "It's work that we scoped years ago, that we never had the resources for, and we're having to do now, because the investment wasn't made at that time."