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Mass. General models show flattening curve; COVID-19 patients not expected to overwhelm the system during this week’s surge

Expect hospital admissions for coronavirus may begin to lower in about a week

Mass. General analysts say they believe that the crush of very sick patients at its doors is unlikely to get worse — and could start to ease in a week.Jessica Rinaldi/Globe Staff/file

Doctors and mathematicians at Massachusetts General Hospital, part of a little-known modeling team, are now optimistic that the number of coronavirus patients has plateaued at their institution, as well as in their larger hospital network, and will not overwhelm clinicians.

The Mass. General predictions come at a time when the state is considered a national hotspot for COVID-19 and when data show 100 to 150 Massachusetts residents dying daily from the virus. But analysts at the hospital believe that the crush of very sick patients at its doors is unlikely to get worse — and could start to ease in a week.


“A lot of people still believe we are in a worst-case scenario, and that’s actually not true,” said Dr. Peter Dunn, a vice president overseeing inpatient capacity management at Mass. General. “The curve is flattening even more and it is due to all the many community- and government-based efforts to minimize the spread.”

Dunn also cited “the preparation we were able to put into place across all of the health care systems throughout Greater Boston.”

Dunn warned, as others have, that hospital leaders — and the public — cannot let down their guard. But he said Mass. General started growing confident in the second half of March that the hospital and others in Eastern Massachusetts would be able to handle the surge of very sick patients. Though there have been spikes and anxieties, including a rapid rise of infected residents in Chelsea most recently, the team’s predictions have largely panned out.

"That does not mean we are not in a really challenging scenario right now,'' Dunn said. "It may not be the extreme but it’s far more than any of our health systems were built for.''

When Mass. General officials started to prepare fully for the coronavirus outbreak in March, one scenario alarmed them. Doctors and mathematicians plugged such information as infection rates into a special calculator which predicted that, at worst, more than 1,000 COVID-19 patients could require hospital care in Mass General at once. The hospital has about 1,000 beds, but that projection did not include patients needing to be hospitalized with other illnesses.


Mass. General, like other hospitals, sprang into action and canceled hundreds of non-urgent elective surgeries and converted regular floors into extra intensive care units.

The modeling team’s recent projections predict the hospital will have about 376 COVID-19 patients in the hospital each day, at least through the coming weekend, including 170 patients in its ICUs, according to the latest data shared with the Globe. If the situation somehow worsens quickly, the hospital could set up 370 ICU beds if necessary.

The team also analyzed its entire network, Partners HealthCare, which consists of nine acute care hospitals, including Brigham and Women’s Hospital, Newton-Wellesley Hospital, and North Shore Medical Center. It predicts that patient admissions in those hospitals has also plateaued, with about 866 COVID-19 patients across the Partners network hospitalized each day.

The team does not make statewide predictions, but given Partners’ broad reach in Eastern Massachusetts, its experience is an important window into the region overall. Governor Charlie Baker echoed this optimism Monday, during an interview with Boston 25 News, indicating that even as more residents are diagnosed with coronavirus, there should be little fear that sick patients with COVID-19 will create unbearable strain on medical providers and require rationing of resources such as ventilators.


The state reported Monday that the death toll from the coronavirus outbreak in Massachusetts had risen by 103 cases to 1,809. The number of confirmed coronavirus cases climbed by 1,566 to 39,643.

Dunn said Monday that his team’s projections held up last week and over the weekend, even after infections among residents mounted in nearby Chelsea. The virus has taken a strong hold in that densely-packed city — on just one day last week, as part of Mass. General’s expanded testing in the city, about half of 178 people tested were positive for coronavirus.

Dr. Joseph Betancourt, vice president and chief equity and inclusion officer, said Monday that hospital admissions from Chelsea seem to have flattened over the previous five days. "I definitely feel like we have all the trains on the tracks and we are seeing some results,'' he wrote in an e-mail.

The Mass. General health care systems engineering team began in 2007 with a far humbler project: determining how many elevators would be needed to transport surgery patients during a hospital construction project. The group said two elevators would be more than enough, which was met with some disbelief but turned out to be correct. The team earned credibility for bigger projects.

In March, after the coronavirus pandemic exploded in China, the group began with a Weill Cornell Medical College COVID-19 case calculator, which estimates a hospital’s caseload using a range of factors including its typical patient load in the region, infection rate, and hospitalization rate. But because many of these factors were uncertain, the calculator spit out best-case and worst-case predictions. Mass. General — and all the Partners hospitals — began drawing up plans to try to accommodate the heaviest possible caseload.


"We did not know where we were going to be between the two,'' Dunn said.

The modeling group turned to data from Italy to map out how fast the number of patients hospitalized with coronavirus was increasing. Very soon, as the hospital gathered its own real-time data, it could see that Mass. General’s curve was below the hard-hit Italian region of Lombardy.

At the same time, an influential modeling group at the University of Washington, the Institute for Health Metrics and Evaluation, was making its own predictions for Massachusetts and the country, which have fluctuated wildly. A week ago, it estimated a staggering 8,219 COVID-19 deaths in Massachusetts, nearly twice the state’s forecasts, saying its dire predictions were partly because the state had issued a stay-at-home “advisory” rather than an "order.'' It has since lowered its projections for Massachusetts on Monday to about 3,200 deaths by Aug. 4, citing a new way of determining how much a community is following social-distancing messaging.

Dunn and his team said these types of predictive models had often failed to account for local variation, such as how well residents keep their distance from one another, regardless of what the guidance is called. The Mass. General team does not forecast the number of deaths from the virus.


Still, there have been bumps in the road, as Mass. General experienced last week.

Amid growing numbers of very ill patients, many from Chelsea, arriving at the emergency department and requiring hospitalization, Mass. General stopped accepting transfers from other hospitals for 48 hours last week. The hospital still had 20 ICU beds available, Dunn said, but leaders like to stay ahead by much more than that.

So the decision was made to have Brigham and Women’s Hospital, the other large academic medical center in Partners, take transfers from smaller hospitals during that period until Mass. General could build its capacity.

"We hated doing it,'' said Ann Prestipino, a senior vice president and incident commander, during a Zoom meeting last Wednesday with hospital leaders. "We were concerned about the number of COVID patients and we needed to preserve some capacity.''

Dr. Kyan Safavi, a member of the modeling team, explained there were now more than enough ICU beds.

Dunn said the big question now is how long the plateau will last and when numbers of hospitalized patients will start to fall, a question his team has not answered yet. But, he said, that could start to happen next week.

"That will be the next piece of work,'' he said. "We still need to maintain same level of preparedness day to day to make sure things aren’t changing.''

Liz Kowalczyk can be reached at