Studies Show Significant Drop in Mortality Rate Since Beginning of Pandemic

Ambulances line up outside Maimonides Medical Center, as the spread of the CCP virus continues, in the Borough Park area of Brooklyn, N.Y., on Sept. 25, 2020. Brendan McDermid/Reuters

Two recent studies found that the rate of mortality has been dropping for hospitalized COVID-19 patients.

One of the studies was conducted on hospitalizations in the New York University Langone Health system between March and August. An author of the study, Leora Horwitz, also an associate professor at the Grossman School of Medicine at NYU, said that from the beginning of the pandemic until now, the mortality rate for patients infected with the CCP (Chinese Communist Party) virus has decreased significantly.

The study, which looked at over 5,000 patients inside the Langone Health system, discovered that in the study timeframe, the mortality rate decreased from 25.6 percent in March to 7.6 percent in August—an 18 percentage point decrease from the start of the pandemic.

According to the data, the median age was seen to have decreased over time, meaning that as time went on, most patients infected with the CCP virus were younger. Although that change seemed to partially explain the decreased mortality rate, it didn’t account for all of it.

“Even after risk adjustment for variety of clinical and demographic factors, including severity of illness at presentation, mortality was significantly and progressively lower over the course of the study period,” the study stated.

Patients of all ages experienced a decreased mortality rate. Among those, patients who were at or over the age of 75 saw the largest decrease, from just under 45 percent in the beginning of March to a under 10 percent in August.

A drive-thru Coronavirus COVID-19 testing station at a Kaiser Permanente facility in San Francisco, Calif., on March 12, 2020 Justin Sullivan/Getty Images

The study also suggests that the decreased mortality may be in part due to a combination of factors such as increased clinical experience, decreased hospital volume, as well as more advanced treatment procedures, something that was seen in another study conducted in the United Kingdom.

Similarly, a second study (pdf) also conducted in the Alan Turing Institute in the United Kingdom, discovered similar results, whereby there was a sharp decrease in mortality rates over the course of the study period, which was between March 1 and May 30.

“There has been a substantial mortality improvement in people admitted to critical care with COVID-19 in England, with markedly lower mortality in people admitted in mid-April and May compared to earlier in the pandemic,” the study read.

As with Horwitz’s study, even after the adjustment made for the patient demographics, the decrease in mortality persisted, meaning that the demographic change isn’t likely the main cause of the mortality rate decrease.

“Possible causes include the introduction of effective treatments as part of clinical trials and a falling critical care burden,” the study read.

Bilal Mateen, one of the authors of the second England study conducted at the Alan Turing Institute, called it a silver lining, according to WBUR.

“I would classify this as a silver lining to what has been quite a hard time for many people. Clearly, there’s been something [that’s] gone on that’s improved the risk of individuals who go into these settings with COVID-19,” Mateen said.