From SciTechDaily, "
New Research Helps Explain Dramatic Declines in COVID-19 Death Rates" by NYU Langone Health / NYU School Of Medicine, October 22, 2020:
After New York became the epicenter for the pandemic in early March, with tens of thousands dying from COVID-19, experts had expected that the infection would remain as deadly in the following months.
Instead, a new investigation showed that by mid-August the death rate in those hospitalized with coronavirus-related illness had dropped from 27 percentage points to about 3 percentage points. Led by researchers at NYU Grossman School of Medicine, the study showed that a younger, healthier group of people were getting infected and were arriving at the hospital with less-severe symptoms than those infected in the spring.
However, the researchers’ analysis showed that these factors accounted for only part of the improvement in survival. The rest, they suspect, resulted from health care providers’ growing experience with the coronavirus. For example, physicians learned that resting COVID-19 patients on their stomachs rather than their backs and delaying the use of ventilators as long as possible were more effective practices, say the study authors. Drugs likely helped as well. In addition, other factors such as decreasing hospital volumes, less exposure to infection, and earlier testing and treatment, may have played a role. [Emphais added.]
***[Leora] Horwitz [MD, an associate professor in the Department of Population Health at NYU Langone Health] says the new study, publishing online next week in the Journal of Hospital Medicine, is the most detailed analysis to date of coronavirus death rates over time. By accounting for age, obesity, and other key factors, the researchers were able to eliminate some explanations from the analysis.