Mortality: Learning from COVID-19 Waves

March 23, 2021

Saskia v. Popescu, PhD, MPH, MA, CIC, is a hospital epidemiologist and infection preventionist. During her work as an infection preventionist, she performed surveillance for infectious diseases, preparedness, and Ebola-response practices. She holds a doctorate in Biodefense from George Mason University where her research focuses on the role of infection prevention in facilitating global health security efforts. She is certified in Infection Control and has worked in both pediatric and adult acute care facilities.

The challenges of explaining new guidance, like that for school-aged children, is so important to ensure people understand the science and reasoning behind it, but also why following it is important.

We are at a particularly challenging and nuanced time in the SARS-CoV-2/COVID-19 pandemic. The presence of multiple efficacious vaccines across many countries means that millions are being vaccinated, but we’re also struggling to ensure vaccine access and equity, racing against variants and increasing re-openings, and concerns that we may yet see another surge.

The challenges of explaining new guidance, like that for school-aged children, is so important to ensure people understand the science and reasoning behind it, but also why following it is important. The concerning piece though, is that many countries are seeing worrisome trends of rising cases.

In Europe, France is implementing new lockdowns in various areas, Italy reinforced a shutdown over Easter, and the Czech Republic is issuing harder closures and lockdowns. In the United States, the decline in cases has slowed and appears stagnant, with daily cases holding around 54,000. In the United States alone, nearly 540,000 lives have been lost—a number that is a painful reminder of our failures and the challenges of treating patients with a novel respiratory infection.

In terms of mortality, are we making progress are reducing it? A new research study addresses morality rates between waves of COVID-19 in Europe and the United States to analyze if there has progression in reducing COVID-19 mortality. Realistically, the hope is that as time progresses, we get better at treating patients and ultimately reduce the risk of death.

The authors note that “identifies similarities in the trajectories of cases and deaths for European countries and US states. Our analysis refines the popular conception that the mortality rate has greatly decreased throughout Europe during its second wave of COVID-19; instead, we demonstrate substantial heterogeneity throughout Europe and the U.S.”

By analyzing the first and second waves through a mathematical framework to assess changing mortality relative to each wave, the researchers looked at country-by-country levels and then compared them, as well as states within the United States, totally 93 countries and states.

The researchers ultimately found that the Netherlands had the largest reduction in mortality. Followed by Denmark, France, and Belgium, they found that Western European countries had a greater reduction in COVID-19 mortality than Eastern European countries and those American states.

The authors note that “We have shown significant variance in the mortality ratios, with European countries spanning a wide spectrum. For example, the Netherlands has reduced its mortality drastically, Germany has done so moderately, while Belarus’ mortality has slightly increased. Wealthy Western and Northern European countries, with the notable exceptions of Germany and Sweden, have reduced their mortality more than all US states and the rest of Europe.”

Overall, the research team noted that there are several factors that can impact these changes in mortality—various levels of waves, the demographics of those impacted, access to healthcare and systems, etc. What was particularly interesting was that for those countries/states that had a severe first wave, were able to reduce their mortality following it—these were predominantly wealthier countries and states. Fundamentally, this underscores the importance of rapid development of therapeutics and ultimately, care for emerging infectious diseases, but also addressing social and racial inequalities that can reduce quality and access to care.