Researchers Detail Challenges of Determining Coronavirus Mortality

By Christopher Cheney

The number of deaths directly and indirectly associated with the coronavirus disease 2019 (COVID-19) pandemic is probably higher than has been reported, a new journal article says.

The United States has had the highest number of reported COVID-19 cases and deaths. As of Sept. 18, there were more than 6.8 million COVID-19 cases and more than 202,000 deaths reported in the United States, according to worldometer.

The co-authors of the new journal article, which was published in Annals of Internal Medicine, wrote that it is essential to have an accurate count of COVID-19 deaths. “Estimates of direct, indirect, and excess deaths are critical to our understanding of the pandemic and its effect on human life. They also illuminate the weaknesses in our health system and societal structures. It is imperative to get them right.”

The journal article focuses on three challenges to determining COVID-19 mortality and offers solutions for each.

1. Direct deaths

For a death to be directly associated with a disaster, the cause of death must be listed on the deceased person’s death certificate. However, the new journal article points out that the Council of State and Territorial Epidemiologists did not set a case definition for COVID-19 until April 5, which was nearly three months after the first reported coronavirus case in the United States.

“Early in the pandemic, when the understanding of the clinical presentation of COVID-19 was still developing and testing rates were very low, it is likely that practitioners in the United States and elsewhere did not attribute all deaths in patients infected with SARS-CoV-2 to COVID-19,” the journal article’s co-authors wrote.

The Centers for Disease Control and Prevention (CDC) took action to avoid under-counting COVID-19 deaths, the journal article’s co-authors wrote. “To account for possible underestimation from underdiagnosis of deaths attributable to COVID-19, the CDC began counting all deaths from pneumonia, influenza-like illness, and COVID-19 and subtracting the expected seasonal number of cases of pneumonia and influenza computed from trends in the previous 5 years.”

To achieve a more accurate count of deaths directly associated with COVID-19, the journal article calls for stepping up efforts to educate physicians about CDC guidelines—particularly for documenting presumed cases.

2. Indirect deaths

There are several forms of indirect causes of death associated with COVID-19, including psychological distress prompting suicides, the journal article’s co-authors wrote.

“In the context of the COVID-19 pandemic, this would include loss of wages or housing, disruption to medical care from temporary suspension of outpatient facilities, hospital or emergency department avoidance, postponement of surgeries or chemotherapy, and loss of health insurance, all of which could result in premature deaths,” they wrote.

There are three challenges in accounting for indirect deaths associated with COVID-19, according to the journal article.

  • The complexity of the intersection between economic and social disruptions
  • Lack of consensus about the timescale for measuring deaths after a disaster
  • Interpreting the CDC’s “but for” principle, which in this instance holds that “but for the [pandemic], would the person have died when he/she did?”

To account for indirect deaths associated with COVID-19, the journal article calls for improving death certificate reporting at the institutional, city, and state levels. “Applying the CDC’s ‘but for’ test to include ‘COVID-19’ in part II or question 43 [of death certificates] is therefore a simple and feasible intervention that may greatly improve the reporting of indirect death,” the journal article’s co-authors wrote.

They also call for physicians to receive “refresher training” on how to fill out death certificates.

3. Excess deaths

In addition to accounting for direct and indirect deaths associated with a disaster such as the coronavirus pandemic, disaster mortality can estimated by comparing observed deaths with the expected mortality rate based on the experience in prior years, the journal article says.

Calculating excess deaths is an imprecise science and should be set in a range, the co-authors wrote. “The estimation of excess mortality requires both modeling and timely data from reliable civil registries and vital statistics records, and it may be associated with significant margins of uncertainty.”

To rise to this challenge, timely access to baseline and mortality-range data is essential, the co-authors wrote. “These data would ideally be available in near real time from the states before being sent to the CDC or Department of Health and Human Services for further coding or analysis, allowing scientists prompt access to the most up-to-date information from each state.”

Accounting for COVID-19 deaths

At this point in the coronavirus pandemic, it is difficult to determine the extent of the understatement of COVID-19 deaths, a co-author of the journal article told HealthLeaders.

“Given the pandemic is still raging across the United States, testing continues to vary widely, and because the impact of indirect deaths will not be immediately obvious, it is not yet possible to estimate how high the true mortality will be,” said Satchit Balsari, MD, MPH, an assistant professor of emergency medicine at Harvard Medical School and Beth Israel Lahey Health in Boston.

Balsari discounted media reports that have claimed the number of COVID-19 deaths have been overestimated.

“The reports make this claim on the basis that some deaths may be wrongly attributed to COVID-19 when the patient died of something else just because they also had COVID-19. There is no evidence so far that the number of such cases is statistically significant. In fact, there are peer-reviewed research articles that demonstrate how mortality rates reported early in the pandemic are lower from a combination of decreased testing, evolving understanding of the disease (missed diagnoses), and sometimes simply delays in reporting,” he said.

Christopher Cheney is the senior clinical care​ editor at HealthLeaders.