Can long Covid lead to death? A new analysis suggests it could

The Centers for Disease Control and Prevention is analyzing more than 100 deaths that could be attributed to long Covid by looking at death certificates from across the country over the last two years, according to two people familiar with the matter.

The National Center for Health Statistics, a division within the CDC, collects death certificates from states after they have been completed by a coroner, medical examiner or doctor. NCHS is now reviewing a batch of those files from 2020 and 2021.

The review at the CDC, the details of which POLITICO obtained, is the first of its kind and indicates that long Covid and the health complications associated with it could lead to death. NCHS is set to publish preliminary data from its analysis in the coming days.

It's unclear whether the people who died had underlying health issues, whether long Covid was the cause of their deaths or whether it was a contributing factor.

The new data comes as state and federal health officials work to understand the significance and severity of long Covid, which may affect as many as 30 percent of people who contract the virus, according to studies published in the Journal of the American Medical Association. Two years into the pandemic, relatively little is known about long Covid’s prevalence, how to diagnose it or the best practices for treatment.

“The overall risk factors for mortality with long COVID are going to be important and evolving,” said Mady Hornig, a physician-scientist at the Columbia University Mailman School of Public Health who is researching long Covid. The CDC is still collecting and revising data, but NCHS has so far identified 60 death certificates that list long Covid or similar terminology — for example, “post-Covid” — in 2021 and another 60 during the first five months of 2022.

A spokesperson for the CDC said the agency is “working on identifying any deaths attributed to … long Covid-19” and plans to publish the numbers “soon.”

There is no test for long Covid, and the CDC and the medical community have no official definition. But health care workers across the country are diagnosing patients who have previously contracted Covid-19 based on a wide-ranging set of symptoms that often include fatigue, shortness of breath and brain fog. Researchers and scientists have said that between 10 and 30 percent of people who have survived a Covid-19 infection will develop long Covid. A CDC study released May 27 said one in five adults in the U.S. may develop the condition.

Still, it's difficult to determine exactly how many people in the country have long Covid. The condition is not easy to diagnose, especially without a universal definition. Long Covid can impact multiple organ systems and what may be a long Covid symptom for one patient may not be for another.

The muddied diagnosis process has made it harder for researchers to study long Covid. Dozens of hospitals and medical clinics are accepting patients with long Covid symptoms for treatment and trying to use that data to better understand the condition and why it manifests itself in some who have previously contracted the virus but not others. The National Institutes of Health is overseeing the largest national study of long Covid.

In October 2021, after CDC approval, hospitals and medical facilities in the U.S. began tracking patients exhibiting long Covid symptoms with a specific identification known as an ICD-10 code. That coding system, used for most reportable illnesses, has helped researchers narrow which group of people to study.

However, in almost all instances, long Covid sample populations are limited, constraining researchers' ability to understand how the condition impacts different people.

“There is a significant underdetection of long Covid,” said Sairam Parthasarathy, chief of the pulmonary division at the University of Arizona’s medical school and one of the leads on its long Covid study. “It ties into health literacy … of someone being aware that they have a medical problem. If someone feels that they don't have a medical problem, sometimes they may not seek care.”

Socioeconomic factors also come into play, Parthasarathy said, including whether someone has the resources and time to go to the doctor.

There is no set wording or terminology that hospitals use on death certificates — the CDC has yet to issue guidance. So, no official estimates exist for long Covid deaths.

Very few studies have examined the relationship between long Covid and mortality. But one November 2021 study of European cancer patients, published in The Lancet, showed a relationship between long Covid and morbidity of the sample population. The study found that about 15 percent of those who survived Covid-19 had long Covid symptoms and their survival outcomes were significantly worse. It also found that those individuals were more likely to discontinue systemic anti-cancer therapy permanently.

“It certainly is possible and probable that someone who was sick from Covid develop complications after Covid and die of long Covid,” said Jerry Krishnan, a pulmonary physician at the University of Illinois Chicago who is leading the institution’s long Covid clinical study. “I have not seen the data. But I have heard that people have developed heart or lung or brain complications after having had Covid. And eventually they have died.”

The CDC analysis is pulling death certificates that have words like “long Covid” or “post Covid,” which could indicate that someone has died as a result of the condition. NCHS conducted a similar review of death certificates when the Covid-19 pandemic began in 2020. The CDC eventually issued a notice for health care providers to use a specific code for deaths that could be attributed to Covid-19. It allowed federal and local researchers to study how and whether the virus caused severe disease in some groups more than others.

Although there's no death certificate code for long Covid, Parthasarathy said it is possible to rely on what the medical community already knows about how severe disease from Covid-19 affects different populations to get a sense of long Covid's effects on those same groups of people.

“We know that people of color were disproportionately affected by Covid disease as opposed to just mild SARS-CoV-2 infection. And we know that people who are hospitalized with Covid are more likely to have long Covid,” he said, adding that he recently sat in on a presentation with NCHS that indicated people of color had a higher prevalence of long Covid. “When they showed those numbers … it was like, ‘of course.’ We were able to connect the dots.”