CHICAGO — Researchers at Washington University School of Medicine in St. Louis showed that COVID-19 survivors, including those not sick enough to be hospitalized, have an increased risk of death in the six months following diagnosis with the virus.
The researchers analyzed data from the national health-care databases of the U.S. Department of Veterans Affairs. The dataset included 73,435 Veterans Health Administration (VHA) patients with confirmed COVID-19 but who were not hospitalized and, for comparison, almost 5 million VHA patients who did not have a COVID-19 diagnosis and were not hospitalized during this time frame. The veterans in the study were primarily men, almost 88 percent, but the study still included 8,880 women with confirmed cases.
The study showed that, after surviving the initial infection, usually beyond the first 30 days of illness, COVID-19 survivors had an almost 60 percent increased risk of death over the following six months compared with the general population. At the six-month mark, excess deaths among all COVID-19 survivors were estimated at eight people per 1,000 patients. Among patients who were ill enough to be hospitalized with COVID-19 and who survived beyond the first 30 days of illness, there were 29 excess deaths per 1,000 patients over the following six months.
Among hospitalized patients, those who had COVID-19 fared considerably worse than those who had influenza, according to the analysis. COVID-19 survivors had a 50 percent increased risk of death compared with flu survivors, with about 29 excess deaths per 1,000 patients at six months. Survivors of COVID-19 also had a substantially higher risk of long-term medical problems.
The researchers also found that the health risks from surviving COVID-19 increased with the severity of disease, with hospitalized patients who required intensive care being at highest risk of long COVID-19 complications and death.
To understand the long-term effects of more severe COVID-19, the researchers harnessed VHA data to conduct a separate analysis of 13,654 patients hospitalized with COVID-19 compared with 13,997 patients hospitalized with seasonal flu. All patients survived at least 30 days after hospital admission, and the analysis included six months of follow-up data.
The researchers confirmed that, despite being initially a respiratory virus, long COVID-19 can affect nearly every organ system in the body.
In future analyses of these same datasets, the researchers plan to look at whether patients fared differently based on age, race and gender to gain a deeper understanding of the risk of death in people with long COVID-19.
The study was published Thursday online in the journal Nature.