'Long haulers' study suggests even mild COVID-19 could increase risk of death up to 6 months after infection

• Mild COVID-19 increased risk of death by about 60% in a new study.
• The study found a higher risk of death in the months after infection, even in those not hospitalized with COVID-19.
• The study included mostly white males with an average age of 66.

Mild COVID-19 made people more likely to die for six months in a large-scale study published Thursday in Nature.

The study, of nearly 73,000 mostly male veterans, found that people who had COVID-19 but weren't hospitalized were 59% more likely to die more than a month after diagnosis, compared to someone without the virus.

A higher risk of death extended to at least six months. The study's authors, from the US department of Veterans Affairs, estimated that mild COVID-19 would cause eight more deaths per 1,000 people six months out from diagnosis, compared to an average group of people on the US department of Veterans Affairs database.

The numbers were higher for those who had hospital treatment - a separate group of nearly 14,000 people in the study. The authors estimated that out of 1,000 people who received hospital treatment for COVID-19, 28 more would die within six months of diagnosis, compared with an average group of 1,000 on the database.

Due to the nature of the study, it was not possible to say whether COVID-19 caused these deaths. The cohort for mild COVID-19 comprised more than 73,000 mostly white (76%), male (90%) war veterans with an average age of 66, so it is not clear whether the findings apply to a wider population.

The US department of Veteran Affairs researchers also found that those not needing hospital treatment required 20% more ongoing care than someone who hadn't gotten infected. Some of these people had lingering symptoms, including respiratory symptoms, headaches, mental-health conditions, and metabolic disorders.

A previous study from France, reported on by Insider's Aria Bendix in March, found that 40-year-old women were most at risk of so-called "long-COVID," - a range of symptoms lasting a month or more after first catching coronavirus or that appear weeks after infection.

The authors of the new study didn't provide much detail about the symptoms, including how long they lasted for, and whether the veterans had preexisting conditions before they caught COVID-19.

The authors also reported increased use of certain medications, including pain medication, cough medicines, inhalers, and mental health treatments in those who had COVID-19, but didn't give much detail.

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"If there ever was an exemplar in clinical medicine that best illustrates the importance of integrated multidisciplinary care, it is #longcovid," Ziyad Al-Aly, the chief of research and education service at Veterans Affairs, and one of the study authors, said on Twitter Thursday.

"Health systems should quickly adapt to this reality," he said.

Dr. Laurie Jacobs, chairwoman of internal medicine at Hackensack University Medical Center, who was not involved in the study, told the New York Times that her experience reflected the findings of the study.

"People have continued respiratory disease, continued headache, this, that and the next thing," she said.

"It's not gone away. And we don't yet understand the underlying cause, and it's become chronic in some cases, disabling in other cases. In some areas, people have gotten better, but it's very variable."