RECOVER study examines how a person’s sex impacts Long COVID risk
Researchers found that women may have a higher risk for Long COVID compared to men—and that this risk varies based on age.
A RECOVER study recently published in JAMA Network Open reveals new information about how a person’s sex may impact their risk for developing Long COVID. This study is the largest study to date to examine the relationship between a person’s sex and Long COVID risk. It is also the first study to fully account for other known factors that could contribute to risk for developing Long COVID.
What did researchers do?
Researchers examined how often people developed Long COVID after having a SARS-CoV-2 infection, which is the virus that causes COVID-19. To conduct the study, researchers used data from 12,276 people (8,969 female participants and 3,307 male participants) enrolled in RECOVER’s adult observational study between October 29, 2021, and July 5, 2024. These participants also took part in a qualifying RECOVER study visit at least 6 months after their initial SARS-CoV-2 infection.
The study team wanted to know how a person’s sex (which they define in the study as self-reported biological sex assigned at birth) impacted their chance of developing Long COVID. To better understand the impact of a person’s sex on developing Long COVID, they also studied other known risk factors, including:
- A person’s age.
- Whether a female participant is still menstruating or has gone through menopause.
- A person’s other health conditions.
- A person’s COVID-19 vaccination status.
- Which COVID-19 variant a person was infected with.
- Severity of a person’s SARS-CoV-2 infection.
- Whether a person was hospitalized during their SARS-CoV-2 infection.
To determine which participants in the study had Long COVID, researchers used a Long COVID research index (or scoring system) based on the most-reported Long COVID symptoms. This index was previously developed by RECOVER researchers using data from the adult observational study and was updated in late 2024.
What did researchers find?
Researchers found that women were more likely to develop Long COVID than men. More than 20 of every 100 (20.6%) female participants included in the study had Long COVID, compared to about 16 of every 100 (16.01%) male participants studied. Even when considering other known Long COVID risk factors, women’s risk for developing Long COVID remained 31% higher than men’s risk.
However, when researchers grouped study participants by age, they found differences, including:
- Women between 40 and 54 years old had the highest risk for developing Long COVID. Women in this age group who had not gone through menopause were at a 45% higher risk than men in the same age group. Menopause was found to decrease this risk slightly, as women who had gone through menopause between the ages of 40 and 54 experienced a 42% higher risk than men for developing Long COVID.
- For women between the ages of 18 and 39, sex did not present a significantly higher risk of developing Long COVID compared to men in the same age group. Researchers noted that most pregnant women are in this age category and that hormone changes during pregnancy may reduce the risk of getting COVID-19 or help with recovery from COVID-19.
Why are these findings important?
This study adds valuable context around how much a person’s sex increases the risk of developing Long COVID. Previous studies did not fully account for other COVID-19 risk factors that could distort the true impact of biological sex.
The RECOVER adult observational study cohort (or group of participants included in the study) is larger and more comprehensive than groups included in some research studies. This means that the study includes people from different backgrounds and all walks of life. Previous studies had relatively small study populations (small groups of people included in the study) or populations that were not as comprehensive, meaning that researchers could not draw conclusions from their results to represent what might be seen in a wider population.
Better understanding of sex-specific Long COVID risk can help identify which patients may develop Long COVID, develop potential treatments that are tailored for specific populations, and improve care for people living with Long COVID.
Read the full publication in JAMA Network Open.