Discover what the latest science from the RECOVER Initiative means for our ability to understand, diagnose, prevent, and treat Long COVID.
This page contains descriptions of findings from RECOVER research studies. These descriptions use plain language and a format that is easy to understand.
If you want to learn more about the scientific discoveries described here, you can also browse and search the complete list of RECOVER Publications.
Metformin is a drug that many doctors prescribe as treatment for type 2 diabetes mellitus (T2DM). Past studies have found that taking metformin before and while having COVID-19 helps lower the chances of getting very sick with COVID-19. These studies also found that taking metformin can lower the chance of a person being sick many months after getting COVID-19, which is called Long COVID. In this study, RECOVER researchers were interested in understanding if people with diabetes who were on different medications got Long COVID or died. They looked at electronic health records (EHRs), or computer-based versions of patient health records, for 88,342 adults with T2DM. The study looked at 2 groups. The first group used metformin to control their diabetes, while the second group used other medications to control their diabetes. The researchers found that the chances of getting Long COVID or dying were a little bit lower in the group that took metformin compared to the group taking other medications. Since being on metformin may help only a little bit with Long COVID for adults with T2DM, people taking diabetes medications do not need to change their treatment plans unless told by their doctor.
In this RECOVER study, researchers wanted to find out which health conditions were common in people with long-term effects of COVID-19, known as Long COVID. They looked at the medical records of over 14 million patients who had and did not have COVID-19 using a method called topic modeling. Topic modeling is a method to find patterns in groups of documents. Researchers used topic modeling to look at lists of health problems that millions of patients faced over time, including before and after they had COVID-19. This allowed them to find the conditions that were more common in people with Long COVID. Researchers found that health problems related to the lungs, heart, brain, and immune system were more common in people with Long COVID compared to those who didn’t have Long COVID or had not had COVID-19. Common problems included chronic fatigue (feeling tired all the time), headaches, anxiety, and heart issues. They also found that some problems were more common in people of a certain age or sex (whether they are male or female). The study shows that Long COVID can affect many parts of the body and highlights how health problems can differ between groups. It also shows that age and sex can affect the chance of getting certain health conditions after COVID-19.
This RECOVER study looked at how a child or young adult’s body weight, measured by body mass index (BMI), might impact their risk of developing Long COVID. Researchers studied medical records from over 172,000 children and young adults across 26 hospitals between March 2020 and May 2023. They found that children and young adults with obesity (a high BMI) were 25% more likely to have long-term health problems after getting COVID-19 than those with a healthy weight. The findings also show that children with severe obesity (a very high BMI) were about 42% more likely to experience these long-term problems. They also checked if these links were different for children and young adults, but did not find significant differences. This study highlights that the BMI of children and young adults before getting COVID-19 is an important factor in their risk for developing Long COVID.
RECOVER researchers know that there is a lot of important information about COVID-19 and Long COVID in electronic health records (EHRs), especially in the notes that doctors write during care. The researchers used a computer tool called Natural Language Processing (NLP) to find signs and symptoms of different conditions. However, NLP doesn’t always work well, especially with new health problems like COVID-19 or Long COVID, which are always changing. To improve this, researchers created a new NLP system that could collect detailed information about Long COVID signs and symptoms from EHRs. After testing the system at other medical sites, they found it worked well across different locations. The study showed that the new NLP system could successfully find the information they were looking for about COVID-19 and Long COVID in EHRs. The NLP is now available to other researchers and is being used to collect information that can support additional studies on COVID-19 and Long COVID.
This RECOVER study looks at a medicine called nirmatrelvir/ritonavir, which is used to treat COVID-19 in teens and adults who are more likely to be hospitalized from COVID-19. Researchers wanted to understand why doctors might give this medicine to teens ages 12 to 17. They reviewed electronic health records (EHRs) from January 2022 to August 2023 to find which teens got this medicine after testing positive for COVID-19. Out of almost 21,000 teens with COVID-19, only 408 got the medicine within 5 days of diagnosis. The study found that teens with long-term health problems were 2.5 times more likely to get the medicine. Those with comorbidities (more than 1 ongoing health problem) were more likely to receive it. But most teens with 1 or more health problems did not receive this medication. This could be a reason why many teens with COVID-19 need to be hospitalized. The study also found that Hispanic or Latino kids were less likely to get the medicine compared to non-Hispanic, white kids. This study shows that kids with chronic health issues are more likely to get nirmatrelvir/ritonavir, but not many kids are getting this medicine overall.
Some people develop new conditions or symptoms after having COVID-19, called Long COVID. This can lead to ongoing health problems. Researchers still don’t fully understand why some people get Long COVID while others do not. In this RECOVER study, researchers wanted to learn what increases someone’s risk of developing Long COVID after getting COVID-19. Researchers studied the electronic health records of 2.1 million people from New York and Florida who either had or had not had COVID-19 between March 2020 and November 2021. Using this data, they created a new computational model (a computer program that imitates how something works in real life) to help identify the things that Long COVID patients had in common. The researchers looked at whether these shared factors increased their risk of developing Long COVID. The model found that the people who were more likely to develop Long COVID if they had severe COVID-19 the first time they got the virus, were underweight, or had other health problems, like cancer or liver disease. The results also show that computational models can help identify people who have a higher chance of developing different symptoms and types of Long COVID. This information is important because it can be used to help researchers find new ways to prevent, diagnose, and treat Long COVID.
Little is known about Long COVID in pregnant women. This study looked at whether getting COVID-19 while pregnant might increase the chances of getting Long COVID. Researchers from the RECOVER Patient-Centered Clinical Research Network (PCORnet) checked health records from 19 health systems across the US. They studied women ages 18–49 years old who had a test showing that they had COVID-19 between March 2020 and February 2022, and looked at 83,915 women who were not pregnant and 5,397 who were. Women who got COVID-19 while pregnant were less likely to get Long COVID than those who weren’t pregnant. Pregnant women with COVID-19 were more likely to develop certain conditions related to Long COVID, like an abnormal heartbeat. But they had a lower risk of getting other conditions, like malaise (feeling unwell). Overall, pregnant women with COVID-19 had a lower chance of getting Long COVID in the 30 to 180 days after they first got sick.
This RECOVER study looks at how often people get COVID-19 more than once and if they develop Long COVID afterward. The study also looks at whether getting COVID-19 multiple times, also called a reinfection, is worse than the first time getting COVID-19. RECOVER researchers identified a reinfection when a person had a positive COVID-19 test at least 60 days after getting COVID-19 for the first time. They studied the health records of over 3 million patients in different ways to understand COVID-19 reinfections. By studying a large number of patients, the researchers were able to learn key details about COVID-19 reinfections. They found that about 6.9% of people got COVID-19 more than once. Most reinfections happened when the Omicron variant was spreading. Researchers found that Long COVID was more common in people who had COVID-19 for the first time compared to those who were reinfected. This finding suggests that protecting yourself from getting COVID-19 is the best way to prevent Long COVID. People who had a moderate or severe case of COVID-19 the first time were also more likely to get very sick again when they were reinfected. These people were often older and at higher risk of death.
The virus that causes COVID-19 can change over time, creating new virus types called variants. This study explored if problems related to Long COVID were different in people who got different variants of COVID-19. Researchers looked at medical records from 2 databases in New York and Florida. They compared people who had the original type of COVID-19 with those who had a variant called Delta, which was one of the main variants in 2021. The researchers found that some Long COVID conditions were more common in the people who had Delta. For example, some people who got the Delta variant developed clots in the blood vessels in their lungs. People who had Delta were also more likely to have stomach symptoms than people who got the original type of COVID-19. Based on these findings, the researchers concluded that Long COVID symptoms can be different depending on which variant of COVID-19 someone had.
