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.
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 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. 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. 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.
Metformin is a drug that many doctors prescribe as treatment for type 2 diabetes mellitus (T2DM). Studies in the past have found that taking metformin before and during a COVID-19 infection helps lower the chances of getting very sick with COVID. These studies also found that taking metformin can lower the chance of a person being sick many months after getting COVID, 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.
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 the infection. 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. 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.
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 a repeat COVID-19 infection, or reinfection, is worse than the first one. RECOVER researchers identified a reinfection when a person had a positive COVID-19 test at least 60 days after their first infection. 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.
Some people develop new conditions or symptoms after a COVID infection, 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. Researchers studied the electronic health records of 2.1 million people from New York and Florida who either had, or had not had, a COVID infection 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 a severe first COVID infection, 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 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 a COVID infection 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 while pregnant were less likely to get Long COVID than those who weren’t pregnant. Pregnant women with COVID 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 had a lower chance of getting Long COVID in the 30 to 180 days after they first got sick.
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 were infected with different variants of COVID. Researchers looked at medical records from 2 databases in New York and Florida. They compared people who had the original type of COVID 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 infected with Delta developed clots in the blood vessels in their lungs. People who had Delta were also more likely to have stomach symptoms than people who were infected with the original type of COVID. Based on these findings, the researchers concluded that Long COVID symptoms can be different depending on which variant of COVID someone had.
Doctors keep patient information in computer files called electronic health records (EHRs). RECOVER researchers can use these records to learn more about Long COVID, which is when someone feels sick for a long time after having COVID-19. But studying these records is not easy. It can be hard to get certain information from EHRs, when things that might explain why some people get Long COVID happen at different times. It can also be hard to put information from many hospitals together in one place and can cost a lot of money. In this study, RECOVER researchers made a new tool called ODACoR, which stands for “one-shot distributed algorithms for competing risks model.” This tool was used to look at the EHRs of 6.5 million kids and teens from 8 children’s hospitals. Researchers found that ODACoR was able to find information about things that could make children and teens more likely to get Long COVID. ODACoR could also combine information from different hospitals, which did not always work with old ways of studying health information. This tool gave the same results as if all the hospitals had shared all their information in one place, which is hard to do. This study is important because it can help doctors study other kinds of health problems using information from many hospitals.
This RECOVER study looked at why some people may have long lasting symptoms or new health problems after getting COVID-19. Researchers looked at the electronic health records of 3.7 million adults and children who were tested for COVID between March 2020 and May 2021. They compared the records of people who tested positive for COVID with people who did not.
The study found that both adults and children who were hospitalized with COVID were more likely to have at least 1 symptom in the months after getting COVID, like shortness of breath. They also found that adults who were hospitalized with COVID were more likely to have 3 or more symptoms, feel very tired, or develop a new health condition. Some of the conditions were diabetes, blood disorders, or diseases related to breathing. Even adults with COVID who were not hospitalized had a higher chance of certain symptoms or health issues compared to those who did not have COVID. This study is important because it shows that COVID can impact people’s health for a long time, even after their first infection is gone. These findings can help doctors and scientists better understand how to treat and care for people recovering from COVID.
