Compared to the general population, people who had been hospitalized for COVID-19—and survived for at least one week after discharge—were more than twice as likely to die or be readmitted to the hospital in the next several months, according to a study by University of Oxford researchers published in Plos Medicine.

Previous research has suggested that people with COVID-19 may face a greater risk of health issues for several months following their initial infection. However, evidence on this topic remains limited.

To help clarify long-term health risks for people with COVID-19, researchers focused on those who had been hospitalized for the disease. The researchers conducted a statistical analysis of electronic health records from the database OpenSAFELY, evaluating data on nearly 25,000 patients who had been discharged after being hospitalized for COVID-19 in 2020, and for comparison, more than 100,000 members of the general population.

The analysis showed that, compared to the general population, people who had been hospitalized for COVID-19 and lived for at least one week after discharge had twice the overall risk of hospital readmission or death in subsequent months. They also faced nearly five times the risk of death from any cause.

In order to account for risks after hospitalization for an infectious disease, the researchers also considered data from more than 15,000 people who had been hospitalized for influenza in 2017-19. Statistical analysis found that, compared to the influenza patients, COVID-19 patients faced a slightly lower combined risk of hospitalization or death overall. However, people who had been hospitalized for COVID-19 had a greater risk than influenza patients of death from any cause, a greater risk of hospital readmission or death resulting from their initial infection, and a greater risk of death due to dementia.

Overall, these findings align with other research showing increased risks of subsequent health issues for people who have had COVID-19. The authors suggest these risks could be mitigated by policies to increase monitoring of COVID-19 patients after discharge and to raise awareness of potential complications.

“Our findings suggest that people who have had a severe case of COVID-19 requiring a hospital stay are at substantially elevated risk of experiencing further health problems in the months after their hospitalization; it is important that patients and their doctors are aware of this so that any problems that develop can be treated as early as possible,” said Krishnan Bhaskaran from the London School of Hygiene and Tropical Medicine, University of Oxford. “Our findings also highlight the importance of getting vaccinated, which is the best tool we have for preventing severe COVID-19 in the first place.”