Large population study identifies long-term health risks after COVID-19 hospitalization

A nationwide study has revealed that survivors of COVID-19 hospitalization face an increased risk of death or organ-related disorders for up to two-and-a-half years after discharge.

Published today in Infectious Diseases, the study of nearly 64,000 French residents provides valuable insights into the long-term health effects of COVID-19 and emphasises the need for continued healthcare and monitoring for people who have been hospitalised with SARS-CoV-2 infection.

“These findings are a stark reminder of the far-reaching impact of COVID-19, which extends far beyond the initial infection,” says lead author Dr Sarah Tubiana, who specializes in infectious diseases, at the Clinical Investigation Center at Bichat Hospital (Paris).

“While much attention has been given to the immediate dangers of the virus,” Dr Tubiana adds, “our research shows that hospitalised COVID-19 survivors remain at greater risks of severe health complications months and even years later. The long-term implications for public health are significant.”

Using data from the French national claims database, the study followed 63,990 adults admitted to hospital with COVID-19 between January and August 2020. These individuals – with an average age of 65 years, with 53.1% male – were matched with 319,891 people from the general population of similar age, sex and location who had not been hospitalised for COVID-19 during the same period.

The researchers tracked the study participants for up to 30 months, monitoring deaths and hospital admissions, both for any cause and for specific organ-related conditions. By comparing outcomes between the two groups, the researchers identified significant long-term health risks in hospitalised COVID-19 survivors than the general population.

COVID-19 patients experienced a higher rate of deaths from any cause (5,218 per 100,000 person-years) compared to the control group (4,013 per 100,000 person-years). They were also more likely to be hospitalised for any reason, with particularly high risks for neurological, psychiatric, cardiovascular and respiratory problems.

There was no difference between men and women in the risk of hospitalization except for psychiatric, for which the excess risk was mainly found in women.

The odds of re-hospitalization – following discharge of a COVID-19 hospitalization – was higher for all age groups.

However, as perhaps expected, the incidence of all-cause re-hospitalization and re-hospitalization for organ specific disorder were higher in patients older than 70.

While these excess risks decreased after the first six months for all outcomes, they remained elevated for up to 30 months for neurological and respiratory disorders, chronic kidney failure and diabetes.

“Even 30 months after hospitalisation, COVID-19 patients remained at an increased risk of death or severe health complications, reflecting the long-lasting, wider consequences of the disease on people’s lives,” states co-author Dr Charles Burdet, an Infectious Diseases specialist, at Université Paris Cité.

“These results highlight the need for further research to understand the mechanisms behind these long-term health risks and how to mitigate them.”

A key strength of this study is its use of a large, nationwide database covering the entire French population, making the findings broadly applicable to similar Western populations. Using longitudinal data and detailed electronic health records also allowed the researchers to distinguish new health issues arising after COVID-19 from pre-existing conditions.

However, the findings may not fully apply to later SARS-CoV-2 variants, as the study focused on patients infected in early 2020 before new variants emerged. Further research is needed to assess whether more recent variants have similar long-term health consequences.

Reference:

Tubiana, S., Rontani, M., Herlemont, P., Dray-Spira, R., Zureik, M., Weill, A., … Burdet, C. (2025). Long-term health outcomes following hospitalisation for COVID-19: a 30- month cohort analysis. Infectious Diseases, 1–11. https://doi.org/10.1080/23744235.2025.2452862