Three years after intensive care: lasting effects of severe COVID-19

The research includes 498 patients with COVID-19 who received intensive care in Skåne during the first year of the pandemic, of whom 303 survived the...

Recovery among patients who were critically ill with COVID-19 slowed markedly after the first year, both physically and psychologically. This is demonstrated in a new three-year follow-up study conducted by Skåne University Hospital and Lund University. The research includes 498 patients with COVID-19 who received intensive care in Skåne during the first year of the pandemic, of whom 303 survived the acute phase.

According to lead researcher Ingrid Didriksson, Consultant at Skåne University Hospital and Doctor of Medicine at Lund University, many patients continue to experience ongoing health problems.

“Many still live with substantial health issues three years after intensive care. A large proportion do not regain the functional level they had before falling ill,” she says.

Recovery plateaued after one year

Physical recovery improved steadily during the first year, with the proportion of patients achieving good functional recovery rising from 35 to 64 per cent. After this point, progress plateaued. Three years after intensive care, 64 per cent continued to report dyspnoea, while 41 per cent experienced pronounced fatigue.

One possible explanation is prolonged activation of parts of the immune system after the acute infection, which could contribute to long-lasting symptoms. However, more research is needed to confirm this, emphasises Ingrid Didriksson.

Mental health worsened between one and three years

Mental health followed a different trajectory. Three months after discharge, many patients felt better than expected, possibly due to the relief of having survived.

However, from one to three years after intensive care, a clear deterioration was observed. An increasing number of patients reported symptoms of anxiety and depression.

“The group reporting the poorest mental health were individuals aged 50–60. Many in this age group are expected to return to work and everyday routines, but persistent physical limitations make this difficult. That may contribute to poorer mental wellbeing,” says Ingrid Didriksson.

Patients with overweight or obesity were over-represented among those who required intensive care, which aligns with national and international evidence from the pandemic. However, their survival during the acute phase was comparable to that of other patient groups.

“It is important to highlight that although overweight increased the risk of needing intensive care, we did not see a higher mortality rate among these patients once they were admitted to ICU,” says Ingrid Didriksson.

Intensive care strain affected survival

Mortality was highest during periods when intensive care units were under the greatest pressure, even after adjusting for patient severity. According to Ingrid Didriksson, this underscores the need to be able to rapidly expand intensive care capacity during future crises.

“We cannot afford to be unprepared. New pandemics or other healthcare emergencies will occur, and we must have robust structures in place to increase capacity quickly.”

Need for longer-term follow-up in healthcare

Routine follow-up after intensive care currently consists of a single visit three to six months after discharge. Longer follow-up occurs in some cases but is not standard practice.

“Our data show that the effects of severe COVID-19 often persist for several years. This supports the need for more long-term, multidisciplinary follow-up initiatives,” says Ingrid Didriksson.

About the study

Ingrid Didriksson defended her thesis “Biomarkers and outcomes in critically ill COVID-19 patients” in November 2025.

The research includes 498 patients with COVID-19 who received intensive care in Skåne between May 2020 and May 2021. Of these, 303 survived the acute phase and were followed up for three years. The study used stored blood samples from the SWECRIT biobank.

Calprotectin, a biomarker linked to the innate immune response, was analysed to explore potential long-term inflammatory processes. Levels were elevated during the acute illness and increased further during the first week, which may indicate a prolonged inflammatory response relevant to understanding post-COVID symptoms, although additional research is needed.

One sub-study examined clinical frailty. Patients identified as frail—meaning they had increased vulnerability to physiological stress—had higher mortality and poorer long-term recovery than other patients. These findings highlight the importance of early identification and tailored support to improve recovery prospects.