Just one in four patients who was hospitalised with Covid is fully recovered a year later, a major study suggests.

The research involving more than 2,000 patients in the UK shows that women, those who are obese and those who ended up on a ventilator were most likely to struggle with long Covid.

Scientists said there was an “urgent need” for the NHS to support a rapidly increasing group of patients, who currently have no specific treatments available.

The new study suggests that poor recovery from Covid is associated with inflammation of key proteins, which experts said should be targeted in the hunt for an effective cure.

More than 830,000 patients have been hospitalised with Covid in the UK since the start of the pandemic, official figures show.

The study, published in The Lancet Respiratory Medicine and presented at the European Congress of Clinical Microbiology & Infectious Diseases, tracked patients treated at 39 NHS hospitals in the UK.

In total, 2,320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed five months after discharge. Of those, 807 participants were still being tracked at 12 months.

Overall, just 29 per cent were fully recovered – with women 32 per cent less likely to have made a full recovery, while those who were obese were half as likely to have reached this point. Those whose hospital stay involved mechanical ventilation were 58 per cent less likely to have fully recovered, the research found.

Researchers found similar trends at five months, when just 26 per cent were fully recovered, suggesting that progress in the first few months after hospitalisation is key.

In almost half of cases, symptom severity at five months was classed as severe or very severe.

Debilitating symptoms 

The most common ongoing long Covid symptoms were fatigue, muscle pain, physically slowing down, poor sleep, and breathlessness. Those tracked for 12 months had a mean age of 59, with one in three female, and more than a quarter having been on ventilators.

Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at five months and one year after hospital discharge.

Researchers also took samples of participants’ blood at the five-month visit to analyse it for the presence of various inflammatory proteins.

Increased levels of the inflammatory biomarker C-reactive protein were associated with the more severe forms of long Covid, and levels of the inflammatory biomarker interleukin-6 (IL-6) were also found to be raised.

Those who were obese and had reduced exercise capacity were also more likely to suffer badly.

Data from the Office for National Statistics suggests that around 1.7million people are currently experiencing long Covid, which is defined as symptoms that persist for more than four weeks after suspected infection.

Urgent need for support

The new study was led by Prof Christopher Brightling, Dr Rachael Evans, and Prof Louise Wain, from the National Institute for Health Research Leicester Biomedical Research Centre at the University of Leicester.

Dr Evans said the limited recovery between five months and one year after hospitalisations was “striking”, with the majority struggling with symptoms including organ impairment, lost capacity to exercise and a deterioration in mental health.

Being obese or female were found to be “major major risk factors for not recovering at one year,” she said, suggesting such groups might need higher intensity interventions such as supervised rehabilitation.

Prof Wain said: “No specific therapeutics exist for long Covid and our data highlight that effective interventions are urgently required. Our findings of persistent systemic inflammation, particularly in those in the very severe and moderate with cognitive impairment clusters, suggest that these groups might respond to anti-inflammatory strategies.”

Some patients might also need therapy to manage post-traumatic stress disorder, she said.

Prof Brightling said: “Our study highlights an urgent need for healthcare services to support this large and rapidly increasing patient population in whom a substantial burden of symptoms exist, including reduced exercise capacity and substantially decreased health-related quality of life one year after hospital discharge.

“Without effective treatments, long Covid could become a highly prevalent new long-term condition.”