London, Apr 24 (IANS): One year after having Covid-19, only around one in four patients, who were hospitalised, felt fully well again, says a new study.

The study, published in The Lancet Respiratory Medicine, found that being female versus being male (32 per cent less likely), having obesity (half as likely) and having had mechanical ventilation in a hospital (58 per cent less likely) were all associated with a lower probability of feeling fully recovered at one year.

"We found female sex and obesity were major risk factors for not recovering at 1 year," said researcher Rachael Evans from the University of Leicester in the UK.

"In our clusters, female sex and obesity were also associated with more severe ongoing health impairments including reduced exercise performance and health-related quality of life at 1 year, potentially highlighting a group that might need higher intensity interventions such as supervised rehabilitation," Evans added.

The most common ongoing long-Covid symptoms were fatigue, muscle pain, physically slowing down, poor sleep, and breathlessness.

For the study, the team used data from the post-hospitalisation Covid-19 (PHOSP-COVID) study which assessed adults who had been hospitalised with Covid-19 across the UK and subsequently discharged.

A total of 2,320 participants discharged from the hospital between March 7, 2020, and April 18, 2021, were assessed five months after discharge and 807 (33 per cent) participants completed both the five-month and one-year visits at the time of analysis (and the study is ongoing).

These 807 patients had a mean age of 59 years, 279 (36 per cent) were women and 28 per cent received invasive mechanical ventilation.

The proportion of patients reporting full recovery was similar between 5 months (501 (26 per cent) of 1965) and 1 year (232 (29 per cent) of 804).

In an earlier publication from this study, the authors had identified four groups or 'clusters' of symptom severity at five months, which were confirmed by this new study at one year.

Of the 2,320 participants, 1,636 had sufficient data to allocate them to a cluster: 319 (20 per cent) had very severe physical and mental health impairment, 493 (30 per cent) had severe physical and mental health impairment, 179 (11 per cent) moderate physical health impairment with cognitive impairment, and 645 (39 per cent) mild mental and physical health impairment.

Having obesity, reduced exercise capacity, a greater number of symptoms, and increased levels of the inflammatory biomarker C-reactive protein were associated with the more severe clusters.