The pre-print study, which has yet to undergo peer review, concluded that those discharged from hospitals after receiving treatment for Covid-19 “face elevated rates of multiorgan dysfunction” and frequently require re-hospitalization, citing nearly 50,000 English patients reviewed in the research.

“Of 47,780 individuals in hospital with Covid-19 over the study period, 29.4 percent were readmitted and 12.3 percent died following discharge,” the paper said, with its authors noting that it is the largest study of its kind to date.

While much about what’s been dubbed “long Covid” or “Post Covid Syndrome” (PCS) – a condition in which symptoms of the virus, sometimes atypical ones, linger for months – remains unknown, a growing body of evidence suggests a large proportion of patients suffer symptoms well beyond their initial infection. Figures provided by the UK’s Office for National Statistics (ONS), for example, indicate that up to one-fifth of England’s coronavirus patients still experience symptoms five weeks after contracting the illness, while half of that number experience them for at least 12 weeks.

Studies on American military veterans showed that some 20 percent of those with Covid-19 had to return to hospital for treatment within 60 days of discharge, while nine percent died. Citing that research, the authors of the UK-based study said that Covid-19 was found to be “associated with increased odds of acute kidney injury, renal replacement therapy, insulin use, pulmonary embolism, stroke, myocarditis, arrhythmia, and elevated troponin.”

Spearheaded by lead author and principal statistician Daniel Ayoubkhan of the ONS, the new research on hospital readmissions concluded that “the long-term burden of Covid-related morbidity on hospitals and broader healthcare systems is likely to be substantial” given the high prevalence of PCS.

To date, the UK has tallied some 3.4 million coronavirus infections and just over 90,000 fatalities since the outbreak kicked off in late 2019, according to data compiled by Johns Hopkins University, putting it among the top-five worst-hit nations in terms of total case counts. While recent days have seen a gradual fall in new infections, the NHS’ National Medical Director Stephen Powis said on Monday that “severe pressure” on the healthcare system would likely not let up for some time, pointing to a more infectious variant of the virus that’s gripped large swaths of the country. His warning came as a nationwide lockdown remains in effect amid efforts to distribute one of several vaccines now approved for use in the UK.