The risk for developing new clinical sequelae is increased after the acute phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), according to a study published online May 19 in The BMJ.

Sarah E. Daugherty, Ph.D., M.P.H., from OptumLabs at UnitedHealth Group in Minneapolis, and colleagues conducted a retrospective cohort study to examine the excess risk for developing incident clinical sequelae after the acute phase of SARS-CoV-2 infection in adults aged 18 to 65 years. The risks were compared to those of three propensity-matched comparator groups: a 2020 group, a historical 2019 group, and a historical comparator group with viral lower respiratory tract illness.

The researchers found that 14 percent of adults aged 65 years and younger with SARS-CoV-2 infection had at least one new type of clinical sequelae that necessitated medical care after the acute phase of illness; this was 4.95 percent higher than in the comparator group from 2020. Compared with the three comparator groups, the risk was increased for specific new sequelae attributable to SARS-CoV-2 infection after the acute phase, including chronic respiratory failure, cardiac arrhythmia, hypercoagulability, encephalopathy, peripheral neuropathy, amnesia, diabetes, liver test abnormalities, myocarditis, anxiety, and fatigue. Compared with the 2020 group, significant risk differences due to SARS-CoV-2 infection ranged from 0.02 to 2.26 per 100 people, and hazard ratios varied from 1.24 to 25.65.

"Health care professionals should be alert to the possibility of long COVID in anyone with confirmed or suspected COVID-19," write the authors of an accompanying editorial. "How to treat these longer term consequences is now an urgent research priority."