Study identifies risk factors for long-haul COVID disease in adults

Mayo Clinic researchers have identified risk factors that can cause adult COVID-19 patients to suffer symptoms that linger for months or years. The condition is often referred to as long-haul COVID. The findings are reported in the Journal of Investigative Medicine.

Researchers surveyed more than 3,000 adults over the age of 18 who were treated via Mayo Clinic's virtual COVID-19 clinics in Florida, Arizona and Minnesota between March 2020 and March 2021.

They reviewed the patients' symptoms, the incidence of long-haul COVID in the group and how many were hospitalized due to COVID-19. The patients were also asked to rate their perception of the severity of their symptoms, whether they received a diagnosis of long-haul COVID, how long it took for them to resume their usual activities, and how much time they missed from work.

Study findings

"We found that patients with severe COVID-19 symptoms were more likely to have long-haul COVID than those who had mild symptoms," says Bala Munipalli, M.D., an internist at Mayo Clinic in Florida and co-senior author of the study. "A majority of these were women who had been hospitalized, suffered from psychological impacts from COVID-19 such as anxiety and depression, and required more than one month to return to their normal activities after the illness."

The average age of the respondents in the study was 54 and most were women, including 57% of the patients surveyed who reported severe symptoms; 60% with mild symptoms; and 65% with moderate symptoms.

Most patients (92%) with mild symptoms were able to resume their usual schedules within four weeks after COVID-19 infection, but 23% of these patients with mild acute infection developed long-haul COVID.

Significantly more (37.4%) patients with severe symptoms were hospitalized than those with mild (0.9%) or moderate symptoms (4.8%). Hospitalized patients also reported having persistent symptoms of long-haul COVID (67%), needing a month or more to resume their usual activities, missing work for at least three weeks, and having negative psychological side effects.

Most respondents in the study reported long-haul COVID symptoms that lasted three to six months, with those symptoms ranging in severity. The most common symptoms in the study group were fatigue, loss of smell, altered taste, shortness of breath and poor sleep.

More to learn

"The inability to resume normal activities within one month after acute COVID-19 may be a predictive factor for long-haul COVID. As we continue to study this disease, we hope to gain a better understanding of who is susceptible to it, the symptoms that remain persistent, and how to best manage these patients in the early course of their illness," says Dr. Munipalli.

"Additional studies may help guide the standardization of future assessment tools to evaluate impairment and also provide valuable information to employers, educators, policymakers and patients."

The researchers note that a multidisciplinary approach to long-haul COVID is needed and that health care personnel should recognize key symptoms, obtain a careful medical history and physical examination, as well as pay close attention to comorbid medical conditions in patients with persistent symptoms.

Dr. Munipalli says her team plans additional research focusing on treatments for long-haul COVID.