The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the coronavirus disease 2019 (COVID-19) pandemic, which continues to cause immense social and economic disruptions worldwide. These effects are due to the high morbidity and mortality rates associated with COVID-19 and restrictions on human interactions due to public health interventions.

In addition to these acute effects, long-term symptoms have been reported by patients who have previously recovered from COVID-19, a condition now referred to as ‘long COVID.’ A new study posted to the preprint server medRxiv* discusses chronic disability due to long COVID in the United States.

Study: Physical and mental health disability associated with long-COVID: Baseline results from a US nationwide cohort. Image Credit: Anucha Naisuntorn

Introduction

Most measures implemented to manage COVID-19 were developed to prevent or limit the spread of SARS-CoV-2 and severe illness. However, over half of those who survive COVID-19 may develop persistent symptoms that vary between individuals and often affect more than one organ system.

Typically, long COVID is reported among previously hospitalized patients; however, the mild or moderate infection has also been shown to precipitate this syndrome. Similarly, both males and females can suffer from long COVID and those with or without pre-existing medical conditions.

About the study

There remains limited data on the extent to which long COVID symptoms affect the daily lives of those affected. However, earlier research found that up to half of COVID-19 survivors were still functioning below par six months following their recovery from the acute infection, with 10% severely limited in their ability to participate in independent daily activities. Several have confirmed these observations, in addition to reports of additional impairment of cognitive function.

Such impairments can affect the individual’s ability to be employed gainfully, be caregivers, and live independently. The current study at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, assessed adults who were self-reported to have or did not have a history of COVID-19.

The different outcomes assessed in the current study included disability related to mobility, in terms of being unable to easily walk a quarter of a mile and climb ten stairs, the ability to perform instrumental activities of daily living (IADL) such as light or heavy housework, as well as mental fatigue.

The researchers interviewed almost 8,000 adults, with a median age of 45 years, 84% female and nearly 90% white.

What did the study show?

Most of the study participants were unvaccinated at the time of their initial acute infection; however, the proportion was higher among those with long COVID. By the time the study began, about 60% of long COVID patients had received a primary course of an adenovirus or messenger ribonucleic acid (mRNA) vaccine.

Hospitalization was required among 13% of those with long COVID compared to about 2% of those in whom the infection was resolved.

Among those who had long COVID, about 75% had previously excellent health. However, less than 6% of the study participants reported that their health had been completely restored to pre-infection levels.

Physical activity was reported by about 70% of participants, irrespective of whether they had long COVID or not; however, half of those with long COVID stated their physical activity had declined after their COVID-19 diagnosis.

One-third of long COVID patients reported that they had become sedentary in place of their previously active lifestyle, comparable to only 3% of those who completely recovered from infection who were not sedentary.

About two-thirds of the participants who reported long COVID had one or more disabilities. This was in contrast to only one in seven of those without a history of COVID and less than 5% of those whose COVID-19 had resolved also reported one or more disabilities.

About 1% of those with long COVID had a critical physical disability compared to 5% with critical mental fatigue. Risk factors for significant disability included older age, having pre-existing illnesses, increased body mass index (BMI), and being female. This contrasts the male preponderance seen among cases of SARS-CoV-2 infection and severe COVID.

Patients hospitalized during their COVID-19 illness were at an increased risk of long COVID; however, 60% of non-hospitalized patients also reported a significantly high burden of disability, IADL, and mental fatigue. Over 20% of those who reported disability experienced impairment in all three categories, whereas around 5% had critical disability among non-hospitalized long COVID patients.

 These data suggest that factors predictive of hospitalization or severity of initial infection cannot be used to predict who will develop long-COVID-associated disability among those not requiring hospitalization.”

Mobility was impaired in over 40% compared to less than 3% of patients with long COVID and resolved COVID, respectively. This was comparable to less than 5% of those without a history of COVID-19. Severe disability in this regard was reported by 6%.

IADL impairment and severe impairment were reported in 57% and 12% of long COVID patients, respectively, but less than 3% among recovered patients. Those without a history of COVID-19 reported impairment in 10% of cases.

Long-COVID patients reported severe and critical mental fatigue in 7% and 5% of cases, respectively, compared to 0.2% with severe impairment and no critical impairment among those with resolved and no COVID.

Non-whites and those with multiracial ethnicity were at a higher risk for long COVID. In addition, dizziness during acute infection was common among hospitalized and non-hospitalized long COVID patients.

Among those not hospitalized with COVID-19, people who reported disability in four of five components had heavy limbs, difficulty breathing, and tremors during acute infection. Conversely, the same was true of those with heavy limbs among those who required hospitalization.

This could indicate the involvement of neurologic pathways that regulate posture and balance, including the autonomic nervous system. The association with limb heaviness might be due to cardiovascular involvement, reduced microvascular flow, clot formation, and injury to the endothelial lining of the blood vessels. Thus, the care of these patients should begin with evaluating multiple systems.

In both cohorts, individuals vaccinated before their infection had a 50% reduced risk of disabilities associated with long COVID. This could be partly because of the protection against severe infection following vaccination.

An increased rate of seeking medical care was observed among long COVID patients, as indicated by the number of new physician diagnoses. However, this is not synonymous with the complete restoration of functional ability and quality of life, as it prolongs the recovery of everyday social and economic conditions across society.

What are the implications?

The researchers observed a high prevalence of physical and mental disability related to long COVID that was almost 11 times greater among this group than those who had completely recovered from the viral infection. Notably, 1% of patients were critically disabled physically and unable to function, whereas 5% experienced critical mental fatigue.

These results indicate that one million or more of the 30-90 million people expected to have long COVID may be critically or seriously affected in their ability to live independently, earn a living, and take care of others. This has serious implications for both individual and societal health; however, the findings of this study demonstrate that these effects may be partially mitigated by vaccination.

Nevertheless, the effect of vaccination on disability due to prior infection remains unknown. Further research should focus on following up with COVID-19 patients to monitor their recovery course and prognosis and ensure the timely diagnosis and care for the wide range of impairments associated with long COVID.

*Important notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.