Researchers in Canada have conducted a study suggesting that the majority of patients living with long COVID (coronavirus disease) following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience chronic fatigue that is at least as severe as that seen in several other clinical conditions.
The team from the University of Calgary in Alabama and Breath Well Physio in Calgary say that post-exertional malaise (PEM) appears to be a significant challenge for the majority of these patients, reducing their capacity to work and be physically active.
Rosie Twomey and colleagues say that the study of more than 200 participants found that the impact of long COVID on health-related quality of life was substantial, despite a relatively young cohort where almost half of participants had no comorbidities.
“Patients, researchers, and allied health professionals are seeking information on safe rehabilitation for people living with long COVID, particularly regarding exercise,” writes the team. “Fatigue and post-exertional symptom exacerbation must be monitored and reported in studies involving interventions for people with long COVID.”
A pre-print version of the research paper is available on the medRxiv* server, while the article undergoes peer review.
Long COVID is a major public health concern
Long COVID is a major public health concern, with estimates suggesting that around 14% of people who become infected with SARS-CoV-2 will continue to experience symptoms 12 weeks later. Moreover, long COVID does not only affect patients that require hospitalization or those with comorbidities. Even individuals who are at low risk of COVID-19 mortality may experience chronic symptoms and impaired function of one or more organs.
A visualization of the impact of long COVID on health-related quality of life measured using eight SF-36 subscales. Mean scores from the present study are presented alongside data from the general population (normative), rheumatoid arthritis (RA), and chronic obstructive pulmonary disease (COPD).
Chronic fatigue is consistently the most frequently reported symptom of long COVID. The condition is characterized by a persistent feeling of tiredness or exhaustion that is not proportional to recent activity levels and is not alleviated by rest.
“Reports of persistent fatigue alongside fluctuating symptoms that worsen unpredictably or in response to exertion have led to comparisons between long COVID and other post-viral conditions, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS),” writes Twomey and colleagues.
One of the hallmark symptoms of ME/CFS is PEM, which describes a worsening of symptoms and reduced function following physical, cognitive, or emotional activity that would not have posed a problem prior to illness developing.
“However, the presence of PEM in people living with long COVID has not been clearly identified using self-report tools that are validated in people with ME/CFS,” say the researchers.
A more detailed assessment of chronic fatigue and PEM among people living with long COVID may help to inform the development of physiotherapy and rehabilitation recommendations, suggests the team.
What did the researchers do?
The researchers used validated questionnaires to measure the severity of fatigue among adults living with long COVID and compared the findings with normative data and thresholds for clinical relevance in other diseases.
They assessed PEM screening methods recommended for use in people living with ME/CFS and measured symptoms of dysfunctional breathing, self-reported physical activity or sitting time, and health-related quality of life.
The study was conducted as an online survey involving 213 participants, with data collected between February 11th and April 25th, 2021.
Questionnaires included the Functional Assessment of Chronic Illness Therapy-Fatigue Scale (FACIT-F), the DePaul Symptom Questionnaire-Post-Exertional Malaise (DSQ-PEM) and the Self-Evaluation of Breathing Questionnaire (SEBQ).
Health-related quality of life was also measured using the Short-Form Health Survey (SF-36), and physical activity and sitting time were measured using the International Physical Activity Questionnaire-Short Form (IPAQ-SF).
What did the study find?
The majority (85.5%) of participants identified as women, with most (78.4%) aged 40 to 59 years.
Most participants (72.3%) had been experiencing long COVID symptoms for 6 months or longer and a large proportion (46.5%) had no medical conditions that pre-dated the illness.
A large proportion (42.3%) reported that long COVID was preventing them from working, and 41.8% said the illness had reduced their capacity to work or the hours they were able to work. Only 5.2% of the participants were able to continue working as usual.
The total FACIT-F score was 18±10 (score range 0-52, with a lower score indicating more severe fatigue), and 71.4% were experiencing chronic fatigue, with symptoms persisting for 3 months or more.
Most participants were affected by PEM and 58.7% met the scoring thresholds used for people living with ME/CSF.
Participants who experienced a worsening of symptoms following exertion also reported reduced physical and social functioning.
According to the SF-36 results, factors that were most impacted by long COVID were role limitations due to physical health problems and fatigue.
“Symptom exacerbation must be considered in rehabilitation and exercise interventions for people living with long COVID,” says Twomey and colleagues. “In people with PEM, an activity plan needs to be carefully designed based on individual presentation with input from each patient.”
The total SEBQ score was 30 ± 17 (score range 0 to 75, with a higher score indicating more severe symptoms). Furthermore, 54.0% of participants had a score of more than 25, indicating significant breathing discomfort.
“Respiratory physiotherapy and breathing retraining may be helpful for people with breathing discomfort,” suggests the team.
“Long COVID is characterized by chronic fatigue that is clinically relevant and is at least as severe as fatigue in several other clinical conditions,” writes Twomey and colleagues.
PEM seems to be a common and significant challenge for the majority of this patient group and occurs alongside a reduced capacity to work and function both physically and socially, they add.
“Because people with long COVID report setbacks and deterioration in function following overexertion, fatigue and post-exertional symptom exacerbation must be monitored and reported in studies involving interventions for people with long COVID,” the team concludes.
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.