By Gareth Kantor.
Most research has focused on the acute effects of Covid-19, including the devastating burden of severe disease, hospitalization and death that has resulted. But a significant number of patients experience a variety of long-term effects, troublesome symptoms that reduce quality of life, even after only a mild Covid-19 illness.
10-20% of Covid-19 patients report one or more persistent symptoms 2 months later1,2,3, an increasing concern for them, for clinicians and for health system administrators. This chronic illness has become known as “Long Covid” (LC). “Activist” patients4 have played an important role bringing it to public attention but a consensus definition of Long Covid does not yet exist.
Long Covid appears similar in some respects to chronic fatigue syndrome (full name: myalgic encephalitis / chronic fatigue syndrome – ME/CFS) which affects up to 2.5 million Americans5 and whose cause is unknown, but also suspected to be linked to preceding viral infection.
EFFECTS OF LONG COVID
Patients with other kinds of critical illness need weeks, months or years to recover. Many never return to their previous state of health. An unusual aspect of Long Covid is that patients with even mild infection report a wide range of chronic symptoms.
We expect to recover from other mild coronavirus infections, such as the common cold, without prolonged harm to our health, so what’s the biological basis of this phenomenon?
Two main theories:
- One is that persisting low-level presence of the virus or parts of the virus somewhere in the body generates ongoing inflammation.
- Another possibility is that the infection has primed the immune system to attack the body’s own tissues.
The symptoms of Long Covid may also be related to the significant stress and anxiety experienced by a large proportion of the population during this pandemic.
ASK THE PATIENT
A good way to find out about Long Covid is to just ask the patient – but in a scientific fashion. Patient-reported outcome measures (PROMs)7 are validated measurement tools for assessing symptom burden, functional loss, and health-related quality of life.
A study from Italy8 early in the pandemic (May 2020) followed 143 patients after hospitalization for severe COVID. They were assessed about 2 months after onset of their illness:
- Average age of these patients was 56.5 most (63%) were male.
- At the time of evaluation, only 12.6% were completely free of any COVID-19–related symptoms
- 32% had 1 or 2 symptoms and 55% had 3 or more
- Quality of life was reported to be worse by 44.1% of patients
- 1% still had fatigue and 43.4% were experiencing shortness of breath
- Joint pain was reported by 27.3% and chest pain 21.7% of patients
Limitations of this study included the lack of information on symptoms before acute COVID-19 illness and the lack of scoring of symptom severity. There was no control group of patients admitted to hospital for other reasons.
The burden of LC can be better measured by using specific, validated PROMs designed to address symptoms and their impact, including reduced health-related quality of life. We also need to know about similar symptoms before the onset of infection and should compare findings to patients who were exposed to Covid-19 but did not become infected (i.e. a control group). Patients with other common illnesses (e.g. community-acquired pneumonia, heart attack or other illness requiring hospital admission) are also a basis for comparison.
A more recent (January 2021) report9, from the US, illustrates aspects of a more scientific approach. They looked at adult patients hospitalised with severe COVID-19.
- Of 152 respondents, median age 62 years, 37% were female
- Patients had intact baseline cognition and functional status
- Two validated PROMs – the PROMIS® Dyspnea Characteristics and PROMIS® Global Health-10 – were used.
Among the findings:
- Impaired breathing, physical health and mental health for at least several weeks after hospital discharge.
- 74% reported shortness of breath – but 31% had symptoms before COVID-19 infection
- Participants rated their physical health and mental health as worse (43.8) than their pre- COVID (54.3) state. [Using these PROMs, physical and mental health average scores in the general US population are 50 (SD 10)].
- More than a third (35.1%) of patients needed oxygen at home after hospital discharge and 13.5% reported still using oxygen at time of the survey.
MORE STUDY IN SOUTH AFRICA IS NEEDED
With over 1.5m cases so far reported, 150-300,000 South Africans may be suffering from Long Covid. Insight will soon publish figures that may help to more precisely estimate the current burden of Long Covid, and assist with planning and resource allocation. A platform for scientifically measuring LC disease burden, from the patient perspective, is now available from Insight.
The US National Institutes of Health have allocated $1.15B in funding to study LC over the next 4 years10. More study of the long-term effects of Covid-19 disease is needed in SA too.
Monitoring after hospital discharge, or after confirmed diagnosis, using electronically administered PROMs (“ePROMS”), is a convenient, inexpensive and more precise way to assess the course and impact of mild and severe disease. South African medical schemes and others can use ePROMs to study the impact of their members using a POPIA-compliant platform called Voice of the Patient that is available from Insight. We use validated PROMs11,12 that will enable comparison locally and with overseas experience.
Interestingly, some patients with LC report that their symptoms are reduced or have disappeared after vaccination13. These early findings provide hope of prevention and recovery if we can get Covid-19 vaccines to most South Africans this year.
The prolonged effects of Covid-19 on patients and the health care system need to be better understood and managed, and the tools with which to achieve these insights are now available.
1 COVID Symptom Study – Help slow the spread of COVID-19. https://covid.joinzoe.com/.
2 Stavem, K., Ghanima, W., Olsen, M. K., Gilboe, H. M. & Einvik, G. Persistent symptoms 1.5-6 months after COVID-19 in non-hospitalised subjects: A population-based cohort study. Thorax 76, 405 (2020).
3 Overview | COVID-19 rapid guideline: managing the long-term effects of COVID-19 | Guidance | NICE.
4 Callard, F. & Perego, E. How and why patients made Long Covid. Soc. Sci. Med.268, 113426 (2021).
5. What is ME/CFS? | Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) | CDC. https://www.cdc.gov/me-cfs/about/index.html.
6 Post-COVID Conditions | CDC. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects.html.
7 Patient-reported outcome measures (PROMs) | CIHI. https://www.cihi.ca/en/patient-reported-outcome-measures-proms.
8 Carfì, A., Bernabei, R. & Landi, F. Persistent symptoms in patients after acute COVID-19. JAMA – Journal of the American Medical Association vol. 324 603–605 (2020).
9 Weerahandi, H. et al. Post-Discharge Health Status and Symptoms in Patients with Severe COVID-19. J. Gen. Intern. Med. (2021) doi:10.1007/s11606-020-06338-4.
10 NIH launches new initiative to study “Long COVID” | National Institutes of Health (NIH). https://www.nih.gov/about-nih/who-we-are/nih-director/statements/nih-launches-new-initiative-study-long-covid.
11 PROMIS. https://www.healthmeasures.net/explore-measurement-systems/promis?AspxAutoDetectCookieSup=.
12 C19-YRS – COVID-19 Yorkshire Rehabilitation Scale. https://c19-yrs.com/.
13 Dt, A. et al. Are vaccines safe in patients with Long COVID? A prospective observational study. Introduction. medRxiv 2021.03.11.21253225 (2021) doi:10.1101/2021.03.11.21253225
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