Characterising long COVID: a living systematic review

Abstract

BackgroundWhile it is now apparent clinical sequelae (long COVID) may persist after acute COVID-19, their nature, frequency and aetiology are poorly characterised. This study aims to regularly synthesise evidence on long COVID characteristics, to help inform clinical management, rehabilitation strategies and interventional studies to improve long-term outcomes.MethodsA living systematic review. Medline, CINAHL (EBSCO), Global Health (Ovid), WHO Global Research on COVID-19 database, LitCovid and Google Scholar were searched till 17 March 2021. Studies including at least 100 people with confirmed or clinically suspected COVID-19 at 12 weeks or more post onset were included. Risk of bias was assessed using the tool produced by Hoy et al. Results were analysed using descriptive statistics and meta-analyses to estimate prevalence.ResultsA total of 39 studies were included: 32 cohort, 6 cross-sectional and 1 case–control. Most showed high or moderate risk of bias. None were set in low-income countries and few included children. Studies reported on 10 951 people (48% female) in 12 countries. Most included previously hospitalised people (78%, 8520/10 951). The longest mean follow-up time was 221.7 (SD: 10.9) days post COVID-19 onset. Over 60 physical and psychological signs and symptoms with wide prevalence were reported, most commonly weakness (41%; 95% CI 25% to 59%), general malaise (33%; 95% CI 15% to 57%), fatigue (31%; 95% CI 24% to 39%), concentration impairment (26%; 95% CI 21% to 32%) and breathlessness (25%; 95% CI 18% to 34%). 37% (95% CI 18% to 60%) of patients reported reduced quality of life; 26% (10/39) of studies presented evidence of reduced pulmonary function.ConclusionLong COVID is a complex condition with prolonged heterogeneous symptoms. The nature of studies precludes a precise case definition or risk evaluation. There is an urgent need for prospective, robust, standardised, controlled studies into aetiology, risk factors and biomarkers to characterise long COVID in different at-risk populations and settings.PROSPERO registration numberCRD42020211131.

Prevalence of long-term effects in individuals diagnosed with COVID-19: an updated living systematic review

“…We wanted to identify all possible symptoms that may be associated with post COVID-19 condition, therefore we did not restrict inclusion of studies in our review, nor our syntheses of the findings, to only select symptoms, whereas other reviews did (21,24,26). Other reviews also excluded studies with less than 100 participants (23, 25) while our review included relevant studies with a sample size of 50 or more; thereby increasing our likelihood of capturing additional relevant studies compared to others. Some reviews included studies with follow-up periods occurring between 2 and 3 weeks post-infection (19-21,25).…”

Post COVID-19 in children, adolescents, and adults: results of a matched cohort study including more than 150,000 individuals with COVID-19

“…Symptoms frequently observed include fatigue, weakness, muscle pain, sleep disorders, depressive symptoms, dizziness, lack of memory and concentration, and shortness of breath. This has been observed mainly among adults [8,9,11], whereas evidence on pediatric populations is still very limited [10,12,13].…”

Persistent Post COVID-19 Symptoms and Functional Status after 12-14 weeks of recovery, Tamil Nadu, India, 2021

“… 2 , 3 , 4 Long COVID symptoms were reported in 12 countries and none were from LMIC. 5 The proportion of the Indian Population who have been experiencing the symptoms following the recovery is unknown. Understanding the burden of post COVID-19 symptoms is vital in planning the health systems for essential Post COVID care.…”

“…The prevalence of at least one persistent symptom in our study was lower than the studies from high income countries. 5 , 8 Weakness, general malaise, fatigue, brain fog, and breathlessness were the most commonly reported long COVID-19 symptoms in high income countries. 5 On the other hand, weight loss, hair loss, and excessive tiredness were the most common reported symptoms in our setting.…”

“… 5 , 8 Weakness, general malaise, fatigue, brain fog, and breathlessness were the most commonly reported long COVID-19 symptoms in high income countries. 5 On the other hand, weight loss, hair loss, and excessive tiredness were the most common reported symptoms in our setting. Globally, almost one in four reported brain fog and breathlessness post COVID-19 compared to 2% and 6% respectively in Chennai.…”