Global prevalence of long COVID ‘substantial,’ researchers say
Researchers estimated that more than 200 million people globally suffer from long-term effects of COVID-19, according to a recent study.
“There has been substantial confusion and heterogeneity about what fraction of COVID-19-diagnosed patients struggle with post-COVID conditions after the acute symptomatic phase of infection is over. There has been substantial ambiguity in the definition of ‘long COVID’ in the literature, and only recently, WHO proposed a clinical case definition of post-COVID-19 conditions,” Spencer R. Haupert, BS, an MS candidate in biostatistics at the University of Michigan School of Public Health, told Healio. “Prior to the introduction of this definition, studies have been reporting the presence of a cascade of symptoms at multiple time points after COVID diagnosis (30 days, 90 days, 6 months, 1 year). We wanted to synthesize the evidence from studies across the world and identify symptoms that are most commonly reported.”
Haupert and colleagues searched PubMed, Embase and iSearch from July 5, 2021, through March 13, 2022. The researchers examined the prevalence of post-COVID-19 condition starting 1 month after SARS-CoV-2 infection.
In total, 41 studies were ultimately included in the meta-analysis. The analysis demonstrated that the global estimated pooled prevalence of post-COVID-19 condition was “substantial” at 0.43 (95% CI, 0.39-0.46), with hospitalized and nonhospitalized patients having estimates of 0.54 (95% CI, 0.44-0.63) and 0.34 (95% CI, 0.25-0.46), respectively. Haupert added that these data, paired with recent WHO estimates of total global COVID-19 case counts, suggest that approximately 200 million people have had post-COVID-19 health consequences, with the most common symptoms being fatigue (23%), memory problems (14%), shortness of breath (13%), sleep problems (11%) and joint pain (10%). The prevalence estimates of these long-term symptoms at 30, 60, 90 and 120 days after infection were 37%, 25%, 32%, and 49%, respectively, according to the study.
Additionally, the study assessed data from more than 16 countries and showed that the prevalence of post-COVID-19 condition varies across geographic regions. The prevalence was highest in Asia (51%), followed by Europe (44%) and North America (31%).
Haupert added that research assessing the effect of vaccines on long COVID has been mixed but appears to show that the probability of long COVID after vaccination is reduced, “but once you have it, the types of symptoms and the duration still seem to be similar.”
“It would be difficult to overstate the global health implications of post-COVID-19 condition,” Haupert said. “This is, of course, a major health care burden but may also hinder economic productivity because of the ensuing disability post-COVID-19 condition can cause in the labor force.”
He added that “nations would need to take a proactive approach and have a health and economic support system” for patients with long COVID.