A meta-analysis led by University of Leicester researchers in the United Kingdom shows that nearly half of COVID-19 survivors around the world still had symptoms an average of 4 months later, regardless of whether they had been hospitalized.
The research, published yesterday in eClinicalMedicine, involved 194 studies of 735,006 participants with lingering COVID-19 symptoms at least 28 days after infection in Europe (106 studies), Asia (49), North America (26), South America (5), Africa (4), and Oceania (2) or multiple continents (2) from Dec 31, 2019, to Jan 21, 2022.
Of the 194 studies, each of which involved at least 100 participants, 5 were conducted in children aged 17 or younger and reported data on hospitalized (122 studies), nonhospitalized (18), or a combination of hospitalized and nonhospitalized (54) patients. Follow-up was 28 to 387 days.
At least 45% of COVID-19 survivors, on average, had at least one unresolved symptom at an average of 126 days. Fatigue was widely reported by hospitalized (28.4%), nonhospitalized (34.8%), and mixed (25.2%) cohorts. Other common symptoms were pain/discomfort (27.9%), impaired sleep (23.5%), breathlessness (22.6%), and impaired ability to participate in usual activities (22.3%).
Among hospital patients, abnormal computed tomography (CT) patterns/radiographs were often reported (45.3%), as were ground-glass opacities (hazy patches; 41.1%) and decreased capacity to diffuse carbon monoxide (31.7%).
"Current understanding is limited by heterogeneous study design, follow-up durations, and measurement methods," the study authors wrote. "Definition of subtypes of long Covid is unclear, subsequently hampering effective treatment/management strategies."
The researchers called for harmonization of data-collection tools to improve the clinical utility of findings from long-COVID systematic reviews, as well as more attention to the care of long-COVID patients.
"It is clear that given the high prevalence of persistent symptoms after 12 weeks (nearly 1 in 2 people) that healthcare services and policy need to prioritise long Covid care, and in addition understand different sub-types of long Covid to permit stratified healthcare and ensure services are not overwhelmed in future," they wrote.