Worldwide, 49% of COVID-19 survivors reported persistent symptoms 4 months after diagnosis, estimates a meta-analysis of 31 studies published late last week in The Journal of Infectious Diseases.University of Michigan researchers, who conducted a systematic review on Jul 5, 2021, also found the prevalence of long COVID at 1 month at 37%, while it was 25% at 2 months and 32% at 3 months.
Fifty studies were identified in the review, and 41 were included in a quantitative synthesis, and 31 reporting overall prevalence were meta-analyzed.The 50 studies included a total of 1,680,003 COVID-19 patients, including those who were hospitalized (67,161 patients from 22 studies), nonhospitalized (4,165 from 5 studies), and any COVID-19 patients, regardless of hospitalization status (1,608,677 from 23 studies).Impact on health, workforce 'enormous'Estimated global prevalence of long COVID was 43% (95% confidence interval [CI], 39% to 46%), although estimates ranged from 9% to 81%, which the study authors said may be attributable to differences in sex, region, study population, and follow-up.Long COVID prevalence among hospitalized patients was 54% (95% CI, 44% to 63%), while it was 34% (95% CI, 25% to 46%) for outpatients.Regionally, estimated pooled prevalence of lingering COVID-19 symptoms was 51% (95% CI, 37% to 65%) in Asia, 44% (95% CI, 32% to 56%) in Europe, 31% (95% CI, 21% to 43%) in North America, and 31% (95% CI, 22% to 43%) in the United States.Worldwide, estimated prevalence of long COVID was 37% (95% CI, 26% to 49%) 1 month after diagnosis, 25% (95% CI, 15% to 38%) at 2 months, 32% (95% CI, 14% to 57%) at 3 months, and 49% (95% CI, 40% to 59%) at 4 months.