Global Prevalence of Long COVID, Its Subtypes, and Risk Factors: An Updated Systematic Review and Meta-analysis

Abstract

Background. This mega-systematic review evaluated the global prevalence of long COVID and its subtypes and symptoms, and assessed the effects of risk factors for long COVID. Methods. Studies published from 5 July 2021 to 29 May 2024 were searched in PubMed, Embase, and Web of Science, with supplemental updates on 23 July 2024. Data were pooled using a random-effects framework with DerSimonian-Laird estimator. Risk of bias analysis was conducted. Results. A total of 429 studies were meta-analyzed. The global pooled long COVID prevalence was 36% (95% confidence interval [CI], 33%–40%) with 144 contributing studies. The highest prevalence rates were observed in South America (51% [95% CI, 35%–66%]). The prevalence of long COVID persisted over time, with 35% (95% CI, 31%–39%) at <1 year of followup and 46% (95% CI, 37%–57%) at 1–2 years. The most prevalent subtypes were respiratory (20% [95% CI, 14%–28%]) estimated from 31 studies, general fatigue (20% [95% CI, 18%–23%]) from 119 studies, psychological (18% [95% CI, 11%–28%]) from 10 studies, and neurological (16% [95% CI, 8%–30%]) from 23 studies. The 3 strongest risk factors were being unvaccinated for COVID-19 (pooled odds ratio [OR], 2.09 [95% CI, 1.55–2.81]) meta-analyzed from 7 studies, infections from pre-Omicron variants (OR, 1.74 [95% CI, 1.40–2.17]) from 6 studies, and female sex (OR, 1.56 [95% CI, 1.32–1.84]) from 33 studies. Conclusions. Long COVID is globally prevalent after a severe acute respiratory syndrome coronavirus 2 infection, highlighting a continuing health challenge. The heterogeneity of estimates across populations argues the need for well-designed follow-up studies that use consistent measures and are globally representative.