Background This study provides the first systematic review and meta-analysis to identify the predictors of unfavorable prognosis of COVID-19 in children and adolescents. Methods We searched literature databases until July 2021 for studies that investigated risk factors for unfavorable prognosis of children and adolescents with COVID-19. We used random-effects models to estimate the effect size with 95% confidence interval (CI). Findings We identified 56 studies comprising 79,104 individuals. Mortality was higher in patients with multisystem inflammatory syndrome (MIS-C) (odds ratio [OR]=58.00, 95% CI 6.39–526.79) and who were admitted to intensive care (OR=12.64, 95% CI 3.42–46.68). Acute respiratry distress syndrme (ARDS) (OR=29.54, 95% CI 12.69–68.78) and acute kidney injury (AKI) (OR=55.02, 95% CI 6.26–483.35) increased the odds to be admitted to intensive care; shortness of breath (OR=16.96, 95% CI 7.66–37.51) increased the need of respiratory support; and neurological diseases (OR=5.16, 95% CI 2.30–11.60), C-reactive protein (CRP) level ≥80 mg/L (OR=11.70, 95% CI 4.37–31.37) and D-dimer level ≥0.5ug/mL (OR=20.40, 95% CI 1.76–236.44) increased the odds of progression to severe or critical disease. Interpretation Congenital heart disease, chronic pulmonary disease, neurological diseases, obesity, MIS-C, shortness of breath, ARDS, AKI, gastrointestinal symptoms, elevated CRP and D-dimer are associated with unfavourable prognosis in children and adolescents with COVID-19.

  • Newborn (0-1 years)
  • Children (2-9 years)
  • Adolescents (10-18 years)
  • Risk factor
  • COVID-19