Table 2

Results of pooled risks from meta-analyses

Pooled ES (per age year)Number of studies (n)I2 (%)
In-hospital mortality
 All studies1.046 (1.038–1.054)3193.2
 Age: continuous1.057 (1.047–1.067)1664.1
 Age: categories1.037 (1.028–1.046)1594.9
 Quality: high*1.057 (1.045–1.070)1258.7
 Quality: low*1.057 (1.040–1.074)477.7
 Region: USA*1.059 (1.045–1.072)874.5
 Region: Europe*1.060 (1.044–1.077)540.3
 Region: China*1.041 (0.999–1.085)278.8
 Region: South Korea*1.055 (1.003–1.109)1
Case mortality
 All studies1.074 (1.061–1.087)1185.3
 Age: continuous1.063 (1.043–1.084)368.7
 Age: categories1.078 (1.059–1.097)873.7
 Quality: high1.094 (1.082–1.106)20%
 Quality: low1.069 (1.056–1.083)982.0
 Region: USA1.061 (1.048–1.073)567.1
 Region: Europe1.100 (1.075–1.125)376.6
 Region: South Africa1.072 (1.057–1.088)1
 Region: South America1.090 (1.058–1.122)1
 Region: China1.040 (1.015–1.065)1
Hospitalisation
 All studies1.034 (1.021–1.048)1199.9
 Age: continuous1.039 (1.016–1.062)386.8
 Age: categories1.034 (1.018–1.049)899.9
 Quality: high1.051 (1.040–1.061)497.2
 Quality: low1.025 (1.019–1.032)798.1
 Region: USA1.033 (1.025–1.042)793.5
 Region: Europe1.047 (1.034–1.060)398.2
 Region: South America1.016 (1.016–1.017)1
ICU admission
 All studies1.006 (0.999–1.013)851.2
 Age: continuous1.003 (0.996–1.010)519.0
 Age: categories1.013 (0.998–1.028)331.6
 Quality: high1.004 (0.996–1.013)376.1
 Quality: low1.011 (0.996–1.026)530.7
 Region: USA1.007 (1.000–1.013)650.4
 Region: China1.033 (0.939–1.136)274.9
Intubation
 All studies1.006 (0.995–1.018)674.8
 Age: continuous1.008 (0.992–1.024)30.0
 Age: categories1.006 (0.991–1.021)388.1
  • *For age continuous.

  • ES, effect size; ICU, intensive care unit.