Results of pooled risks from meta-analyses
| Pooled ES (per age year) | Number of studies (n) | I2 (%) | |
| In-hospital mortality | |||
| All studies | 1.046 (1.038–1.054) | 31 | 93.2 |
| Age: continuous | 1.057 (1.047–1.067) | 16 | 64.1 |
| Age: categories | 1.037 (1.028–1.046) | 15 | 94.9 |
| Quality: high* | 1.057 (1.045–1.070) | 12 | 58.7 |
| Quality: low* | 1.057 (1.040–1.074) | 4 | 77.7 |
| Region: USA* | 1.059 (1.045–1.072) | 8 | 74.5 |
| Region: Europe* | 1.060 (1.044–1.077) | 5 | 40.3 |
| Region: China* | 1.041 (0.999–1.085) | 2 | 78.8 |
| Region: South Korea* | 1.055 (1.003–1.109) | 1 | – |
| Case mortality | |||
| All studies | 1.074 (1.061–1.087) | 11 | 85.3 |
| Age: continuous | 1.063 (1.043–1.084) | 3 | 68.7 |
| Age: categories | 1.078 (1.059–1.097) | 8 | 73.7 |
| Quality: high | 1.094 (1.082–1.106) | 2 | 0% |
| Quality: low | 1.069 (1.056–1.083) | 9 | 82.0 |
| Region: USA | 1.061 (1.048–1.073) | 5 | 67.1 |
| Region: Europe | 1.100 (1.075–1.125) | 3 | 76.6 |
| Region: South Africa | 1.072 (1.057–1.088) | 1 | – |
| Region: South America | 1.090 (1.058–1.122) | 1 | – |
| Region: China | 1.040 (1.015–1.065) | 1 | – |
| Hospitalisation | |||
| All studies | 1.034 (1.021–1.048) | 11 | 99.9 |
| Age: continuous | 1.039 (1.016–1.062) | 3 | 86.8 |
| Age: categories | 1.034 (1.018–1.049) | 8 | 99.9 |
| Quality: high | 1.051 (1.040–1.061) | 4 | 97.2 |
| Quality: low | 1.025 (1.019–1.032) | 7 | 98.1 |
| Region: USA | 1.033 (1.025–1.042) | 7 | 93.5 |
| Region: Europe | 1.047 (1.034–1.060) | 3 | 98.2 |
| Region: South America | 1.016 (1.016–1.017) | 1 | – |
| ICU admission | |||
| All studies | 1.006 (0.999–1.013) | 8 | 51.2 |
| Age: continuous | 1.003 (0.996–1.010) | 5 | 19.0 |
| Age: categories | 1.013 (0.998–1.028) | 3 | 31.6 |
| Quality: high | 1.004 (0.996–1.013) | 3 | 76.1 |
| Quality: low | 1.011 (0.996–1.026) | 5 | 30.7 |
| Region: USA | 1.007 (1.000–1.013) | 6 | 50.4 |
| Region: China | 1.033 (0.939–1.136) | 2 | 74.9 |
| Intubation | |||
| All studies | 1.006 (0.995–1.018) | 6 | 74.8 |
| Age: continuous | 1.008 (0.992–1.024) | 3 | 0.0 |
| Age: categories | 1.006 (0.991–1.021) | 3 | 88.1 |
*For age continuous.
ES, effect size; ICU, intensive care unit.