Table 2 The results of pooled prevalence of VAE and VAP in included studies
| Â | Studies (n) | Sample size, (n) | Prevalence (%) | 95 % Confidence interval (%) | Heterogeneity | Publication biasa | Effect model | ||
|---|---|---|---|---|---|---|---|---|---|
I 2 (%) | P | t value (Egger test) | P | ||||||
VAC | |||||||||
 MV >0 day | 17 | 68747 | 13.8 | 9.0, 18.6 | 99.8 | <0.01 | 1.54 | 0.15 | Random |
 MV ≥2 days | 13 | 25935 | 20.1 | 9.6, 30.6 | 99.8 | <0.01 | 0.53 | 0.60 | Random |
 MV ≥3 days | 5 | 19408 | 26.9 | 5.0, 48.8 | 99.9 | <0.01 | 0.69 | 0.54 | Random |
 MV ≥4 days | 4 | 9349 | 30.7 | −1.5, 62.9 | 99.9 | <0.01 | 0.05 | 0.97 | Random |
 MV ≥5 days | 1 | 3028 | 77.0 | 75.5, 78.5 | NA | NA | NA | NA | NA |
IVAC | |||||||||
 MV >0 day | 14 | 55430 | 6.4 | 4.8, 8.1 | 99.0 | <0.01 | 2.15 | 0.05 | Random |
 MV ≥2 days | 10 | 21558 | 9.6 | 5.8, 13.3 | 99.1 | <0.01 | 1.22 | 0.26 | Random |
 MV ≥3 days | 3 | 15944 | 14.8 | 3.9, 25.7 | 99.7 | <0.01 | 2.60 | 0.23 | Random |
 MV ≥4 days | 2 | 5885 | 20.4 | 4.0, 36.7 | 99.6 | <0.01 | NA | NA | Random |
 MV ≥5 days | 1 | 3028 | 28.7 | 27.0, 30.0 | NA | NA | NA | NA | NA |
Possible VAP | |||||||||
 MV >0 day | 7 | 46820 | 1.1 | 0.5, 1.7 | 97.2 | <0.01 | 0.98 | 0.37 | Random |
 MV ≥2 days | 4 | 16205 | 2.5 | 0.8, 4.1 | 98.7 | <0.01 | 1.23 | 0.34 | Random |
 MV ≥3 days | 2 | 12916 | 4.5 | −0.9, 10.0 | 99.3 | <0.01 | NA | NA | Random |
 MV ≥4 days | 1 | 2857 | 8.5 | 7.0, 10.0 | NA | NA | NA | NA | NA |
 MV ≥5 days | 0 | NA | NA | NA | NA | NA | NA | NA | NA |
Probable VAP | |||||||||
 MV >0 day | 8 | 47524 | 0.9 | 0.6, 1.2 | 91.7 | <0.01 | 1.14 | 0.30 | Random |
 MV ≥2 days | 5 | 16642 | 1.6 | 0.8, 2.5 | 94.9 | <0.01 | 1.05 | 0.37 | Random |
 MV ≥3 days | 2 | 12916 | 1.7 | 1.5, 1.9 | 0.0 | 0.378 | NA | NA | Fixed |
 MV ≥4 days | 1 | 2557 | 2.2 | 2.0, 3.0 | NA | NA | NA | NA | NA |
 MV ≥5 days | 0 | NA | NA | NA | NA | NA | NA | NA | NA |
VAP | |||||||||
 MV >0 day | 10 | 17914 | 11.9 | 9.4, 14.4 | 99.5 | <0.01 | 3.64 | <0.01 | Random |
 MV ≥2 days | 10 | 12552 | 13.7 | 9.3, 18.1 | 99.5 | <0.01 | 3.79 | <0.01 | Random |
 MV ≥3 days | 2 | 6341 | 14.7 | −9.2, 38.7 | 99.9 | <0.01 | NA | NA | Random |
 MV ≥4 days | 2 | 5885 | 14.9 | −8.6, 38.5 | 99.9 | <0.01 | NA | NA | Random |
 MV ≥5 days | 1 | 3028 | 26.9 | 25.0, 29.0 | NA | NA | NA | NA | NA |