Table 4 Risk factors in patients with VAE compared with patients with VAP in all included studies
| Â | Studies (n) | Patients with VAE (n) | Patients with VAP (n) | Estimate (OR/WMD) | 95 % Confidence interval (%) | Heterogeneity | Publication biasc | Effect model | ||
|---|---|---|---|---|---|---|---|---|---|---|
I 2 (%) | P | t value (Egger’s test) | P | |||||||
VAC | ||||||||||
 Age | 1 | 37 | 121 | 0.00a | −5.89, 5.89 | NA | NA | NA | NA | NA |
 Sex (male/female) | 3 | 551 | 255 | 0.85b | 0.59, 1.21 | 20.60 | 0.28 | −2.68 | 0.24 | Fixed |
 APACHE | 1 | 387 | 83 | 5.00a | −1.67, 11.67 | NA | NA | NA | NA | NA |
 Ventilated duration (days) | 3 | 569 | 299 | −2.79a | −4.79, −0.80 | 0.00 | 0.81 | −3.39 | 0.18 | Fixed |
 Death in hospital | 5 | 857 | 393 | 1.49b | 1.11, 2.01 | 53.10 | 0.07 | −1.37 | 0.27 | Fixed |
 Length of stay (days) | ||||||||||
  In hospital | 4 | 1244 | 329 | −4.27a | −7.00, −1.55 | 47.40 | 0.13 | 0.20 | 0.94 | Fixed |
  In ICU | 2 | 802 | 81 | −0.64a | −5.84, 4.55 | 74.50 | 0.05 | NA | NA | Random |
IVAC | ||||||||||
 Age | 1 | 31 | 121 | 0.00a | −6.63, 6.63 | NA | NA | NA | NA | NA |
 Sex (male/female) | 3 | 406 | 268 | 1.05b | 0.70, 1.59 | 0.00 | 0.46 | 0.29 | 0.82 | Fixed |
 APACHE | 1 | 344 | 83 | 4.00a | −2.53, 10.53 | NA | NA | NA | NA | NA |
 Ventilated duration (days) | 2 | 384 | 248 | −2.89a | −5.58, −0.20 | 0.00 | 0.80 | NA | NA | Fixed |
 Death in hospital | 4 | 446 | 423 | 1.76b | 1.23, 2.52 | 0.00 | 0.77 | 0.50 | 0.67 | Fixed |
 Length of stay (days) | ||||||||||
  In hospital | 2 | 384 | 248 | −5.86a | −9.46, −2.25 | 0.00 | 0.92 | NA | NA | Fixed |
  In ICU | 0 | 0 | 0 | NA | NA | NA | NA | NA | NA | NA |