Table 3.
Summary of subgroup analysis according to principal diagnosis
| Analysis | First objective | Secondary objective | ||||
|---|---|---|---|---|---|---|
| Unadjusted effect size | Adjusted effect size | SMD | ||||
| RR | OR | RR | OR | Maximum PaO2 | Mean PaO2 | |
| Overall | 22 studies | 22 studies | 11 studies | 12 studies | 15 studies | 13 studies |
| Random-effects | 1.13 (1.05, 1.23)* | 1.37 (1.11, 1.68)* | 1.26 (1.12, 1.41)* | 1.55 (1.21, 1.99)* | 0.17 (0.04, 0.30)* | 0.25 (0.04, 0.45)* |
| Fixed-effect | 1.10 (1.05, 1.15)* | 1.30 (1.14, 1.48)* | 1.26 (1.18, 1.34)* | 1.49 (1.27, 1.74)* | 0.14 (0.08, 0.19)* | 0.16 (0.10, 0.21)* |
| Trim and fill method | 1.12 (1.03, 1.21)* | 1.31 (1.07, 1.61)* | 1.26 (1.12, 1.41)* | 1.42 (1.09, 1.85)* | Not performed | Not performed |
| Subgroup analysis according to principal diagnosis | ||||||
| TBI | 3 studies | 3 studies | 1 study | 2 studies | 1 study | 1 study |
| Random-effects | 1.21 (0.98, 1.51) | 1.44 (0.91, 2.29) | 1.05 (0.67, 1.66) | 1.47 (1.16, 1.87)* | − 0.47 (− 0.82, − 0.12)* | − 0.47 (− 0.82, − 0.12)* |
| Fixed-effect | 1.21 (0.98, 1.51) | 1.44 (0.91, 2.29) | 1.05 (0.67, 1.66) | 1.47 (1.16, 1.87)* | − 0.47 (− 0.82, − 0.12)* | − 0.47 (− 0.82, − 0.12)* |
| CA | 12 studies | 12 studies | 6 studies | 6 studies | 10 studies | 7 studies |
| Random-effects | 1.05 (0.96, 1.15) | 1.13 (0.88, 1.47) | 1.21 (1.03, 1.42)* | 1.52 (0.95, 2.46) | 0.12 (− 0.01, 0.25) | 0.06 (− 0.02, 0.15) |
| Fixed-effect | 1.04 (0.99, 1.10) | 1.11 (0.95, 1.30) | 1.24 (1.15, 1.33)* | 1.36 (1.06, 1.76)* | 0.09 (0.03, 0.16)* | 0.06 (− 0.00, 0.13) |
| SAH | 5 studies | 5 studies | 3 studies | 3 studies | 3 studies | 4 studies |
| Random-effects | 1.34 (1.14, 1.56)* | 1.89 (1.33, 2.70)* | 1.33 (1.03, 1.72)* | 1.86 (0.91, 3.77) | 0.40 (0.26, 0.53)* | 0.68 (0.05, 1.30)* |
| Fixed-effect | 1.31 (1.15, 1.48)* | 1.83 (1.33, 2.50)* | 1.32 (1.12, 1.54)* | 1.61 (1.04, 2.50)* | 0.40 (0.26, 0.53)* | 0.52 (0.39, 0.64)* |
| Post-CPB | 1 study | 1 study | – | – | 1 study | 1 study |
| Random-effects | 5.75 (0.35, 93.28) | 6.60 (0.37, 117.31) | – | – | 0.82 (0.18, 1.46)* | 0.72 (0.08, 1.36)* |
| Fixed-effect | 5.75 (0.35, 93.28) | 6.60 (0.37, 117.31) | – | – | 0.82 (0.18, 1.46)* | 0.72 (0.08, 1.36)* |
| Ischemic stroke | 1 study | 1 study | 1 study | 1 study | – | – |
| Random-effects | 1.41 (1.14, 1.74)* | 2.03 (1.29, 3.21)* | 1.47 (1.16, 1.85)* | 2.27 (1.22, 4.23)* | – | – |
| Fixed-effect | 1.41 (1.14, 1.74)* | 2.03 (1.29, 3.21)* | 1.47 (1.16, 1.85)* | 2.27 (1.22, 4.23)* | – | – |
Parameters in brackets are 95% CI
CA, cardiac arrest, CI, confidence interval, CPB, cardiopulmonary bypass, OR, odds ratio, PaO2, arterial partial pressure of oxygen, RR, relative risk, SAH, subarachnoid hemorrhage, SMD, standardized mean difference, TBI, traumatic brain injury
*Represent significant results