Intraventricular haemorrhage grade 3 and 4: high frequency ventilation (HFV) versus conventional ventilation (CV)
| Reference | HFV event observed/ total No of patients | CV event observed/ total No of patients | Relative risk (95% CI) |
|---|---|---|---|
| HIFI, 1989 | 84/327 | 63/346 | 1.41 (1.06, 1.88) |
| Clark, 1992 | 6/30 | 6/26 | 0.87 (0.32, 2.36) |
| Ogawa, 1993 | 2/46 | 1/46 | 2.00 (0.19, 21.30) |
| Gerstmann, 1996 | 2/56 | 6/55 | 0.33 (0.07, 1.55) |
| Wiswell, 1996 | 15/37 | 8/36 | 1.82 (0.88, 3.77) |
| Keszler, 1997 | 9/61 | 9/59 | 0.97 (0.41, 2.27) |
| Rettwitz-Volk, 1998 | 5/46 | 2/50 | 2.82 (0.55, 13.33) |
| Plavka (in press) | 0/21 | 1/20 | 0.32 (0.01, 7.38) |
| Total for all studies | 123/624 | 96/638 | 1.31 (1.04, 1.66) |
| Total for HLVS subgroup | 19/214 | 23/206 | 0.78 (0.45, 1.37) |
| Total for surfactant subgroup | 33/267 | 27/266 | 1.20 (0.76, 1.90) |
| Total for HFOV subgroup | 99/526 | 79/543 | 1.30 (1.00, 1.69) |
| Total for HFJV subgroup | 24/98 | 17/95 | 1.37 (0.79, 2.37) |
HFV=high frequency ventilation; HFOV=high frequency oscillatory ventilation; HFJV=high frequency jet ventilation; CV=conventional ventilation; RDS=respiratory distress syndrome; BPD=bronchopulmonary dysplasia; CLD=chronic lung disease; HLVS=high lung volume strategy; RR=relative risk; CI=confidence interval.