Table 5 Neurological outcomes at 2 years.
| Outcome | HFOV | CV | Relative risk or difference in means | 95% CI |
|---|---|---|---|---|
| Neuromotor | ||||
| No head control | 0/170 (0%) | 1/189 (1%) | * | |
| Poor head control | 0/170 (0%) | 0/189 (0%) | ||
| Normal head control | 170/170 (100%) | 188/189 (99%) | ||
| Unable to sit unsupported | 3/168 (2%) | 1/185 (1%) | 1.47 | 0.33 to 6.46 |
| Sits unsupported, less well than others | 1/168 (1%) | 2/185 (1%) | ||
| Sits unsupported | 164/168 (98%) | 182/185 (98%) | ||
| Unable to stand | 5/168 (3%) | 7/189 (4%) | 0.96 | 0.46 to 2.03 |
| Requires support to rise, stands | 7/168 (4%) | 7/189 (4%) | ||
| Stands in one movement | 156/168 (93%) | 175/189 (93%) | ||
| Unable to walk | 11/169 (7%) | 14/190 (7%) | 0.78 | 0.43 to 1.43 |
| Walks, non‐fluent gait | 5/169 (3%) | 9/190 (5%) | ||
| Walks normally | 153/169 (91%) | 167/190 (88%) | ||
| Unable to use left hand | 3/165 (2%) | 1/179 (1%) | 1.55 | 0.60 to 3.98 |
| Picks up with left hand not pincer grip | 7/165 (4%) | 6/179 (3%) | ||
| Picks up with left hand, pincer grip | 155/165 (94%) | 172/179 (96%) | ||
| Unable to use right hand | 1/167 (1%) | 2/185 (1%) | 1.11 | 0.36 to 3.37 |
| Picks up with right hand not pincer grip | 5/167 (3%) | 4/185 (2%) | ||
| Picks up with right hand, pincer grip | 161/167 (96%) | 179/185 (97%) | ||
| Unable to do bimanual tasks | 5/168 (3%) | 1/188 (1%) | 2.24 | 0.93 to 5.41 |
| Difficulty using both hands together | 9/168 (5%) | 6/188 (3%) | ||
| Uses both hands well | 154/168 (92%) | 181/188 (96%) | ||
| ⩾1convulsion/month on treatment | 1/167 (1%) | 0/189 (0%) | 2.64 | 1.04 to 6.72 |
| <1/month on treatment | 3/167 (2%) | 0/189 (0%) | ||
| Convulsions, no treatment | 10/167 (6%) | 6/189 (3%) | ||
| No convulsions | 153/167 (92%) | 183/189 (97%) | ||
| Vision | ||||
| Squint | 22/171 (13%) | 23/189 (12%) | 1.06 | 0.61 to 1.83 |
| Parental report of visual problems; reduced vision | 5/163 (3%) | 14/189 (7%) | 0.41 | 0.15 to 1.12 |
| Abnormal eye movements | 8/165 (5%) | 7/188 (4%) | 1.30 | 0.48 to 3.51 |
| Hearing | ||||
| Profound hearing loss despite aids | 2/170 (1%) | 0/188 (0%) | 0.81 | 0.38 to 1.72 |
| Hearing loss helped by aids | 3/170 (2%) | 2/188 (1%) | ||
| Hearing loss not severe enough for aids | 3/170 (2%) | 10/188 (5%) | ||
| Suspected hearing loss | 3/170 (2%) | 3/188 (2%) | ||
| No hearing loss | 159/170 (94%) | 173/188 (92%) | ||
| Other domains | ||||
| Does not understand signs or words | 3/168 (2%) | 0/185 (0%) | * | |
| Tube feeding | 1/172 (1%) | 4/191 (2%) | 0.28 | 0.03 to 2.46 |
| Disability grading | ||||
| Overall | ||||
| Severe disability | 15/172 (9%) | 16/191 (8%) | 0.93 | 0.74 to 1.16 |
| Other disability | 62/172 (36%) | 76/191 (40%) | ||
| No disability | 95/172 (55%) | 99/191 (52%) | ||
| 23–25 weeks gestation | ||||
| Severe disability | 5/51 (10%) | 4/47 (9%) | 0.88 | 0.60 to 1.31 |
| Other disability | 19/51 (37%) | 21/47 (45%) | ||
| No disability | 27/51 (53%) | 22/47 (47%) | ||
| 26–28 weeks gestation | ||||
| Severe disability | 10/121 (8%) | 12/144 (8%) | 0.94 | 0.72 to 1.23 |
| Other disability | 43/121 (36%) | 55/144 (38%) | ||
| No disability | 68/121 (56%) | 77/144 (53%) | ||
| Cognitive development | ||||
| Parent report composite score <49† | 41/137 (30%) | 40/151 (26%) | 1.13 | 0.78 to 1.63 |
| Parent report composite | 75 (38) | 76 (37) | −1.7 | −10.4 to 7.0 |
| Growth | ||||
| 23–25 weeks gestation | ||||
| Height SDS | −0.76 (1.03) | −0.67 (0.98) | −0.09 | −0.50 to 0.33 |
| Weight SDS | −0.90 (1.16) | −0.80 (1.41) | −0.10 | −0.63 to 0.43 |
| Head circumference SDS | −1.46 (1.28) | −1.59 (1.44) | 0.13 | −0.45 to 0.70 |
| 26–28 weeks gestation | ||||
| Height SDS | −0.40 (1.09) | −0.53 (1.10) | 0.13 | −0.16 to 0.42 |
| Weight SDS | −0.54 (1.26) | −0.73 (1.24) | 0.19 | −0.13 to 0.51 |
| Head circumference SDS | −1.14 (1.42) | −1.28 (1.50) | 0.15 | −0.25 to 0.54 |
Values are number/total (%) or mean (SD). Relative risk is the ratio of the risk of any adverse outcome in the two groups. Severe disability is at least one extreme response in one of the following clinical domains: neuromotor, vision, hearing, communication, or other physical disabilities. No disability is a normal (or missing) response to all clinical domains.
*Impossible to calculate as one group has no adverse outcomes.
†Parental questionnaire composite score of non‐verbal development, sentence complexity, and vocabulary; 49 is the cut off for cognitive delay equivalent to Bayley mental development index ⩽70.16
HFOV, High frequency oscillatory ventilation; CV, conventional ventilation; SDS, standard deviation score.17