Table 3.
Care practices of the study population.
| Characteristic | 24–27 weeks n = 148) | 28–31 weeks (n = 1612) | 32–33 weeks (n = 2460) | 34–36 weeks (n = 9481) | Total (N = 13701) | F/χ2 | p |
|---|---|---|---|---|---|---|---|
| Pulmonary surfactant | 85 (57.4) | 658 (40.8) | 443 (18.0) | 307 (3.2) | 1493 (10.9) | 2517.415 | 0.000 |
| Any high-frequency ventilation or conventional ventilation | 83 (56.1) | 574 (35.6) | 379 (15.4) | 365 (3.8) | 1401 (10.2) | 1962.105 | 0.000 |
| Any nasal SIMV or CPAP therapy | 53 (35.8) | 780 (48.4) | 779 (31.7) | 871 (9.2) | 2483 (18.1) | 1840.568 | 0.000 |
| Nasal SIMV or CPAP therapy highest* | 12 (8.1) | 392 (24.3) | 521 (21.2) | 650 (6.9) | 1575 (11.5) | 689.484 | 0.000 |
*Highest level of support was defined for nasal SIMV as never used conventional for high-frequency ventilation but used nasal SIMV, and for CPAP as never used conventional or high-frequency ventilation or nasal SIMV but received CPAP therapy.