Table 3.
Comparisons of outcomes for infants treated with less invasive surfactant administration (LISA) and the rest of the infants (non-LISA) before (panel 1) and after (panel 2) propensity score matching, and for LISA infants and infants who received their initial dose of surfactant after endotracheal intubation (non-LISA+S, panel 3) after propensity score matching
| Panel 1: Original data | Panel 2: Propensity score subset* | Panel 3: Propensity score subset*, only infants who received surfactant | |||||||||||||
| LISA | Non-LISA | Diff. | 95% CI | P value | LISA | Non-LISA | Diff. | 95% CI | P value | LISA | Non-LISA+S | Diff. | 95% CI | P value | |
| Number of infants | 222 | 621 | – | – | – | 198 | 198 | – | – | – | 146 | 146 | – | – | – |
| Survived to 7 days, % | 99% | 91% | −8% | −10% to −5% | <0.001 | 98% | 93% | −6% | −10% to −2% | 0.006 | 98% | 97% | −1% | −4% to 3% | 0.70 |
| Survived to PMA 36, % | 94% | 86% | −8% | −13% to −4% | <0.001 | 94% | 88% | −6% | −11% to 0% | 0.05 | 95% | 91% | −3% | −9% to 2% | 0.26 |
| Survived to PMA 40, % | 94% | 85% | −8% | −13% to −4% | 0.001 | 93% | 88% | −6% | −11% to 0% | 0.06 | 94% | 91% | −3% | −9% to 3% | 0.38 |
| Survived without BPD at PM 36, % | 54% | 42% | −12% | −19% to −4% | 0.002 | 54% | 49% | −5% | −14% to 5% | 0.37 | 54% | 48% | −6% | −18% to 5% | 0.29 |
| Survived without BPD at PM 40, % | 82% | 71% | −10% | −16% to −4% | 0.003 | 81% | 78% | −4% | −11% to 4% | 0.38 | 82% | 79% | −2% | −11% to 7% | 0.66 |
| BPD-36†, % | 42% | 50% | 9% | 1% to 17% | 0.03 | 42% | 42% | 0% | −10% to 10% | 0.97 | 42% | 47% | 5% | −6% to 17% | 0.38 |
| BPD-40†, % | 12% | 16% | 4% | −1% to 9% | 0.17 | 12% | 14% | 2% | −5% to 9% | 0.59 | 12% | 13% | 0% | −8% to 8% | 0.93 |
| ICH/PVL, % | 8% | 10% | 2% | −2% to 6% | 0.34 | 8% | 11% | 4% | −2% to 9% | 0.23 | 7% | 12% | 5% | −1% to 12% | 0.11 |
| NEC, % | 5% | 5% | 0% | −4% to 3% | 0.79 | 5% | 4% | −1% | −5% to 3% | 0.61 | 4% | 3% | −1% | −5% to 4% | 0.76 |
| MV, % | 62% | 81% | 19% | 12% to 26% | <0.001 | 61% | 78% | 17% | 8% to 26% | <0.001 | 64% | 97% | 34% | 25% to 42% | <0.001 |
| MV, all infants, days‡, mean | 8.3 | 11.3 | 3.0 | 0.8 to 5.2 | 0.007 | 8.4 | 12.6 | 4.1 | 0.0 to 8.2 | 0.05 | 8.9 | 14.7 | 5.8 | 0.6 to 10.9 | 0.03 |
| MV, all infants, days‡, median | 3 | 5 | 2 | – | – | 3 | 4 | 1 | – | – | 4 | 7 | 3 | – | – |
| MV, survived to PMA 36, days‡, mean | 8.2 | 11.6 | 3.4 | 1.0 to 5.8 | 0.005 | 8.3 | 12.4 | 4.1 | −0.4 to 8.6 | 0.07 | 8.8 | 14.3 | 5.5 | 0.0 to 11 | 0.05 |
| Diff. in MV days‡, after adjustment* | – | – | 3.5 | 0.6 to 0.02 | 0.02 | – | – | 4.1 | 0.3 to 8 | 0.04 | – | – | 5.8 | 0.8 to 10.8 | 0.02 |
Gestational age 25–27 weeks (n=843).
*Infants with missing data in adjustment variables are not included.
†Only infants who survived to PMA 36/PMA 40.
‡Also includes infants with zero days on MV.
BPD-36 and BPD-40, supplemental oxygen or positive respiratory support at 36 and 40 weeks’ PMA; Diff., difference; ICH/PVL, intracranial haemorrhage/cystic periventricular leukomalacia; MV, mechanical ventilation; NEC, necrotising enterocolitis; PMA, postmenstrual age.