Table 3

Baseline characteristics and outcomes of participants on non-invasive respiratory support, invasive ventilation with TA Ureaplasma-negative specimens and invasive ventilation with TA Ureaplasma-positive specimens

OutcomeNo. (%) of participants*P value†
Never intubated
(no TA specimen)
(n=47)
TA Ureaplasma negative
(n=52)
TA Ureaplasma positive
(n=21)
Baseline characteristics
Male, n (%)24 (51)25 (48)9 (43)0.88
Non-white race, n (%)34 (72)24 (46)12 (57)0.12
Birth weight, mean (SD), g994 (244)854 (207)805 (188)0.004
Gestational age, mean (SD), weeks26.9 (1.2)26.0 (1.4)25.4 (1.0)<0.001
Gestational age strata, n (%)
 240–266 weeks24 (51)39 (75)19 (90)0.004
 270–286 weeks23 (48)13 (25)2 (10)
Preterm labour, n (%)37 (79)40 (77)18 (86)0.62
PPROM23 (49)16 (31)13 (62)0.03
Antenatal steroids39 (83)42 (81)17 (81)0.95
Maternal macrolide exposure20 (43)13 (25)6 (29)0.26
C/S delivery28 (60)29 (56)9 (43)0.40
Admission WCC × 103, mean (SD)14.5 (9.4)11.3 (7.2)21.4 (17.8)0.05
Ureaplasma spp. respiratory colonisation, n (%)18 (38)5 (10)21 (100)0.01
Primary and secondary outcomes
Ureaplasma-free survival, n (%)37 (78)46 (88)8 (38)0.002
Survival, n (%)47 (100)47 (90)15 (71)<0.001
Ureaplasma clearance post-treatment, n (%)8/18 (44)4/5 (8%)11/21 (52)0.44
Survival free of physiological BPD, n (%)‡37/45 (82)22/51 (43)7 (33)<0.001
Physiological BPD, n (%)‡§8/45 (18)26/48 (54)9/16 (56)0.001
Modified Shennan BPD, n (%)§14 (29)28/49 (57)9/16 (56)0.02
Moderate-severe BPD, n (%)§14 (29)30/49 (61)9/16 (56)0.009
Discharge home, n (%)33 (70)28 (54)7 (33)0.02
Postnatal steroids exposure, n (%)3 (6)16 (31)10 (48)0.001
Passed hearing screen, n (%)¶44/46 (96)45/46 (98)12/15 (80)0.27
Total duration IMV, median (IQR)¶**1 (1–2)19.5 (9.5–55)44 (24 to –)<0.001
Total duration supplemental oxygen, median (IQR)‡**38 (15–64)85 (59–125)135 (77 to –)<0.001
Duration hospitalisation, median (IQR)¶**71 (56–87)99 (81–142)110 (76 to –)<0.001
  • *One surviving participant with moderate-severe BPD who was discharged home was intubated but had no TA specimens and is not included in this analysis.

  • †P values for binary outcomes are based on a score test from generalised estimating equations to account for correlations between twins, or Fisher’s exact test when one of the cell sizes has an expectation of less than 5. P values for quantitative outcomes are based on non-parametric tests using multiple outputation to account for correlations between twins.

  • ‡Excludes three participants who could not be classified with respect to physiological BPD.

  • §Excludes eight participants who died prior to BPD assessment.

  • ¶Based on only those who survived until discharge but excludes two survivors who did not have a hearing screen.

  • **In computing the median and IQR, those who died are included as having the worst outcomes. For the TA Ureaplasma-positive participants, more than 25% died, so it was not possible to specify the actual 75th percentile.

  • BPD, bronchopulmonary dysplasia; C/S, caesarean section; IMV, intermittent mandatory ventilation; PPROM, preterm premature rupture of membranes; TA, tracheal aspirate; WCC, white cell count.