Table 2

Cross-classified hierarchical models of factors significantly associated with proportion of time in target range, and proportion of time with saturation 98–100%

Target range98–100%
CoefficientSEp ValueCoefficientSEp Value
Adjusted overall mean0.1630.032<0.0010.2680.039<0.001
Postmenstrual ages, per week−0.0200.002<0.0010.0430.003<0.001
Fraction of inspired oxygen >0.5 compared with <0.50.0390.0200.0470.1740.032<0.001
Nurse:patient ratio*0.0280.0270.293−0.0300.0160.057
High-frequency oscillator ventilation, nurse caring for one patient0.1280.034<0.001Reference group: all monitoring periods on high-frequency oscillator ventilation
Nurse caring for two or more patients−0.0820.0360.021
Synchronised intermittent mandatory ventilation−0.0410.0180.0170.1120.026<0.001
Continuous positive airway pressure0.0180.0120.1120.0050.0250.829
Nasal cannula, nurse caring for two patientsReference group: all monitoring periods on nasal cannula−0.020.0350.566
Nurse caring for three or more patients0.0620.0240.011
  • * Nurse:patient ratio term defined differently for the two models. See text.