TABLE 2.

Regression analysis summary

Dependent characteristic	Independent characteristics	Bivariate analysis (β ± SE)	Full model (β ± SE)
PhCI, mm Hg cm s	Preterm	27.7 ± 14.0*	33.1 ± 13.0*
	PMA, weeks	7.6 ± 3.0*	7.1 ± 2.9*
	Frequency, Hz	−5.8 ± 1.3**	−6.4 ± 1.3**
	Number of bursts, #	−2.3 ± 1.0*	−2.1 ± 1.0*
	UES nadir pressure, mm Hg	0.4 ± 0.1*	0.4 ± 0.1**

Note: Bivariate analysis used for selecting variables to construct the full model as well as the coefficient values from the full model. Bivariate analysis results show the exclusive relationship between each independent characteristic and PhCI. As all characteristics tested here showed a significant relationship with PhCI, all of them were used to construct the full model. PhCI is higher for preterm births and increases with PMA and UES nadir pressure but decreases when there is in an increase in number of bursts and pharyngeal contraction frequency.

^*P < 0.05,

^**P < 0.001.