Table 4.

Area under curve for each predictive model shown in Table 3 and pairwise p-values for model comparisons of preterm birth (PTB)^*, very PTB^*, and late PTB^* in Black mothers^**

PTB
	Model 1	Model 2	Model 3	Model 4
Model 1	0.58
Model 2	0.09	0.62
Model 3	0.09	0.78	0.61
Model 4	0.002	0.05	0.02	0.65
Very PTB
	Model 1	Model 2	Model 3	Model 4
Model 1	0.57
Model 2	0.14	0.63
Model 3	0.06	0.62	0.61
Model 4	0.007	0.05	0.008	0.66
Late PTB
	Model 1	Model 2	Model 3	Model 4
Model 1	0.58
Model 2	0.08	0.61
Model 3	0.21	0.78	0.61
Model 4	0.004	0.05	0.02	0.66

Note:

^*PTB: preterm birth with gestational age <37 weeks; very PTB: preterm birth with gestational age <34 weeks; late PTB: preterm birth with gestational age 34.0–36.86 weeks.

^**Based on self-reported Black race.

^aThe values in the diagonal are the area under curve for each predictive model.

^bThe values in the off-diagonal are the p-values for testing the equality of the area under curve