Table 5.

Validity testing and odds ratios for an increasing Bishop Score and a decreasing Cervical Score at 26–29 weeks for SPTD <35 weeks’ gestation

	Bishop Score			Cervical Score
	≥5*	≥6	≥7	<1.5*	<1.0	<0
N (%) positive for test	199 (7.8)	71 (2.8)	19 (0.8)	147 (5.8)	59 (2.3)	14 (0.6)
Sensitivity %	32.1	17.9	7.1	35.7	23.8	6.0
95% CI	22.4–43.2	10.4–27.7	2.7–14.9	25.6–46.9	15.2–34.3	2.0–13.3
Specificity %	93.0	97.7	99.5	95.2	98.4	99.6
[False positive %]	[7.0]	[2.3]	[0.5]	[4.8]	[1.6]	[0.4]
Specificity 95% CI	91.9–94.0	97.0–98.2	99.1–99.7	94.3–96.0	97.8–98.9	99.3–99.8
Positive predictive value %	13.6	21.1	31.6	20.4	33.9	35.7
Adjusted+ Odds Ratio	4.4	5.7	6.6	8.2	13.5	5.6
95% CI	2.7–7.4	2.9–11.1	2.2–19.4	4.9–13.6	7.1–25.5	1.7–18.5
Area under ROC curve	0.68			0.68
95% CI	0.62–0.75			0.61–0.75

^*Selected diagnostic thresholds for SPTD <35 weeks at the 26–29 week examination

CI - confidence interval

⁺Adjusted for body mass index, black race, and previous preterm delivery.