Table 2. Validation of the DAD maternal and neonatal categorical baseline variables.

	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	Kappa coefficient (95% CI)
Maternal baseline variables
Smoking during pregnancy (N=1449)	0.75 (0.70,0.81)	0.92 (0.91,0.94)	0.68 (0.63,0.73)	0.94 (0.93,0.96)	0.65 (0.60,0.70)
Substance use during pregnancy (N=1449)	0.22 (0.13,0.31)	0.98 (0.97,0.99)	0.38 (0.25,0.51)	0.95 (0.94,0.96)	0.25 (0.15,0.35)
Pre-gestational hypertension (N=1368)	0.30 (0.20,0.41)	0.99 (0.99,1.00)	0.68 (0.52,0.84)	0.96 (0.95,0.97)	0.40 (0.28,0.51)
Gestational hypertension (N=1368)	0.40 (0.34,0.47)	0.98 (0.98,0.99)	0.83 (0.77,0.90)	0.89 (0.87,0.90)	0.49 (0.42,0.55)
Pre-gestational diabetes (N=1368)	1.00 (1.00,1.00)	0.23 (0.20,0.25)	0.09 (0.07,0.10)	1.00 (1.00,1.00)	0.04 (0.03,0.05)
Gestational diabetes (N=1368)	0.19 (0.12,0.26)	0.82 (0.80,0.84)	0.10 (0.06,0.14)	0.91 (0.89,0.92)	0.01 (0.00,0.06)
Placenta previa (N=626)	0.89 (0.68,1.00)	0.95 (0.93,0.97)	0.20 (0.07,0.33)	1.00 (1.00,1.00)	0.32 (0.15,0.49)
Placental abruption (N=626)	0.76 (0.56,0.97)	0.91 (0.89,0.93)	0.19 (0.10,0.28)	0.99 (0.99,1.00)	0.27 (0.15,0.39)
PPROM (N=786)	0.84 (0.78,0.91)	0.77 (0.74,0.80)	0.44 (0.38,0.50)	0.96 (0.94,0.98)	0.45 (0.38,0.52)
Cervical insufficiency (N=635)	0.85 (0.65,1.00)	0.96 (0.95,0.98)	0.32 (0.17,0.48)	1.00 (0.99,1.00)	0.45 (0.27,0.63)
Chorioamnionitis (N=635)	0.39 (0.24,0.55)	0.98 (0.97,0.99)	0.58 (0.39,0.77)	0.97 (0.95,0.98)	0.44 (0.29,0.60)
Multiples (N=2001)	0.95 (0.93,0.97)	1.00 (0.99,1.00)	0.99 (0.98,1.00)	0.99 (0.98,0.99)	0.96 (0.95,0.97)
Neonatal baseline variables
Sex (N=2078)	0.99 (0.99,1.00)	1.00 (0.99,1.00)	0.99 (0.99,1.00)	0.99 (0.99,1.00)	0.99 (0.98,0.99)
Small for gestational age (N=1417)	0.87 (0.81,0.93)	0.99 (0.98,0.99)	0.88 (0.82,0.94)	0.99 (0.98,0.99)	0.86 (0.81,0.91)

DAD, Discharge Abstract Database; PPV, Positive predictive value; NPV, Negative predictive value; PPROM, Preterm premature rupture of membranes.