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Table 2 Validity of birth certificate data compared to maternal interview in the Iowa health in pregnancy study

From: Validation of birth certificate and maternal recall of events in labor and delivery with medical records in the Iowa health in pregnancy study

Variable

Sensitivity (%)

Specificity (%)

PPV (%)

NPV (%)

True Positives (N)

False Positives (N)

False Negatives (N)

True Negatives (N)

Kappa

Low birthweight

95.8%

98.7%

94.0%

99.1%

437

28

19

2187

0.94

Preterm birth

99.6%

99.7%

99.2%

99.8%

755

6

3

1932

0.99

Post-term birth

98.9%

100.0%

100.0%

99.8%

260

0

3

1669

0.99

Pregnancy weight gain

99.2%

20.2%

97.6%

43.2%

2604

63

21

16

0.26

Vaginal delivery

99.1%

75.2%

91.6%

96.7%

1492

137

14

415

0.80

Smoking

10.6%

99.8%

90.2%

88.3%

37

4

313

2357

0.17

Alcohol use

34.6%

96.2%

8.2%

99.3%

9

101

17

2537

0.12

Race/ethnicity

 White

99.2%

91.7%

99.1%

92.4%

2347

22

20

244

0.91

 Black

90.8%

99.6%

93.2%

99.4%

138

10

14

2457

0.91

 Asian

91.9%

91.7%

97.9%

99.7%

91

2

8

2608

0.95

 Hispanic

67.6%

99.6%

82.0%

99.1%

50

24

24

2618

0.74

  1. Low birthweight was defined as infant weighing < 2500 g at birth. Preterm and post-term birth were defined as gestational age < 37 and ≥ 41 weeks gestation, respectively. Pregnancy weight gain was defined as an increase in maternal weight from the start of pregnancy through delivery; dichotomized as “yes” or “no”. Mode of delivery options were “vaginal” or “caesarean”