Validation of Obstetric Estimate of Gestational Age on U.S. Birth Certificates.
ABSTRACT The birth certificate variable obstetric estimate of gestational age (OE) has not been previously validated against gestational age based on estimated date of delivery (EDD) from medical records.
We estimated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the corresponding 95% confidence intervals (CI) for preterm delivery (<37 weeks gestation) based on OE using EDD-based gestational age as the gold standard. Trained abstractors obtained the EDD from the prenatal record (64.8% in NYC, and 94.6% in Vermont), or, when not available, from the hospital delivery record for two population-based samples: 586 live births delivered in New York City (NYC) and 649 live births delivered in Vermont during 2009. Weights were applied to account for non-response and sampling design.
In NYC, the preterm delivery rate based on EDD was 9.7% (95 % CI 7.6-12.4) and 8.2% (6.3-10.6) based on OE; in Vermont, it was 6.8% (5.4-8.4) based on EDD and 6.3% (5.1-7.8) based on OE. In NYC, sensitivity of OE-based preterm delivery was 82.5% (69.4-90.8), specificity 98.1% (96.4-99.1), PPV 98.0% (95.2-99.2), and NPV 98.8% (95% CI 99.6-99.9). In Vermont, sensitivity of OE-based preterm delivery was 93.8% (81.8-98.1), specificity 99.6% (98.5-99.9), PPV 100%, and NPV 100%.
OE-based preterm delivery had excellent specificity, PPV and NPV. Sensitivity was moderate in NYC and excellent in VT. These results suggest OE-based preterm delivery from the birth certificate is useful for the surveillance of preterm delivery.
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ABSTRACT: Recent surveillance data suggest that mean birth weight has begun to decline in several developed countries. The aim of this study is to examine the changes in birth weight among singleton live births from 2002 to 2012 in Guangzhou, one of the most rapidly developed cities in China. We used data from the Guangzhou Perinatal Health Care and Delivery Surveillance System for 34108 and 54575 singleton live births with 28-41 weeks of gestation, who were born to local mothers, in 2002 and 2012, respectively. The trends in birth weight, small (SGA) and large (LGA) for gestational age and gestational length were explored in the overall population and gestational age subgroups. The mean birth weight decreased from 3162 g in 2002 to 3137 g in 2012 (crude mean difference, -25 g; 95% CI, -30 to -19). The adjusted change in mean birth weight appeared to be slight (-6 g from 2002 to 2012) after controlling for maternal age, gestational age, educational level, parity, newborn's gender and delivery mode. The percentages of SGA and LGA in 2012 were 0.6% and 1.5% lower than those in 2002, respectively. The mean gestational age dropped from 39.2 weeks in 2002 to 38.9 weeks in 2012. In the stratified analysis, we observed the changes in birth weight differed among gestational age groups. The mean birth weight decreased among very preterm births (28-31 weeks), while remained relatively stable among other gestational age subcategories. Among local population in Guangzhou from 2002 to 2012, birth weight appeared to slightly decrease. The percentage of SGA and LGA also simultaneously dropped, indicating that newborns might gain a healthier weight for gestational age.PLoS ONE 12/2014; 9(12):e115703. DOI:10.1371/journal.pone.0115703 · 3.53 Impact Factor
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ABSTRACT: We assessed the validity of selected items on the 2003 revised U.S. Standard Certificate of Live Birth to understand the accuracy of new and existing items. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of select variables reported on the birth certificate using the medical record as the gold standard for a representative sample of live births in New York City (n=603) and Vermont (n=664) in 2009. In both sites, sensitivity was excellent (>90%) for Medicaid coverage at delivery, any previous live births, and current method of delivery; sensitivity was moderate (70%-90%) for gestational diabetes; and sensitivity was poor (<70%) for premature rupture of the membranes and gestational hypertension. In both sites, PPV was excellent for Medicaid coverage, any previous live births, previous cesarean delivery, and current method of delivery, and poor for premature rupture of membranes. In both sites, almost all items had excellent (>90%) specificity and NPV. Further research is needed to determine how best to improve the quality of data on the birth certificate. Future revisions of the birth certificate may consider removing those items that have consistently proven difficult to report accurately.Public Health Reports 01/2015; 130(1):60-70. · 1.64 Impact Factor