Validation of Selected Items on the 2003 U.S. Standard Certificate of Live Birth: New York City and Vermont

ObjectiveWe 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.MethodsWe 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.ResultsIn 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.ConclusionFurther 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.The U.S. Standard Certificate of Live Birth serves as a legal document and a national and state data source for monitoring maternal and infant health. Assessments of the validity of items on the birth certificate can inform researchers and maternal and child health professionals on how best to use and interpret the birth certificate data for surveillance, public health practice, and research purposes. Previous validation studies of the 1989 version of the U.S. birth certificate documented high specificity for most items and high sensitivity or agreement for a limited number of items, including maternal demographics, delivery method, and infant birthweight, and low-to-moderate sensitivity or agreement for obstetric and medical risk factors.^1–5 The sensitivity of some items varied by maternal characteristics; indicators from birth certificates of infants born to Hispanic mothers and those not proficient in English had some of the lowest sensitivity estimates.⁴In 2003, a new revision of the U.S. Standard Certificate of Live Birth was released by the National Center for Health Statistics (NCHS) with some items from the 1989 revision and new items added. The revised certificate incorporated suggestions from a committee that included state vital registration staff, clinicians, medical and public health researchers, and representatives of national organizations. A criticism of the revised certificate is that it would have benefited from additional input from perinatal epidemiologists with clinical experience and that studies with large samples to assess reliability and validity were needed.⁶Since the release of the 2003 birth certificate, uptake of its use by states has been gradual; however, it was mandated that all jurisdictions adopt its use by 2014. Validation of new or revised items on the 2003 birth certificate has been limited, with few published studies. Studies include the examination of obstetric estimate of gestational age in California⁷ and two additional states;⁸ pre-pregnancy weight and height in Florida;⁹ Medicaid coverage for delivery in Iowa,¹⁰ California,¹¹ and two additional states;⁸ and gestational diabetes in several states.^5,8,12–15The most comprehensive evaluation of the 2003 birth certificate, conducted by NCHS, in a total of eight hospitals in two states, found wide variation in the quality of data by item and hospital. We sought to expand the current evidence of the validity of items on the 2003 birth certificate by conducting a validation study in two geographically and demographically distinct jurisdictions—New York City (NYC) and Vermont. We evaluated items that were less studied and for which the prevalence was sufficient and medical records could be considered a valid gold standard. We evaluated a combination of new, revised, and unchanged items.