The NCHS pilot project to link birth and infant death records: stage 1

The National Center for Health Statistics (NCHS) has completed a pilot test of its method to develop national linked files of birth and infant death records. A linked file of the 1982 birth cohort was produced that successfully linked 97 percent of the death records for infants who died in a nine-State area. The method NCHS uses to create national linked files takes full advantage of two existing data sources: the NCHS fully coded natality and mortality files and State files of matched births and infant deaths. For the nine-State pilot area, NCHS obtained computerized linked files from the States and extracted from them the certificate numbers on matching birth and death records. With the use of these numbers, NCHS selected and linked birth and death statistical records from its final natality and mortality files, thus creating new statistical linked records. The initial match rate of 93.2 percent for the project's linked record file was increased to 96.7 percent as a result of efforts by the pilot States to complete the matching of birth and infant death records. Matching in the nine-State linked file appears to be highly accurate, based on the results of two evaluation studies. In the second stage of the project, now underway, NCHS will continue to evaluate and improve State and national linked files for the four birth cohorts of 1983-86. With funding from the Department of Health and Human Services' Office of the Assistant Secretary for Planning and Evaluation, stage 2 will be conducted in collaboration with each of the 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, and New York City, an independent registration area.