Method of linking Medicaid records to birth certificates may affect infant outcome statistics

Objectives. This study assessed how different methods of matching Medicaid records to birth certificates affect Medicaid infant outcome statistics. Methods. Claims paid by Medicaid for hospitalization of the newborn and for the mother's delivery were matched separately to 1995 North Carolina live birth certificates. Results. Infant mortality and low-birthweight rates were consistently lower when Medicaid was defined by a matching newborn hospitalization record than when results were based on a matching Medicaid delivery record. Conclusions. Studies of birth outcomes in the Medicaid population may have variable results depending on the method of matching that is used to identify Medicaid births.