Birth defects surveillance: Assessing the "gold standard"

Objectives. This study assessed the sensitivity of tbe Metropolitan Atlanta Congenital Defects Program (MACDP) by capitalizing on the delayed receipt of a data source. Methods. In 1997, we reviewed the medical records of potential eases from t he 1995 birth certificates that had not previously been identified by the M ACDP. Capture meth ods produced an estimate of total cases. Results. We identified 1149 infants with defects, including 20 exclusively from birth cv:certificates. The estimated sensitivity of the MACDP when dat a. fram birth certificates were included tvas 86.9% (95% confidence Interva l [CI] = 80.6%, 91.9%) at 1 year after birth, increasing to 94.8% (95% CI= 90.3%, 97.5%) at 2 years after birth. Conclusions. The MACDP under-estimates defects by 13% at 1 year after birth and by 5% at 2 years after birth.