Reliability of birth defect data on birth certificates of Rio de Janeiro, Brazil, 2004

This study assessed the reliability of birth certificate data related to birth defects in Brazil's Live Birth Information System (SINASC). We selected 24 maternity hospitals in the Unified National Health System (SUS) and compared the reports of birth defects from birth certificates with medical records of mothers and live born infants in the city of Rio de Janeiro for the year 2004. After transposing the data to a specific form, the birth defects were coded by types and organ systems and compared to the SINASC data. The most commonly affected organs involved the central nervous and musculoskeletal systems. Agreement was more than 50% for the digestive, genitourinary, and musculoskeletal systems and chromosomal anomalies. Prevalence-adjusted kappa varied according to 2 or 3-digit ICD-10 analysis, with better results for the musculoskeletal, digestive, and genitourinary systems and congenital anomalies, and worse for the central nervous and cardio-circulatory systems, eye, neck, and ear malformations, and cleft lip and palate. The results were unsatisfactory, suggesting the need for more investments to train the persons responsible for completing birth certificates in maternity hospitals and develop a model for coding birth defects on these documents.