Infant mortality was defined as death during the first year of
life. Neonatal and postneonatal mortality were defined as infant
deaths within and after the first 28 days of life, respectively.
Causes of death were categorised into 11 groups according to
ICD codes (appendix A of online data supplement): congenital
anomalies, birth asphyxia, other neonatal morbidities
(non-asphyxia), sudden infant death syndrome (SIDS),
infections, cardiovascular and pulmonary causes, endocrine and
metabolic disorders, neuromuscular disorders, malignant
neoplasms, external causes of deaths, and other causes.