Neonatal mortality by gestational age and birth weight in Italy, 1998-2003: a record linkage study

Neonatal mortality rates by gestational age and birth weight category are important indicators of maternal and child health and care quality. However, due to recent laws on administrative simplification and privacy, these specific rates have not been calculated in Italy since 1999. The main aim of this work is to assess the possibility of retrieving information on neonatal mortality by the linkage between records related to live births and records related to infant deaths within the first month of life, with reference to 2003 and 2004 birth cohorts. From a strict methodological point of view, some critical aspects of the most used record linkage approach are highlighted: specific problems may arise from the choice of records to be linked if there are consistency constraints between pairs (in this context, one death record can be linked to at most one birth record). In the light of considerations on the quality of the starting data, the retrieval of information on neonatal mortality by gestational age and birth weight is restricted to Northern Italy. Specific neonatal mortality rates are provided with reference to 2003 and discussed with particular emphasis on quality issues in the data collection processes.