[Infant mortality rate in Cuiabá, Mato Grosso State, Brazil, 2005: a comparison between direct calculation and linkage between the live birth and infant mortality databases]

This study aimed to analyze the infant mortality rate (IMR) by linking the Live Birth Information System (SINASC) and the Mortality Information System (SIM) and comparing the result to direct calculation using crude data provided by the same databases. The systems used were SINASC, containing 9,590 certificates of live birth from January 1 to December 31, 2005, and SIM, containing 156 death certificates from the reference population (2005). Of the 156 deaths in the year 2005, 126 (80.8%) were paired by the direct method and 11 (7%) by manual search, totaling 137 deaths (87.8%). The rates found with the linkage method allowed calculating the real IMR (14.2 deaths/1,000 live births) and its components. The IMR using linkage was 17.3% lower than as calculated using crude SIM data. The early neonatal component (7.2 deaths/1,000 live births) accounted for half of the deaths in the first year of life (50.4%).