[Reliability of information on the underlying cause of death from external causes in people under 18 years of age in the Municipality of Duque de Caxias, Rio de Janeiro, Brazil].

This study assesses the quality of official data on mortality due to external causes. It examines the agreement in the underlying cause of death by accidents and violence in children and adolescents under 18 years of age in the Municipality of Duque de Caxias, Rio de Janeiro State. Codings based on death certificates (DC) issued by the Institute of Forensic Medicine - IFM (ICDifm) and those complemented by the Municipal Secretariat of Health - MSH (ICDmsh) are compared to the coding directly obtained from autopsy logs and attached to police reports accessible at the IFM (ICDresearch). Levels of agreement (kappa) between ICDmsh/ICDifm, ICDresearch/ ICDifm, and ICDresearch/ICDmsh were 0.33, 0.26, and 0.81, respectively, in 1995 and 0.26, 0.22, and 0.71 in 1996. When analyzed together, all three sources agreed by 45% and 37.6% in the respective years. ICDresearch and ICDmsh agreed among themselves and disagreed with ICDifm by 46.9% in 1995 and 48.2% in 1996. Results show that the IFM fails to transfer available information to the MSH via DCs. Although a satisfactory updating is subsequently carried out at the MSH, the relevance and legality of this procedure should be called into question and further discussed.