Comparison of crude and adjusted mortality rates from leading causes of death in northeastern Brazil

Objective: To present how the adjustment of incompleteness and misclassification of causes of death in the vital registration (VR) system can contribute to more accurate estimates of the risk of mortality from leading causes of death in northeastern Brazil. Methods: After estimating the total numbers of deaths by age and sex in Brazil's Northeast region in 2002-2004 by correcting for undercount in the VR data, adjustment algorithms were applied to the reported cause-of-death structure. Average anual age-standardized mortality rates were computed by cause, with and without the corrections, and compared to death rates for Brazil's South region after adjustments for potential misdiagnosis. Results: Death rates from ischemic heart disease, lower respiratory infections, chronic obstructive pulmonary disease, and perinatal conditions were more than 100% higher for both sexes than what was suggested by the routine VR data. Corrected cause-specific mortality rates were higher in the Northeast region versus the South region for the majority of causes of death, including several noncommunicable conditions. Conclusions: Failure to adjust VR data for undercount of cases reported and misdiagnoses will cause underestimation of mortality risks for the populations of the Northeast region, which are more vulnerable than those in other regions of the country. In order to more reliably understand the pattern of disease, all cause-specific mortality rates in poor populations should be adjusted.