Trends in dermatomyositis- and polymyositis-related mortality in the state of São Paulo, Brazil, 1985-2007: multiple cause-of-death analysis.

BACKGROUND: Dermatomyositis (DM) and polymyositis (PM) are rare systemic autoimmune rheumatic diseases with high fatality rates. There have been few population-based mortality studies of dermatomyositis and polymyositis in the world, and none have been conducted in Brazil. The objective of the present study was to employ multiple-cause-of-death methodology in the analysis of trends in mortality related to dermatomyositis and polymyositis in the state of São Paulo, Brazil, between 1985 and 2007. METHODS: We analyzed mortality data from the São Paulo State Data Analysis System, selecting all death certificates on which DM or PM was listed as a cause of death. The variables sex, age and underlying, associated or total mentions of causes of death were studied using mortality rates, proportions and historical trends. Statistical analysis were performed by chi-square and H Kruskal-Wallis tests, variance analysis and linear regression. A p value less than 0.05 was regarded as significant. RESULTS: Over a 23-year period, there were 318 DM-related deaths and 316 PM-related deaths. Overall, DM/PM was designated as an underlying cause in 55.2% and as an associated cause in 44.8%; among 634 total deaths females accounted for 71.5%. During the study period, age- and gender-adjusted DM mortality rates did not change significantly, although PM as an underlying cause and total mentions of PM trended lower (p < 0.05). The mean ages at death were 47.76 ± 20.81 years for DM and 54.24 ± 17.94 years for PM (p = 0.0003). For DM/PM, respectively, as underlying causes, the principal associated causes of death were as follows: pneumonia (in 43.8%/33.5%); respiratory failure (in 34.4%/32.3%); interstitial pulmonary diseases and other pulmonary conditions (in 28.9%/17.6%); and septicemia (in 22.8%/15.9%). For DM/PM, respectively, as associated causes, the following were the principal underlying causes of death: respiratory disorders (in 28.3%/26.0%); circulatory disorders (in 17.4%/20.5%); neoplasms (in 16.7%/13.7%); infectious and parasitic diseases (in 11.6%/9.6%); and gastrointestinal disorders (in 8.0%/4.8%). Of the 318 DM-related deaths, 36 involved neoplasms, compared with 20 of the 316 PM-related deaths (p = 0.03). CONCLUSIONS: Our study using multiple cause of deaths found that DM/PM were identified as the underlying cause of death in only 55.2% of the deaths, indicating that both diseases were underestimated in the primary mortality statistics. We observed a predominance of deaths in women and in older individuals, as well as a trend toward stability in the mortality rates. We have confirmed that the risk of death is greater when either disease is accompanied by neoplasm, albeit to lesser degree in individuals with PM. The investigation of the underlying and associated causes of death related to DM/PM broaden the knowledge of the natural history of both diseases and could help integrate mortality data for use in the evaluation of control measures for DM/PM.

Comparative evaluation of underlying causes of death processed by the Automated Classification of Medical Entities and the Underlying Cause of Death Selection Systems

A identificaçäo correta da causa básica de morte e atribuiçäo de código preciso da Classificaçäo Internacional de Doença à mesma säo importantes para a obtençäo de estatísticas da mortalidade confiáveis e passíveis de comparabilidade universal. Estes fatores, dentre outros, levaram ao desenvolvimento de programas de computador para identificar automaticamente a causa básica de morte. Este trabalho teve a finalidade de comparar a causa básica de morte identificada respectivamente pelos programas Automed Classification of Medical Entities (ACME) e pelo Sistema de Seleçäo de Causa Básica de Morte (SCB). O arquivo para a entrada de dados sobre causas de morte (input file) para o Sistema ACME contendo registros de 129.104 declaraçöes de óbito de mortes ocorridas no estado de Säo Paulo de junho a dezembro de 1993 foi utilizado para o processamento da causa básica pelo SCB. Os problemas identificados pelo processamento dos registros do mês de junho foram considerados para o aprimoramento do sistema SCB. Foram encontradas 3.278 causas básicas de morte identificadas de modo diferente pelos problemas ACME e SCB. Essas diferenças foram atribuídas à falta de resposta adequada a janelas de diálogo durante o processamento pelo SCB, a óbitos por doenças devida a vírus da imunodeficiência adquirida para os quais näo havia tabelas de decisäo específicas, a erros de codificaçäo e/ou digitaçäo e a problemas propriamente ditos. A análise pormenorizada destes últimos mostrou que, em sua maioria, as causas básicas processadas pelo sistema SCB estavam corretas, que diferentes interpretaçöes das regras de mortalidade foram dadas pelos sistemas comparados, que alguns problemas particulares näo tiveram explicaçäo adequada por falta de documentaçäo sobre os mesmos e que uma menor proporçäo de problemas consistia de erros do SCB. O número pequeno e praticamente insignificante de problemas encontrados garante o uso da versäo do SCB para a Nona Revisäo da Classificaçäo Internacional de Doenças e assegura a continuidade dos trabalhos relativos à sua versäo para a Décima Revisäo