Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination.

BACKGROUND: In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases. METHODS: A comparison of two control groups in a case control study of the efficacy of BCG revaccination. One group was selected from subjects presenting to the heath unit the case attended for routine prevention and care; the second group was selected from the neighbourhood of cases. All Health Units from which controls were selected offered BCG revaccination. Efficacy estimated in a randomized control trial of BCG revaccination was used to establish that the neighbourhood control group was the one that gave unbiased results. RESULTS: The proportion of controls with scars indicating BCG revaccination was higher among the control group selected from Health Unit attenders than among neighbourhood controls. This excess was not removed after control for social variables and history of exposure to tuberculosis, and appears to have resulted from the fact that people attending the Health Unit were more likely to have been revaccinated than neighbourhood controls, although we can not exclude an effect of other unmeasured variables. CONCLUSION: In this study, controls selected from people presenting to a Health Unit overrepresented exposure to BCG revaccination. Had the results from the HU attenders control group been accepted this would have resulted in overestimation of vaccine efficacy. When the exposure of interest is offered in a health facility, selection of controls from attenders at the facility may result in over representation of exposure in controls and selection bias

Uso do linkage para a melhoria da completude do SIM e do Sinasc nas capitais brasileiras

OBJETIVO: Analisar a contribuição do linkage entre os bancos de dados de nascidos vivos e óbitos infantis para a melhoria da completude das variáveis comuns ao Sistema de Informações sobre Mortalidade (SIM) e ao Sistema de Informação sobre Nascidos Vivos (Sinasc) nas capitais brasileiras no ano de 2012. MÉTODOS: Foram estudados 9.001 óbitos de menores de um ano registrados no SIM no ano de 2012 e 1.424.691 nascidos vivos em 2011 e 2012 contidos no Sinasc. As bases de dados foram relacionadas por meio do linkage em duas etapas – determinística e probabilística. Calculou-se o percentual de incompletude das variáveis comuns ao SIM e ao Sinasc antes e após o emprego da técnica. RESULTADOS: Foi possível relacionar 90,8% dos óbitos à sua respectiva declaração de nascido vivo, a maioria pareada deterministicamente. Constatou-se maior percentual de pares em Porto Alegre, Curitiba e Campo Grande. Nas capitais do Norte, a média de pares foi de 84,2%; no Sul, esse resultado chegou a 97,9%. As 11 variáveis comuns ao SIM e ao Sinasc apresentavam 11.278 campos incompletos cumulativamente, sendo possível recuperar 91,4% das informações após o emprego do linkage. Cinco variáveis apresentavam completude excelente no Sinasc em todas as capitais brasileiras e apenas uma no SIM antes do relacionamento. Após a aplicação dessa técnica, todas as 11 variáveis do Sinasc passaram ao status de excelência, enquanto o mesmo ocorreu em sete no SIM. A capital de nascimento associou-se significativamente ao componente do óbito na qualidade da informação. CONCLUSÕES: Apesar dos avanços na cobertura e qualidade do SIM e do Sinasc, ainda são identificados problemas de completude das variáveis, em especial no SIM. Nessa perspectiva, o emprego do linkage apresenta-se como estratégia para qualificação de informações importantes para análise das mortes infantis.OBJECTIVE: To analyze the contribution of linkage between databases of live births and infant mortality to improve the completeness of the variables common to the Mortality Information System (SIM) and the Live Birth Information System (SINASC) in Brazilian capitals in 2012. METHODS: We studied 9,001 deaths of children under one year registered in the SIM in 2012 and 1,424,691 live births present in the SINASC in 2011 and 2012. The databases were related with linkage in two steps – deterministic and probabilistic. We calculated the percentage of incompleteness of the variables common to the SIM and SINASC before and after using the technique. RESULTS: We could relate 90.8% of the deaths to their respective declarations of live birth, most of them paired deterministically. We found a higher percentage of pairs in Porto Alegre, Curitiba, and Campo Grande. In the capitals of the North region, the average of pairs was 84.2%; in the South region, this result reached 97.9%. The 11 variables common to the SIM and SINASC had 11,278 incomplete fields cumulatively, and we could recover 91.4% of the data after linkage. Before linkage, five variables presented excellent completeness in the SINASC in all Brazilian capitals, but only one variable had the same status in the SIM. After applying this technique, all 11 variables of the SINASC became excellent, while this occurred in seven variables of the SIM. The city of birth was significantly associated with the death component in the quality of the information. CONCLUSIONS: Despite advances in the coverage and quality of the SIM and SINASC, problems in the completeness of the variables can still be identified, especially in the SIM. In this perspective, linkage can be used to qualify important information for the analysis of infant mortality

A Estratégia Saúde da Família no Estado de Pernambuco: avaliação do processo de trabalho das equipes por porte populacional

O estudo teve como objetivo avaliar o processo de trabalho das equipes de saúde da família do Estado de Pernambuco, por porte populacional, no ano de 2009. Foram aplicados questionários estruturados a 154 equipes de 24 municípios e avaliados itens referentes à organização da equipe, articulação com a comunidade e a programas específicos. Os resultados mostraram que as equipes dos municípios de maior porte se destacaram-se dos demais quanto à existência de pelo menos um grupo temático e no preenchimento dos livros de registro de tuberculose e hanseníase. Já os municípios de menor porte apresentaram melhores resultados nas ações de acolhimento, busca ativa de adolescentes de risco e no conjunto das ações de saúde da mulher. Entretanto, de uma forma geral, as equipes apresentaram dificuldades para realizar várias ações, sendo necessário capacitar os profissionais, a fim de desenvolverem suas práticas conforme preconiza a Política Nacional de Atenção Básica.AbstractThe study aimed to evaluate the family health teams process of work in the state of Pernambuco based on population size in the year 2009. Structured questionnaires were applied to 154 teams of 24 municipalities assessed and items related to the organization of the team were applied to the joint community and to specific programs. The results showed that teams of larger municipalities stood out from the others regarding the existence of at least one thematic group and the completion of the registration books of tuberculosis and leprosy. The smaller municipalities showed better results when performing the hosting actions, active search for risky adolescents and into the actions of women’s health. However, in general, the teams had difficulties to perform various actions, showing that it is necessary to train professionals in order to develop their practices as recommended by the National Primary Care Policy

Spatiotemporal Analysis of the Population Risk of Congenital Microcephaly in Pernambuco State, Brazil.

Since an outbreak in Brazil, which started in 2015, Zika has been recognized as an important cause of microcephaly. The highest burden of this outbreak was in northeast Brazil, including the state of Pernambuco. The prevalence of congenital microcephaly in Pernambuco state was estimated from the RESP (Registro de Eventos em Saúde Pública) surveillance system, from August 2015 to August 2016 inclusive. The denominators were estimated at the municipality level from official demographic data. Microcephaly was defined as a neonatal head circumference below the 3rd percentile of the Intergrowth standards. Smoothed maps of the prevalence of microcephaly were obtained from a Bayesian model which was conditional autoregressive (CAR) in space, and first order autoregressive in time. A total of 742 cases were identified. Additionally, high and early occurrences were identified in the Recife Metropolitan Region, on the coast, and in a north-south band about 300 km inland. Over a substantial part of the state, the overall prevalence, aggregating over the study period, was above 0.5%. The reasons for the high occurrence in the inland area remain unclear

Spatial analysis of epidemiological and quality indicators of health services for leprosy in hyperendemic areas in Northeastern Brazil

Leprosy is a public health problem due to the physical disabilities and deformities it causes. This study aimed to describe new leprosy cases using an operational classification and analyzing spatial patterns by means of epidemiological and quality indicators of health services in Pernambuco State, Brazil, between 2005 and 2014. This was an ecological study performed in 184 municipalities grouped into 12 health regions units for analysis. To analyze spatial patterns, the Bayesian local empirical method and Moran’s spatial autocorrelation indicator were applied and box and Moran maps were used. Individuals aged ≥15 years old, grade zero physical disability and complete remission as the treatment outcome were predominant in both paucibacillary and multibacillary cases, the only difference was the predominance of females (n=9,286; 63.00%) and males (n=8,564; 60.70%), respectively. These variables were correlated (p<0.05) with the operational classification. The overall detection rate showed three high-priority areas; the indicator rate of grade 2 physical disability revealed clusters in regions IV, V, and VI; and the indicator rate of cases with some degree of disability showed precarious municipalities in seven health regions. Pernambuco maintains an active chain of transmission and ongoing endemicity of leprosy. Therefore, spatial analysis methods allow the identification of priority areas for intervention, thereby supporting the disease elimination strategy

Avaliação da assistência hospitalar materna e neonatal: índice de completude da qualidade

OBJECTIVE Develop an index to evaluate the maternal and neonatal hospital care of the Brazilian Unified Health System. METHODS This descriptive cross-sectional study of national scope was based on the structure-process-outcome framework proposed by Donabedian and on comprehensive health care. Data from the Hospital Information System and the National Registry of Health Establishments were used. The maternal and neonatal network of Brazilian Unified Health System consisted of 3,400 hospitals that performed at least 12 deliveries in 2009 or whose number of deliveries represented 10.0% or more of the total admissions in 2009. Relevance and reliability were defined as criteria for the selection of variables. Simple and composite indicators and the index of completeness were constructed and evaluated, and the distribution of maternal and neonatal hospital care was assessed in different regions of the country. RESULTS A total of 40 variables were selected, from which 27 single indicators, five composite indicators, and the index of completeness of care were built. Composite indicators were constructed by grouping simple indicators and included the following variables: hospital size, level of complexity, delivery care practice, recommended hospital practice, and epidemiological practice. The index of completeness of care grouped the five variables and classified them in ascending order, thereby yielding five levels of completeness of maternal and neonatal hospital care: very low, low, intermediate, high, and very high. The hospital network was predominantly of small size and low complexity, with inadequate child delivery care and poor development of recommended and epidemiological practices. The index showed that more than 80.0% hospitals had a low index of completeness of care and that most qualified heath care services were concentrated in the more developed regions of the country. CONCLUSIONS The index of completeness proved to be of great value for monitoring the maternal and neonatal hospital care of Brazilian Unified Health System and indicated that the quality of health care was unsatisfactory. However, its application does not replace specific evaluations.OBJETIVO Desenvolver índice para avaliar a assistência hospitalar materna e neonatal do Sistema Único de Saúde. MÉTODOS Estudo descritivo de corte transversal, com abrangência nacional, com base na tríade estrutura-processo-resultado proposta por Donabedian e na integralidade da assistência. Utilizaram-se dados do Sistema de Informações Hospitalares e do Cadastro Nacional de Estabelecimentos de Saúde. Conformaram a rede materna e neonatal do SUS, 3.400 hospitais que realizaram pelo menos 12 partos/2009, ou cujo número de partos realizados representassem 10,0% ou mais no total de internações/2009. Relevância e confiabilidade foram definidas como critérios para seleção das variáveis a serem utilizadas. Foi realizada a construção e valoração dos indicadores simples, compostos e do índice de completude, e distribuição da rede hospitalar materna e neonatal nas regiões do País. RESULTADOS Selecionaram-se 40 variáveis a partir das quais foram construídos 27 indicadores simples, cinco indicadores compostos e o índice de completude. Os indicadores compostos foram construídos a partir da agregação dos indicadores simples, conformando as dimensões: porte hospitalar, complexidade, prática assistencial ao parto, práticas hospitalares recomendáveis e práticas epidemiológicas. O índice de completude agregou as cinco dimensões, fracionado em ordem crescente, originando cinco níveis de completude da assistência hospitalar materna e neonatal: baixíssima, baixa, intermediária, alta e altíssima. A rede hospitalar foi predominantemente de pequeno porte, baixa complexidade, com desempenho inadequado das práticas assistenciais ao parto e com baixo desenvolvimento das práticas recomendáveis e epidemiológicas. O índice mostrou que mais de 80,0% dos hospitais apresentam baixa completude e que os serviços mais qualificados concentraram-se nas regiões mais desenvolvidas do País. CONCLUSÕES O índice de completude mostrou ser de grande valor para o monitoramento da assistência hospitalar materna e neonatal do Sistema Único de Saúde e apontou que a qualidade dessa assistência foi insatisfatória. No entanto, seu emprego não substitui avaliações específicas

Factores asociados a la ocurrencia de tuberculosis y su distribución espacial en una ciudad brasileña, 1991-2010

Se buscó identificar los factores asociados a la incidencia de tuberculosis y a la distribución espacial de la enfermedad en Olinda, Pernambuco, entre 1991 y 2010. Para el estudio de los factores asociados a la enfermedad se aplicó la regresión de Poisson y se utilizó la razón de morbilidad estandarizada para el análisis exploratorio espacial. Si bien se observó una reducción en la incidencia media de tuberculosis en Olinda, la tasa se mantiene alta comparada con la media nacional. El mapeo por quinquenios sugiere aumentos hasta 2005, con una caída entre 2006 y 2010, además de la persistencia de alta incidencia en áreas con mayores necesidades socioeconómicas. Las mayores incidencias de tuberculosis estuvieron asociadas a la proporción de analfabetos, de jefes de familia sin ingresos, de domicilios sin abastecimiento de agua, de adultos mayores, a la presencia de más de un caso de retratamiento en el sector censal, y a los domicilios con más de un caso nuevo de tuberculosis. Se concluye que es necesario incorporar el componente espacial a la organización de los servicios de salud y la planificación de la vigilancia epidemiológica de la tuberculosis.This article seeks to identify factors associated with the incidence of tuberculosis and the spatial distribution of the disease in Olinda, Pernambuco, from 1991 to 2010. In order to study the factors associated with the disease, Poisson regression was applied and standardized morbidity ratios were utilized for the spatial exploratory analysis. Although a reduction in the average incidence of tuberculosis in Olinda was observed, the rate remains high in comparison with the national average. Mapping according to five-year periods suggests rate increases until 2005, with a decline between 2006 and 2010 and the persistence of high incidence in areas of greater socioeconomic need. The highest tuberculosis incidence rates were associated in each area with the proportions of illiteracy, of heads of household without income, of households lacking water supply and of older adults, as well as with the presence of cases of retreatment and of households with two or more new cases of tuberculosis. Incorporating a spatial component is key for the organization of health services and the planning of epidemiological surveillance for tuberculosis

Factores asociados a la ocurrencia de tuberculosis y su distribución espacial en una ciudad brasileña, 1991-2010

This article seeks to identify factors associated with the incidence of tuberculosis and the spatial distribution of the disease in Olinda, Pernambuco, from 1991 to 2010. In order to study the factors associated with the disease, Poisson regression was applied and standardized morbidity ratios were utilized for the spatial exploratory analysis. Although a reduction in the average incidence of tuberculosis in Olinda was observed, the rate remains high in comparison with the national average. Mapping according to five-year periods suggests rate increases until 2005, with a decline between 2006 and 2010 and the persistence of high incidence in areas of greater socioeconomic need. The highest tuberculosis incidence rates were associated in each area with the proportions of illiteracy, of heads of household without income, of households lacking water supply and of older adults, as well as with the presence of cases of retreatment and of households with two or more new cases of tuberculosis. Incorporating a spatial component is key for the organization of health services and the planning of epidemiological surveillance for tuberculosis.Se buscó identificar los factores asociados a la incidencia de tuberculosis y a la distribución espacial de la enfermedad en Olinda, Pernambuco, entre 1991 y 2010. Para el estudio de los factores asociados a la enfermedad se aplicó la regresión de Poisson y se utilizó la razón de morbilidad estandarizada para el análisis exploratorio espacial. Si bien se observó una reducción en la incidencia media de tuberculosis en Olinda, la tasa se mantiene alta comparada con la media nacional. El mapeo por quinquenios sugiere aumentos hasta 2005, con una caída entre 2006 y 2010, además de la persistencia de alta incidencia en áreas con mayores necesidades socioeconómicas. Las mayores incidencias de tuberculosis estuvieron asociadas a la proporción de analfabetos, de jefes de familia sin ingresos, de domicilios sin abastecimiento de agua, de adultos mayores, a la presencia de más de un caso de retratamiento en el sector censal, y a los domicilios con más de un caso nuevo de tuberculosis. Se concluye que es necesario incorporar el componente espacial a la organización de los servicios de salud y la planificación de la vigilancia epidemiológica de la tuberculosis

A Dynamic Analysis of Tuberculosis Dissemination to Improve Control and Surveillance

Background: Detailed analysis of the dynamic interactions among biological, environmental, social, and economic factors that favour the spread of certain diseases is extremely useful for designing effective control strategies. Diseases like tuberculosis that kills somebody every 15 seconds in the world, require methods that take into account the disease dynamics to design truly efficient control and surveillance strategies. The usual and well established statistical approaches provide insights into the cause-effect relationships that favour disease transmission but they only estimate risk areas, spatial or temporal trends. Here we introduce a novel approach that allows figuring out the dynamical behaviour of the disease spreading. This information can subsequently be used to validate mathematical models of the dissemination process from which the underlying mechanisms that are responsible for this spreading could be inferred. Methodology/Principal Findings: The method presented here is based on the analysis of the spread of tuberculosis in a Brazilian endemic city during five consecutive years. The detailed analysis of the spatio-temporal correlation of the yearly geo-referenced data, using different characteristic times of the disease evolution, allowed us to trace the temporal path of the aetiological agent, to locate the sources of infection, and to characterize the dynamics of disease spreading. Consequently, the method also allowed for the identification of socio-economic factors that influence the process. Conclusions/Significance: The information obtained can contribute to more effective budget allocation, drug distribution and recruitment of human skilled resources, as well as guiding the design of vaccination programs. We propose that this novel strategy can also be applied to the evaluation of other diseases as well as other social processes.Instituto do Milenio REDE-TBConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)[0012-05.03/04]Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)[0203-1.05/08