Indicadores de accesibilidad geográfica a los centros de atención primaria para la gestión de inequidades / Use of indicators of geographical accessibility to primary health care centers in addressing inequities

OBJETIVOS: Caracterizar los indicadores geográficos conforme a su utilidad para medir inequidades en el territorio; identificar y describir las áreas según sus grados de accesibilidad geográfica a los centros de atención primaria de salud (CAPS), y detectar poblaciones en riesgo desde la perspectiva del acceso a la atención primaria. MÉTODO: El análisis de accesibilidad espacial mediante sistemas de información geográfica (SIG) requirió de tres aspectos: la población sin cobertura médica, la distribución de los CAPS y la red de transporte público que los conecta. RESULTADOS: La construcción de indicadores de demanda (real, potencial y diferencial) y el análisis de los factores territoriales que intervienen en la movilidad de la población permitieron caracterizar los CAPS en relación a su entorno, contribuyendo al análisis, tanto en una perspectiva local como regional, y a la detección de diferentes zonas según niveles de conectividad a escala regional. CONCLUSIONES: Los indicadores construidos en el entorno SIG fueron de gran utilidad para el análisis de accesibilidad a los CAPS por la población vulnerable. La zonificación del territorio contribuyó a identificar inequidades al diferenciar áreas de demanda no satisfecha y la fragmentación de la conectividad espacial entre CAPS y transporte público.

OBJECTIVE: Characterize geographical indicators in relation to their usefulness in measuring regional inequities, identify and describe areas according to their degree of geographical accessibility to primary health care centers (PHCCs), and detect populations at risk from the perspective of access to primary care. METHODS: Analysis of spatial accessibility using geographic information systems (GIS) involved three aspects: population without medical coverage, distribution of PHCCs, and the public transportation network connecting them. RESULTS: The development of indicators of demand (real, potential, and differential) and analysis of territorial factors affecting population mobility enabled the characterization of PHCCs with regard to their environment, thereby contributing to local and regional analysis and to the detection of different zones according to regional connectivity levels. CONCLUSIONS: Indicators developed in a GIS environment were very useful in analyzing accessibility to PHCCs by vulnerable populations. Zoning the region helped identify inequities by differentiating areas of unmet demand and fragmentation of spatial connectivity between PHCCs and public transportation.

Iterative reconstruction of CT images on GPUs.

Although widely used in nuclear medicine (gamma-camera, single photon emission computed tomography (SPECT), positron emission tomography (PET)), iterative reconstruction has not yet penetrated in CT. The main reason for this is that data sets in CT are much larger than in nuclear medicine and iterative reconstruction then becomes computationally very intensive. Graphical Processing Units (GPUs) provide the possibility to reduce effectively the high computational cost of their implementation. It is the goal of this work to develop a GPU-based algorithm to reconstruct high quality images from under sampled and noisy projection data.

[Use of indicators of geographical accessibility to primary health care centers in addressing inequities]. / Indicadores de accesibilidad geográfica a los centros de atención primaria para la gestión de inequidades.

OBJECTIVE: Characterize geographical indicators in relation to their usefulness in measuring regional inequities, identify and describe areas according to their degree of geographical accessibility to primary health care centers (PHCCs), and detect populations at risk from the perspective of access to primary care. METHODS: Analysis of spatial accessibility using geographic information systems (GIS) involved three aspects: population without medical coverage, distribution of PHCCs, and the public transportation network connecting them. RESULTS: The development of indicators of demand (real, potential, and differential) and analysis of territorial factors affecting population mobility enabled the characterization of PHCCs with regard to their environment, thereby contributing to local and regional analysis and to the detection of different zones according to regional connectivity levels. CONCLUSIONS: Indicators developed in a GIS environment were very useful in analyzing accessibility to PHCCs by vulnerable populations. Zoning the region helped identify inequities by differentiating areas of unmet demand and fragmentation of spatial connectivity between PHCCs and public transportation.

Estimated radiation dose reduction using non-linear diffusion method in computed radiography.

In this paper we use a non-linear diffusion method to filter the inherent noise in a Computed Radiography (CR) for reducing the dose absorbed by the patients especially children in pediatric applications, related with the exposure mAs. The method is implemented in order to create a lower CR dose based on the selection of lower X-ray exposure and with a reduction of the noise using a non-linear diffusion method. The impact of several milliAmpere-seconds (mAs) setting on image quality has been studied using the RANDO phantom. The obtained results show good agreements between the filtered images and real images in terms of noise variance measurements. The new CR images allow medical researchers to analyze how a low dose affects the patient diagnosis.

Fast parallel algorithm for CT image reconstruction.

In X-ray computed tomography (CT) the X rays are used to obtain the projection data needed to generate an image of the inside of an object. The image can be generated with different techniques. Iterative methods are more suitable for the reconstruction of images with high contrast and precision in noisy conditions and from a small number of projections. Their use may be important in portable scanners for their functionality in emergency situations. However, in practice, these methods are not widely used due to the high computational cost of their implementation. In this work we analyze iterative parallel image reconstruction with the Portable Extensive Toolkit for Scientific computation (PETSc).

Medical image restoration with different types of noise.

The images obtained by X-Ray or computed tomography (CT) in adverse conditions may be contaminated with noise that can affect the detection of diseases. A large number of image processing techniques (filters) have been proposed to remove noise. These techniques depend on the type of noise present in the image. In this work, we propose a method designed to reduce the Gaussian, the impulsive and speckle noise and combined noise. This filter, called PGNDF, combines a non-linear diffusive filter with a peer group with fuzzy metric technique. The proposed filter is able to reduce efficiently the image noise without any information about what kind of noise might be present. To evaluate the filter performance, we use mammographic images from the mini- MIAS database which we have damaged by adding Gaussian, impulsive and speckle noises of different magnitudes. As a result, the proposed method obtains a good performance in most of the different types of noise.

Modelo espacial para el diseño de estrategias destinadas a la población bajo riesgo ambiental en la cuenca Matanza-Riachuelo / Spatial model to design strategies for population at environmental risk in the Matanza-Riachuelo basin

INTRODUCCION: La evaluación del impacto medioambiental sobre la salud requiere contar con un sistema que integre información sobre el estado del medio ambiente, el ecosistema y la población a nivel comunitario.OBJETIVO: Elaborar un modelo espacial que integre los factores ambientales riesgosos para la salud y que sea aplicable en la Cuenca Matanza-Riachuelo (CMR).METODOS: El desarrollo estuvo enmarcado en el análisis de riesgo y en procedimientos de evaluación multicriterio (EMC) integrada a los sistemas de información geográfica (SIG). Se aplicó EMC-SIG en áreas de la CMR para estratificar el territorio en zonas aptas y no aptas para residir. De este modo se buscó establecer comparaciones con la finalidad de obtener una estimación de la diferencia, no sesgada, entre niveles de riesgo ambiental. Los datos de salud se obtuvieron de diversas fuentes: Encuestas EFARS (percepción), Programa REMEDIAR (diagnósticos) y APS2000 (casos).RESULTADOS: El valor de aptitud del territorio resultó consistente como medida de exposición ambiental. La CMR presenta el 60% de la superficie en condición de habitabilidad, situación que incluye al 40% de la población residente. La accesibilidad geográfica a la atención médica no mostró obstáculos a la escala analizada. No obstante, en algunos barrios de la CMR se observó que hay vecinos que no asisten a los centros de salud porque priorizan otros aspectos de la vida cotidiana. Las condiciones ambientales potencialmente nocivas se hicieron manifiestas en el estado de salud de los entrevistados respecto a diarreas, enfermedades respiratorias y cáncer, así como en la mayor demanda de los servicios de salud, los perfiles de morbilidad durante 2007-2009 en la población de la Ciudad Autónoma de Buenos Aires/CMR y la representación de tramos viales peligrosos.CONCLUSIONES: La consideración de la CMR como una unidad de análisis permite establecer un único protocolo, capaz de medir la magnitud del riesgo en forma integral y establecer prioridades.

INTRODUCTION: In order to evaluate the environmental impact on health, it is necessary to develop a system that integrates information about state of the environment, ecosystem and population at community level.OBJECTIVE: To create a spatial model that integrates environmental factors threatening health and that can be applied in the Matanza-Riachuelo Basin (MRB).METHODS: The development was based on risk analysis and multi-criteria evaluation (MCE) procedures integrated with geographic information systems (GIS). GIS-MCE was applied in the MRB to stratify the territory in areas suitable or not suitable to live in. This comparison allowed to get an unbiased estimate of the difference between levels of environmental risk. Health data were collected from various sources: EFARS polls (perception), Remediar Program (diagnosis) and APS2000 (cases).RESULTS: The fitness value of the territory was consistent as a measure of environmental exposure. 60% of the MRB surface is habitable, that area includes 40% of the resident population. Geographical accessibility to health care showed no obstacles to the scale analysis. However, in some areas of the MRB, people choose not to attend health centers and give priority to other aspects of daily life. Environmental conditions with health risk were evident in the health status of those interviewed regarding diarrhea, respiratory diseases and cancer, as well as greater demand for health services, morbidity profiles during 2007-2009 in the population of Buenos Aires city/MRB and the representation of dangerous road sections.CONCLUSIONS: Considering the MRB as a unit of analysis allows to establish a single protocol, so as to measure the magnitude of a risk in a comprehensive manner and thus ser priorities.

Modelo espacial para el diseño de estrategias destinadas a la población bajo riesgo ambiental en la cuenca Matanza-Riachuelo / Spatial model to design strategies for population at environmental risk in the Matanza-Riachuelo basin

INTRODUCCION: La evaluación del impacto medioambiental sobre la salud requiere contar con un sistema que integre información sobre el estado del medio ambiente, el ecosistema y la población a nivel comunitario.OBJETIVO: Elaborar un modelo espacial que integre los factores ambientales riesgosos para la salud y que sea aplicable en la Cuenca Matanza-Riachuelo (CMR).METODOS: El desarrollo estuvo enmarcado en el análisis de riesgo y en procedimientos de evaluación multicriterio (EMC) integrada a los sistemas de información geográfica (SIG). Se aplicó EMC-SIG en áreas de la CMR para estratificar el territorio en zonas aptas y no aptas para residir. De este modo se buscó establecer comparaciones con la finalidad de obtener una estimación de la diferencia, no sesgada, entre niveles de riesgo ambiental. Los datos de salud se obtuvieron de diversas fuentes: Encuestas EFARS (percepción), Programa REMEDIAR (diagnósticos) y APS2000 (casos).RESULTADOS: El valor de aptitud del territorio resultó consistente como medida de exposición ambiental. La CMR presenta el 60% de la superficie en condición de habitabilidad, situación que incluye al 40% de la población residente. La accesibilidad geográfica a la atención médica no mostró obstáculos a la escala analizada. No obstante, en algunos barrios de la CMR se observó que hay vecinos que no asisten a los centros de salud porque priorizan otros aspectos de la vida cotidiana. Las condiciones ambientales potencialmente nocivas se hicieron manifiestas en el estado de salud de los entrevistados respecto a diarreas, enfermedades respiratorias y cáncer, así como en la mayor demanda de los servicios de salud, los perfiles de morbilidad durante 2007-2009 en la población de la Ciudad Autónoma de Buenos Aires/CMR y la representación de tramos viales peligrosos.CONCLUSIONES: La consideración de la CMR como una unidad de análisis permite establecer un único protocolo, capaz de medir la magnitud del riesgo en forma integral y establecer prioridades.

INTRODUCTION: In order to evaluate the environmental impact on health, it is necessary to develop a system that integrates information about state of the environment, ecosystem and population at community level.OBJECTIVE: To create a spatial model that integrates environmental factors threatening health and that can be applied in the Matanza-Riachuelo Basin (MRB).METHODS: The development was based on risk analysis and multi-criteria evaluation (MCE) procedures integrated with geographic information systems (GIS). GIS-MCE was applied in the MRB to stratify the territory in areas suitable or not suitable to live in. This comparison allowed to get an unbiased estimate of the difference between levels of environmental risk. Health data were collected from various sources: EFARS polls (perception), Remediar Program (diagnosis) and APS2000 (cases).RESULTS: The fitness value of the territory was consistent as a measure of environmental exposure. 60% of the MRB surface is habitable, that area includes 40% of the resident population. Geographical accessibility to health care showed no obstacles to the scale analysis. However, in some areas of the MRB, people choose not to attend health centers and give priority to other aspects of daily life. Environmental conditions with health risk were evident in the health status of those interviewed regarding diarrhea, respiratory diseases and cancer, as well as greater demand for health services, morbidity profiles during 2007-2009 in the population of Buenos Aires city/MRB and the representation of dangerous road sections.CONCLUSIONS: Considering the MRB as a unit of analysis allows to establish a single protocol, so as to measure the magnitude of a risk in a comprehensive manner and thus ser priorities.

[Multicriteria evaluation of environmental risk exposure using a geographic information system in Argentina]. / Evaluación multicriterio de la exposición al riesgo ambiental mediante un sistema de información geográfica en Argentina.

OBJECTIVE: Develop a spatial model that includes environmental factors posing a health hazard, for application in the Matanza-Riachuelo River Basin (MRB) in Argentina. METHODS: Multicriteria evaluation procedures were used with geographic information systems to obtain territorial zoning based on the degree of suitability for residence. Variables that characterize the habitability of housing and potential sources of basin pollution were geographically referenced. Health information was taken from the Risk Factor Survey (RFS) to measure the relative risk of living in unsuitable areas (exposed population) compared with suitable areas (unexposed population). RESULTS: Sixty percent of the MRB area is in suitable condition, a situation that affects 40% of residents. The rest of the population lives in unsuitable territory, and 6% live in the basin's most unsuitable conditions. Environmental conditions that are detrimental to health in the unsuitable areas became evident during the interviews through three of the pathologies considered: diarrheal diseases, respiratory diseases, and cancer. CONCLUSIONS: A regional analysis that provides valid information to support decisionmaking was obtained. Considering the basin as a unit of analysis allowed the use of a single protocol to undertake comprehensive measurement of the magnitude of risk and, thus, set priorities.

Evaluación multicriterio de la exposición al riesgo ambiental mediante un sistema de información geográfica en Argentina / Multicriteria evaluation of environmental risk exposure using a geographic information system in Argentina

OBJETIVO: Elaborar un modelo espacial que integre los factores ambientales que constituyen una amenaza para la salud, de aplicación en la cuenca del río Matanza-Riachuelo (CMR). MÉTODOS: Se implementaron procedimientos de evaluación multicriterio en el entorno de los sistemas de información geográfica para obtener una zonificación del territorio basada en grados de aptitud para residir. Se georreferenciaron variables que caracterizan las condiciones de habitabilidad de las viviendas y las posibles fuentes de contaminación de la cuenca. Se extrajo información de salud de la Encuesta de Factores de Riesgo (EFARS) para medir el riesgo relativo de vivir en zonas no aptas (población expuesta) en relación con las zonas aptas (población no expuesta). RESULTADOS: La CMR presenta 60 por ciento de su superficie en condición de aptitud, situación que afecta a 40 por ciento de la población residente. El resto de la población habita en un territorio no apto, y 6 por ciento se encuentra en la condición más desfavorable de la cuenca. Las condiciones ambientales adversas para la salud presentes en las zonas no aptas se hicieron manifiestas en el estado de salud de los entrevistados a través de tres de las patologías contempladas: diarreas, enfermedades respiratorias y cáncer. CONCLUSIONES: Se obtuvo un diagnóstico regional válido como información de apoyo en la toma de decisiones. La consideración de la cuenca como una unidad de análisis permitió establecer un único protocolo para medir la magnitud del riesgo en forma integral y, de esta manera, establecer prioridades.

OBJECTIVE: Develop a spatial model that includes environmental factors posing a health hazard, for application in the Matanza-Riachuelo River Basin (MRB) in Argentina. METHODS: Multicriteria evaluation procedures were used with geographic information systems to obtain territorial zoning based on the degree of suitability for residence. Variables that characterize the habitability of housing and potential sources of basin pollution were geographically referenced. Health information was taken from the Risk Factor Survey (RFS) to measure the relative risk of living in unsuitable areas (exposed population) compared with suitable areas (unexposed population). RESULTS: Sixty percent of the MRB area is in suitable condition, a situation that affects 40 percent of residents. The rest of the population lives in unsuitable territory, and 6 percent live in the basin's most unsuitable conditions. Environmental conditions that are detrimental to health in the unsuitable areas became evident during the interviews through three of the pathologies considered: diarrheal diseases, respiratory diseases, and cancer. CONCLUSIONS: A regional analysis that provides valid information to support decisionmaking was obtained. Considering the basin as a unit of analysis allowed the use of a single protocol to undertake comprehensive measurement of the magnitude of risk and, thus, set priorities.