Construction of multilevel statistical models in health research: Foundations and generalities / Fundamento y generalidades de la construcción de modelos estadísticos multinivel en el ámbito de la investigación en salud

This topic review aims to present a global vision of multilevel analysis models' applicability to health research, explaining its theoretical, methodological, and statistical foundations. We describe the basic steps to build these models and examples of their application according to the data hierarchical structure. It ir worth noticing that before using these models, researchers must have a rationale for needing them, and a statistical evaluation accounting for the variance percentage explained by the observations grouping effect. The requirements to conduct this type of analysis depends on special conditions such as the type of variables, the number of units per level, or the type of hierarchical structure. We conclude that multilevel analysis models are a useful tool to integrate information, considering the complexity of the relationships and interactions involved in most health conditions, including the loss of independence between observation units.

Este trabajo tiene como objetivo presentar una mirada global de la aplicabilidad de los modelos de análisis multinivel en el ámbito de la investigación sanitaria. Ofrece información sobre los fundamentos teóricos, metodológicos y estadísticos y, además, menciona los pasos básicos para la construcción de estos modelos, y da ejemplos de su uso, según la estructura jerárquica de los datos. Cabe resaltar que, antes de utilizar estos modelos, se requiere contar con un soporte teórico sobre la necesidad de uso y una valoración estadística que dé cuenta del porcentaje de varianza explicada por el efecto de agrupación de las observaciones. Los requisitos para llevar a cabo este tipo de análisis dependen de condiciones especiales como el tipo de variables, la cantidad de unidades por nivel o el tipo de estructura jerárquica. Se concluye que los modelos de análisis multinivel son una herramienta útil para lograr la integración de información, dadas la complejidad de las relaciones y las interacciones que determinan la mayoría de las condiciones de salud, incluida la pérdida de independencia entre las unidades de observación.

Fundamento y generalidades de la construcción de modelos estadísticos multinivel en el ámbito de la investigación en salud

Este trabajo tiene como objetivo presentar una mirada global de la aplicabilidad de los modelos de análisis multinivel en el ámbito de la investigación sanitaria. Ofrece información sobre los fundamentos teóricos, metodológicos y estadísticos y, además, menciona los pasos básicos para la construcción de estos modelos, y da ejemplos de su uso, según la estructura jerárquica de los datos. Cabe resaltar que, antes de utilizar estos modelos, se requiere contar con un soporte teórico sobre la necesidad de uso y una valoración estadística que dé cuenta del porcentaje de varianza explicada por el efecto de agrupación de las observaciones. Los requisitos para llevar a cabo este tipo de análisis dependen de condiciones especiales como el tipo de variables, la cantidad de unidades por nivel o el tipo de estructura jerárquica. Se concluye que los modelos de análisis multinivel son una herramienta útil para lograr la integración de información, dadas la complejidad de las relaciones y las interacciones que determinan la mayoría de las condiciones de salud, incluida la pérdida de independencia entre las unidades de observación.

This topic review aims to present a global vision of multilevel analysis models' applicability to health research, explaining its theoretical, methodological, and statistical foundations. We describe the basic steps to build these models and examples of their application according to the data hierarchical structure. It ir worth noticing that before using these models, researchers must have a rationale for needing them, and a statistical evaluation accounting for the variance percentage explained by the observations grouping effect. The requirements to conduct this type of analysis depends on special conditions such as the type of variables, the number of units per level, or the type of hierarchical structure. We conclude that multilevel analysis models are a useful tool to integrate information, considering the complexity of the relationships and interactions involved in most health conditions, including the loss of independence between observation units.

Trabajo colaborativo entre academia y autoridades de salud en tiempos de COVID-19: experiencia en Santander, Colombia

Introducción: Colombia es uno de los países con mayor número de casos de COVID-19 en América Latina y el Caribe. Los gobiernos no pueden trabajar solos en una crisis de gran intensidad, por lo que las alianzas y la colaboración Gobierno-academia toman un valor preponderante. Objetivo: Sistematizar la experiencia del trabajo colaborativo que se realizó entre actores académicos de la región y las autoridades de salud del departamento de Santander, Colombia, en el marco de la emergencia sanitaria por COVID-19 durante 2020-2021. Metodología: A partir de la sistematización de experiencias y desde el enfoque crítico social se realizó un abordaje cualitativo con ocho actores clave del sector académico y de la autoridad en salud que participaron activamente en la alianza. Se hizo una revisión documental y se realizaron entrevistas semiestructuradas. Resultados: Una vez declarada la emergencia sanitaria, de manera rápida se conformaron dos grupos de trabajo colaborativo, uno entre academia y actores gubernamentales del municipio de Bucaramanga y otro entre academia y actores gubernamentales departamentales; ambos grupos se conformaron de manera voluntaria, pero se diferenciaron en su forma de organización. El trabajo colaborativo y voluntario brindó apoyo a las autoridades en salud, principalmente en la fase de preparación para afrontar la pandemia, traducción y difusión del conocimiento, vigilancia epidemiológica y actividades de fortalecimiento de la capacidad de respuesta. Conclusiones: El apoyo brindado por el equipo colaborativo fue muy proliferativo en actividades e intervenciones, no obstante, se presentaron dificultades y una de ellas fue que un número importante de sus recomendaciones no fueron atendidas por las autoridades sanitarias. Las dificultades presentadas no son diferentes a las ya reportadas en otras emergencias de salud pública, por lo que se requiere continuar fortaleciendo las relaciones Gobierno-academia para que se pueda trazar de manera proactiva una agenda que contribuya a superar las limitaciones que se reportan en este trabajo.

Introduction: Colombia is one of the countries with the highest number of COVID-19 cases in Latin America and the Caribbean. In a health crisis of high intensity, governments cannot work alone, so alliances and collaboration between Government and academia take on a preponderant value. Objective: Systematize the experience of the collaborative work carried out between academic actors in the region and the health authorities from the Department of Santander, Colombia in the framework of the health emergency due to COVID-19 during 2020-2021. Methods: Based on the systematization of experiences and from the critical social approach, a qualitative approach was carried out with eight key actors from the academic sector and the health authority that actively participated in the alliance. Documentary review and semi-structured interviews were conducted. Results: Once the health emergency was declared, two collaborative working groups were quickly formed, one between academia and government actors of the municipality of Bucaramanga and another between academia and departmental government actors; both groups were formed voluntarily but differed in their form of organization. The collaborative and voluntary work provided support to health authorities mainly in the preparation phase to face the pandemic, knowledge translation and dissemination, epidemiological surveillance, and response capacity-building activities. Conclusions: The support provided by the collaborative team was very proliferative in activities and interventions; however, difficulties occurred and one of them was that a significant number of their recommendations were not addressed by the health authorities. The difficulties presented are not different from those already reported in other public health emergencies, so it is necessary to continue strengthening the relations between Government-Academia, so that they can proactively draw up an agenda that contributes to overcoming the limitations that are reported in this work.

Exposure to low-dose radiation in occupational settings and ischaemic heart disease: a systematic review and meta-analysis.

Ionising radiation is a human carcinogen, but the evidence is less clear that exposure to low-dose ionising radiation (LDIR) increases the risk of adverse cardiovascular outcomes. We synthesised the literature of chronic occupational exposure to LDIR and cardiovascular disease, particularly for ischaemic heart disease (IHD).The literature search was conducted using three databases including studies published between 1990 and 2022. A quality assessment of the studies was completed using the Office of Health and Assessment and Translation Risk of Bias Rating Tool. We conducted meta-analyses for IHD mortality using random effects models using measures of excess relative risk per sievert (ERR/Sv) obtained from internal cohort comparisons, as well as with standardised mortality ratios (SMRs) from external cohort comparisons.We identified 2189 articles, and of these, 26 provided data on IHD and were retained. Most studies were classified as having a 'moderate' level of risk of bias. Fourteen and 10 studies reporting external radiation doses were included in meta-analyses using SMR and ERR/Sv, respectively. The meta-summary SMR was 0.81 (95% CI 0.74 to 0.89) with evidence of reduced risk but high heterogeneity across studies. For internal cohort measures, the summary ERR/Sv for a lagged exposure of 10 years was 0.10 (95% CI 0.01 to 0.20) with low heterogeneity. The subgroup analysis by lagged exposure time showed the strongest association were for the 15 and 20 years lag.Our findings suggest that occupational exposure to LDIR increases the risk IHD mortality and highlight the relevance of internal cohort comparisons.

Latin America and the Caribbean Code Against cancer 1st edition: Environment, occupation, and cancer.

Within the framework of the Latin America and Caribbean region (LAC) Code Against Cancer 1st edition, the current work presents recommendations to reduce exposure to environmental and occupational carcinogenic agents relevant for LAC. Using the methodology established by the International Agency for Research on Cancer (IARC) in the World Code Against Cancer Framework and experience from developing the European Code Against Cancer 4th edition, a working group of LAC cancer-prevention experts reviewed the list of Group I IARC carcinogenic agents, identified prevalent environmental and occupational exposures in the region, and proposed evidence-based cancer prevention recommendations suited to the epidemiological, socioeconomic, and cultural conditions of LAC countries. Two sets of recommendations were drafted: those targeting the general public and a second set for policymakers. Outdoor and indoor air pollution, ultra-violet radiation and occupational exposures to silica dust, asbestos, benzene, diesel, and welding fumes were identified as prevalent carcinogens in LAC and as agents that could be reduced or eliminated to prevent cancers. Recommendations for additional risk factors were not included due to insufficient data of their attributable burden in LAC (sunbeds, radon, aflatoxin), or lack of a clear preventive action to be taken by the individual (arsenic in drinking water, medical radiation), or lack of evidence of carcinogenicity effect (bisphenol A, phthalates, and pesticides). A broad consensus was reached on environmental and occupational carcinogenic exposures present throughout the LAC region and on individual-level and public policy-level recommendations to reduce or eliminate these exposures. Key educational content for the dissemination of these recommendations was also developed as part of LAC Code Against Cancer 1st Edition.

Barriers and facilitators of academia-government collaboration in the context of the COVID-19 pandemic in Colombia: a qualitative study.

The COVID-19 pandemic highlighted the importance of strengthening collaborations between academia and government. The development and maintenance of these collaborative relationships is a complex and dynamic process, particularly during public health emergencies. This study was aimed at identifying and analysing factors that acted as barriers and facilitators in the collaboration process between academia and government during the COVID-19 pandemic in the five largest cities in Colombia. The study used a qualitative approach based on the systematization of experiences. A total of 25 semi-structured interviews were conducted with local actors from government and academia during 2021. Participants identified a variety of situations that involved individual, institutional and relational factors that acted as barriers and facilitators, and which have been previously reported in other countries and contexts not related to pandemics. Based on participant reports, two additional factors emerged, one corresponding to situations related to the pandemic management process itself and another related to structural or systemic conditions that involved government processes and the Colombian health system. Despite the challenges posed by the pandemic, the health emergency brought about shared feelings of local commitment and a willingness to work through interdisciplinary teams to address the pandemic with the least adverse effects on the community. Other facilitators of the collaborative process that were recognized were the importance of timely access to data and transparent analyses, as well as government decisions being informed by the perspectives of academics. The main barriers identified by both actors were excessive centralization of the pandemic's management and the need for rapid decision-making processes under high levels of uncertainty. In addition, the fragmentation of services in the health system posed a barrier to the interventions that were suggested by the collaborative work. Our results suggest that government-academia collaborations should be implemented as ongoing participatory processes integrating various sectors, actors and disciplines.

Exposición a material particulado y su relación con el cáncer de mama. Mecanismos fisiopatológicos / Exposure to particulate matter and its association to breast cancer. Pathophysiological mechanisms

Introducción. El cáncer de mama es el tipo de cáncer que genera más muertes en mujeres en el mundo. Aunque se reconoce el aporte de factores genéticos, hormonales y de estilos de vida como sus principales causas, las hipótesis que señalan que la contaminación del ambiente juega un papel importante en su desarrollo, han tomado mucha fuerza en los últimos años. Estas hipótesis surgen debido a que el aumento en la incidencia del cáncer de mama coincide con procesos de industrialización, además de mayor presencia en regiones urbanas y con altos niveles de contaminación. El objetivo de este artículo fue consolidar información sobre los mecanismos fisiopatológicos que puedan explicar la relación entre cáncer de mama y la contaminación por material particulado. Metodología. Se realizó una búsqueda de literatura en PubMed, Google Académico y Epistemonikos para documentos publicados sobre el tema desde enero de 2016 hasta el 3 de agosto de 2022. Resultados. Se encontró que algunos de los mecanismos que podrían explicar dicha relación incluyen: alteraciones endocrinas que favorecen cambios hormonales, induciendo el crecimiento mamario; cambios en las características histológicas del tejido normal, como involución reducida de unidades lobulares ductales terminales; formación de aductos de hidrocarburos aromáticos policíclicos-ácido desoxirribonucleico (HAP-ADN), con mutación específica del gen TP53; activación de la proliferación en la línea celular MCF-7; y, alteraciones en la metilación del ADN. Conclusión. Si bien órganos distales como la mama no son la primera entrada de los contaminantes ambientales al cuerpo, estos sí pueden verse afectados tras la exposición a largo plazo, a través de diferentes mecanismos de disrupción endocrina y daño al ADN principalmente

Breast cancer is the type of cancer that causes the most deaths in women worldwide. Although the contribution of genetic, hormonal and lifestyle factors are recognized as its main causes, the hypotheses that indicate that environmental pollution has an important role in its development have taken on great strength during the last years. These hypotheses are based on the increase in the incidence of breast cancer that coincides with industrialization processes, in addition to its greater presence in urban regions with high levels of pollution. The aim of this study was to consolidate information on the pathophysiological mechanisms that can explain the relationship between breast cancer and air pollution by particulate matter. Methodology. A literature search was carried out in PubMed, Google Scholar and Epistemonikos for documents published on this topic from January 2016 until August 3rd 2022. Results. Some of the mechanisms that could explain this association include endocrine alterations that favor hormonal changes, inducing breast growth; changes in the histological characteristics of normal tissue such as reduced involution of terminal duct lobular units; formation of polycyclic aromatic hydrocarbons-deoxyribonucleic acid (PAH-DNA) adducts, with specific mutation of the TP53 gene; an increase in cell proliferation in the MCF-7 cell line; and alterations in DNA methylation. Conclusion. Although distal organs such as the breast are not the entry site of environmental pollutants into the body, they can be affected after prolonged exposure, mainly through different mechanisms of endocrine disruption and DNA damage

Análisis de conglomerado de cáncer infantil y su relación con proximidad a fuentes de contaminación industrial en el Área Metropolitana del Valle de Aburrá, 2000-2015

Objetivo: Este estudio evaluó el efecto de la proximidad a fuentes industriales de contaminación del aire sobre la aparición de clústeres de casos de cáncer infantil en el Área Metropolitana del Valle de Aburrá, del departamento de Antioquia, durante el período 2000-2015. Metodología: La información de casos de cáncer infantil en menores de 15 años residentes del área metropolitana se obtuvo del Registro Poblacional de Cáncer de Antioquia, de dicho periodo. Se identificaron 32 conglomerados industriales, a partir del inventario de la autoridad ambiental local. Se realizaron pruebas de escaneo circular de Kulldorf locales y focalizadas, para detectar clústeres de cáncer infantil en los municipios y alrededor de los conglomerados industriales respectivamente. Se usó un modelo de regresión multivariable ajustado por estrato socioeconómico, para evaluar el efecto de las variables espaciales. Resultados: La tasa de incidencia específica en el Valle de Aburrá para el periodo evaluado fue de 117,13 casos por millón de niños menores de 15 años. Las tasas de incidencia más altas se presentaron en los municipios de Medellín y Sabaneta. La prueba de Kulldorf identificó 12 clústeres espaciales y 8 espacio-temporales con significación estadística en 7 de los municipios, particularmente en Bello y Medellín. Las pruebas focalizadas identificaron clústeres alrededor de 20 conglomerados industriales. En los modelos multivariables, un conglomerado en Bello evidenció asociación estadísticamente significativa e inversa entre la incidencia y la distancia al conglomerado con direccionalidad sureste. Conclusión: Algunos conglomerados espacio-temporales de cáncer infantil en el Área Metropolitana del Valle de Aburrá entre 2000 y 2015 están relacionados con proximidad a fuentes industriales de contaminación del aire.

Objective: This study evaluated the effect of proximity to industrial sources of air pollution on the occurrence of clusters of childhood cancer cases in the Aburrá Valley Metropolitan Area, Department of Antioquia, during the 2000-2015 period. Methodology: The information on childhood cancer cases in children under 15 years of age residing in the metropolitan area was obtained from the Registro Poblacional de Cáncer de Antioquia (Antioquia Cancer Population Registry) for that period. 32 industrial clusters were identified based on the local environmental authority's inventory. Local and targeted Kulldorff's circular scan tests were performed to detect childhood cancer clusters in the municipalities and surrounding the industrial clusters, respectively. We used a multivariate regression model adjusted for socioeconomic strata to assess the effect of spatial variables. Results: The specific incidence rate in the Aburrá Valley for the evaluated period was 117.13 cases per million children under 15 years of age. The highest incidence rates occurred in the municipalities of Medellín and Sabaneta. The Kulldorff test identified 12 spatial clusters and 8 space-time clusters that were statistically significant in 7 municipalities, particularly in Bello and Medellín. The targeted tests identified childhood cancer clusters surrounding 20 industrial clusters. In multivariate models, an industrial cluster in Bello showed a statistically significant inverse association between incidence and distance from the industrial cluster toward the southeast. Conclusion: Some space-time childhood cancer clusters in the Aburrá Valley Metropolitan Area between 2000 and 2015 are related to proximity to industrial sources of air pollution.

Objetivo: Este estudo avaliou o efeito da proximidade a fontes industriais de poluição do ar sobre a aparição de agrupações de casos de câncer infantil na Área Metropolitana do Valle de Aburrá, do departamento de Antioquia, durante o período 2000-2015. Metodología: A informação de casos de câncer infantil em menores de 15 anos residentes da área metropolitana foi obtida do Registro Populacional de Câncer de Antioquia, de tal período. Foram identificados 32 conglomerados industriais, a partir do inventário da autoridade ambiental local. Foram realizados testes de varredura circular de Kulldorf locais e focalizados, para detectar agrupações de casos de câncer infantil nos municípios e ao redor dos conglomerados industriais, respectivamente. Foi usado um modelo de regressão multivariável ajustado por nivel socioeconômico, para avaliar o efeito das variáveis espaciais. Resultados: A taxa de incidência específica no Valle de Aburrá para o período avaliado foi de 117,13 casos por milhão de crianças menores de 15 anos. As maiores taxas de incidencia apresentaram-se nos municípios de Medellín e Sabaneta. O teste de Kulldorf identificou 12 agrupações de casos espaciais e 8 espaço-temporais com significação estatística em 7 dos municípios, particularmente em Bello e Medellín. As provas focalizadas identificaram agrupações de casos ao redor de 20 conglomerados industriais. Nos modelos multivariáveis, um conglomerado em Bello evidenciou associação estatisticamente significativa e inversa entre a incidência e a distância com o conglomerado orientado ao sudeste. Conclusão: Algumas agrupações de casos espaço-temporais de câncer infantil na Área Metropolitana do Valle del Aburrá entre 2000 e 2015 estão relacionadas com a proximidade a fontes industriais de poluição do ar.

Desarrollo y resultados de la respuesta institucional dirigida a la comunidad universitaria UIS frente a la pandemia por COVID-19 durante 2020-2021 / Development and results of the institutional response at UIS for the COVID-19 pandemic during 2020 and 2021

Resumen Introducción: La pandemia por COVID-19 ha requerido de la respuesta institucional de las diferentes organizaciones para mitigar sus efectos. Objetivo: Describir el proceso de respuesta institucional dirigida a la comunidad universitaria de la Universidad Industrial de Santander (UIS) frente la epidemia por COVID-19 y analizar los resultados de los procesos implementados durante 2020 y 2021. Metodología: Estudio descriptivo de tipo mixto con un componente cualitativo descriptivo de la organización y desarrollo de la respuesta institucional y un componente cuantitativo descriptivo del análisis de los casos sospechosos y confirmados de COVID-19 en la comunidad universitaria UIS. Resultados: La respuesta institucional UIS comenzó desde marzo de 2020 y comprendió lineamientos y adaptaciones de tipo académico y laboral y un plan de respuesta que incluyó 6 componentes de acción y un retorno gradual a la presencialidad. Durante 2021 se confirmaron 272 casos en funcionarios y docentes y 208 casos en estudiantes, con una tendencia que reflejó la dinámica de transmisión local, pero con menor letalidad. Conclusiones: La respuesta institucional UIS frente a la epidemia por COVID-19 inició tempranamente e incluyó diferentes componentes que permitieron un retorno progresivo con baja transmisión en las sedes. Los aspectos por mejorar estuvieron relacionados con la cobertura, calidad y continuidad del diagnóstico y atención oportunos, conexas a las competencias y fragmentación propias del sistema de salud, y con la visibilidad del plan y sus resultados dentro de la comunidad universitaria.

Abstract Introduction: The COVID-19 pandemic has required the institutional response of different organizations to mitigate its effects. Objective: To describe the institutional response process for the COVID-19 pandemic at the Universidad Industrial de Santander (UIS) and analyze the results of the processes implemented during 2020 and 2021. Methodology: Descriptive mixed study with a qualitative component of the organization and development of the institutional response, and a descriptive quantitative component of the analysis of suspected and confirmed cases of COVID-19. Results: The UIS institutional response began in March 2020. The plan included academic and employment guidelines and adaptations, a response plan that included 6 action components and a gradual return to attendance. During 2021, 272 cases were confirmed in employees and professors, and 208 cases in students with a trend that reflected the dynamics of local transmission, but with lower lethality. Conclusions: The UIS institutional response to the COVID-19 epidemic began early and included different components that allowed for a progressive return with low transmission. The aspects to improve were related to the coverage, quality and continuity of timely diagnosis and care related to competencies and fragmentation of the health system, and the visibility of the plan and its results within the university community.

Clustering of non-leukemia childhood cancer in Colombia: a nationwide study.

Background: Childhood cancer is considered one the most important causes of death in children and adolescents, despite having a low incidence in this population. Spatial analysis has been previously used for the study of childhood cancer to study the geographical distribution of leukemias. This study aimed to identify the presence of space-time clusters of childhood of cancer excluding leukemia in Colombia between 2014 and 2017. Methods: All incident cancer cases (excluding leukemia) in children under the age of 15 years that had been confirmed by the National Surveillance System of Childhood Cancer between 2014 and 2017 were included. Kulldorf's circular scan test was used to identify clusters using the municipality of residence as the spatial unit of analysis and the year of diagnosis as the temporal unit of analysis. A sensitivity analysis was conducted with different upper limit parameters for the at-risk population. Results: A total of 2006 cases of non-leukemia childhood cancer were analyzed, distributed in 432 municipalities with a mean annual incidence rate of 44 cases per million children under the age of 15. Central nervous system (CNS) tumors were the most frequent type. Four spatial clusters and two space-time clusters were identified in the central and southwest regions of the country. In the analysis for CNS tumors, a spatial cluster was identified in the central region of the country.  Conclusions: The distribution of non-leukemia childhood cancer seems to have a clustered distribution in some Colombian regions that may suggest infectious or environmental factors associated with its incidence.

Alternancia Escolar: un reto para garantizar la salud y la vida de la comunidad educativa / Educational Alternation: A challenge to protect the health and life of the school community

La inesperada llegada de la pandemia, enfrentó a todo el mundo a cambios drásticos en la forma de vida que se disfrutaba en épocas de normalidad, obligando a la población a diferentes tipos de confinamientos. Estos trajeron consigo el cierre de casi todos los sectores y en consecuencia la interrupción de muchos servicios esenciales, como las intervenciones en el sector educativo. Muchas de estas intervenciones estaban dirigidas, además de a la educación misma, a brindar protección a los escolares, detectar condiciones de riesgo de violencia intrafamiliar, maltrato y trabajo infantil, suministrar raciones alimenticias, vigilar el cumplimiento del esquema de vacunación y a evitar la deserción escolar, entre otras. Aunque los escolares no son el grupo más afectado por COVID-19, un reciente estudio de UNICEF realizado en 87 países revela que, en noviembre de 2020, los niños y los adolescentes representaron el 11% del total de infecciones1, mientras que, en Colombia, la proporción de casos pediátricos (menores de 18 años) se estima entre 7-8% y representan el 0.025% del total de fallecimientos2. Aunque se ha reportado que el riesgo de infección en escolares es menor que el del personal docente y administrativo en instituciones de educación, esta discrepancia pudiera estar sobreestimada debido a una menor probabilidad de detección considerando el curso predominantemente asintomático de la infección en niños. Sin embargo, COVID-19 puede ser una enfermedad severa en los menores, contribuyendo no solo al número de ingresos a unidades de cuidados intensivo sino al de casos fatales3. En términos de la transmisión, un estudio conducido en población infantil evidenció que esta ocurre con mayor frecuencia en el entorno familiar, relacionándose directamente con el estadio de enfermedad del caso índice: comparados con casos asintomáticos aquellos en etapa pre sintomática fueron responsables del doble de casos secundarios (1/3 versus 1/6)4. Esto indica que los niños infectados constituyen una fuente importante de contagio para sus pares, con evidencia de mayor transmisión en el nivel de secundaria comparado con el de primaria5, así como para los miembros del personal docente y administrativo de sus escuelas. Estos últimos, a su vez generarían nuevos casos de infección en la comunidad estudiantil y dada cuenta de su mayor movilidad, también en la población general6. La importancia que la socialización tiene en los procesos de enseñanza-aprendizaje y en el desarrollo psicológico de los niños, niñas, adolescentes y jóvenes es ampliamente reconocida. Además, es conocido el impacto beneficioso que tienen las actividades educativas en la salud física y mental y en general, en la probabilidad que nuestros niños alcancen todo su potencial y tengan una vida plena. En esta dirección, y ajustándose a la coyuntura, el sector educativo ha tenido que instaurar nuevas estrategias, pasando a la modalidad virtual (asistida por las tecnologías de la información y las comunicaciones ­ TICs) y a diferentes modelos de alternancia escolar. La alternancia se ofrece en diferentes modalidades como la híbrida, en la que es posible que un grupo de estudiantes reciban de manera presencial la clase y el resto lo hagan de manera virtual en forma sincrónica, con opciones de participación en ambos espacios. Otra estrategia es el desarrollo de la clase presencial y de manera asincrónica el desarrollo de actividades virtuales en casa, es decir, con grupos de estudiantes que tendrán asistencia a la institución y trabajo virtual o so-lamente asistencia a la institución. Las instituciones que no acojan la alternancia continuarán con su oferta pedagógica en la modalidad virtual. Cualquiera de los modelos de alternancia que las instituciones adopten trae consigo la presencialidad y, por lo tanto, la necesidad de realizar acciones para la disminución del riesgo, la identificación de casos (sintomáticos y asintomáticos) y sus contactos y el seguimiento y aislamiento, cuando ello se requiera. Nadie niega la importancia del regreso a la escuela, pero ésta debe hacerse en condiciones seguras que garanticen la protección de la salud y la vida de escolares, maestros, personal administrativo y de apoyo y de sus familias. Para lograr este objetivo se requiere adherencia y adaptación en cada institución educativa de los protocolos de bioseguridad emanados de los ministerios de educación y salud. Además, se requiere tener en cuenta la situación epidemiológica actual del municipio o área metropolitana y de la evolución de la epidemia en la población local y la comunidad educativa institucional. Esto último, el conocimiento cabal de la situación epidemiológica local e institucional es crucial para poder decidir responsablemente cuando se abre o se cierra una institución educativa, a fin de preservar la salud, el bienestar y la vida de sus integrantes. En particular, al momento de tomar estas decisiones, es esencial tener en cuenta los siguientes aspectos: La situación de la transmisión y la velocidad de contagio del SARS-CoV-2 en la localidad y cómo esto afectará el entorno educativo. El nivel de capacidad de los servicios de salud y especialmente las EPS para detectar y aislar casos sintomáticos y asintomáticos; detectar brotes o conglomerados de casos; identificar y seguir contactos de los casos; y establecer cercos epidemiológicos para detener la transmisión de la enfermedad dentro de la institución educativa. En qué medida la infección y enfermedad en familiares de los estudiantes, profesores y otro personal de la institución, constituye un factor de riesgo para los niños y viceversa. Dada la dinámica de la transmisión, los protocolos de bioseguridad por sí mismos, no garantizan la reducción del riesgo, si no se acompañan del cumplimiento estricto de los mismos, del acondicionamiento de las instituciones educativas para garantizar ambientes seguros, y de un análisis técnico, permanente y veraz de las condiciones de la pandemia en la localidad. Garantizar la ventilación adecuada y los recambios de aire, de los diferentes espacios de las instituciones educativas especialmente en las áreas cerradas, es un factor de especial importancia para disminuir la transmisión del virus. Por lo tanto, este aspecto es un asunto clave en la adecuación de las instituciones educativas. La decisión de abrir una institución de educación, debe estar precedida de un trabajo conjunto entre los escolares, los padres, los maestros, el personal directivo, y el personal de salud, con el fin de fijar los lineamientos básicos de las decisiones y acciones tanto en los asuntos de salud, como de protección de los escolares y del personal y sus familias, la coordinación con las entidades de salud y la anticipación de la mayoría de las situaciones que puedan derivarse de los procesos de apertura. La institución educativa debe definir, con el apoyo del sector salud, los indicadores que les permitan decidir en qué momento la institución debe cerrarse, bien sea de manera parcial o total, dada la existencia de casos en una burbuja (grupos estables de convivencia) o en varias burbujas. Además de los aspectos relacionados con minimizar el riesgo y disminuir la transmisión, en el proceso de apertura deben contemplarse otros aspectos tales como: garantizar el acceso a la educación a distancia a todos los escolares de las poblaciones distantes o rurales, marginadas, de escasos recursos, con discapacidad y cuyos familiares pertenecen a grupos de alto riesgo. Garantizar mecanismos pedagógicos que les permitan a los escolares, superar la brecha en que pudieron haber caído, por las dificultades de acceso a la educación virtual. Proveer la asistencia en salud y nutrición a los escolares, así como la atención a las niñas y adolescentes para la prevención del embarazo, el acoso y el abuso sexual. Ante la situación tan cambiante de la pandemia, es necesario tomar las decisiones de la apertura de las instituciones, en medio de gran incertidumbre. Son muchos los retos que el sector educativo tiene que superar. Pero en la planeación y toma de decisiones, como bien lo enuncia la UNICEF, "la respuesta debe servir de catalizador para mejorar los resultados del aprendizaje, hacer más equitativo el acceso a la enseñanza y fortalecer la protección, la salud y la seguridad de los niños"1. En consecuencia, si bien es prioritario el regreso a la presencialidad especialmente en los niveles de educación básica, deberán primar el principio de la protección y bienestar de los niños y los principios éticos, por encima de cualquier interés político o económico, del ejercicio de autoridad, o de una falsa sensación de seguridad. Conflicto de intereses: Los autores declaran no tener conflicto de intereses.

The unexpected arrival of the pandemic brought everyone to face drastic changes in the way people used to live in normal times, forcing them to experience different types of home confinement. These resulted in the closure of almost all sectors and, consequently, the disruption of many essential services, such as educational interventions. Many of these interventions were aimed, apart from education itself, at providing protection to schoolchildren, detecting risk conditions of domestic violence, child abuse and child labor, providing school meals, monitoring compliance with immunization programs and preventing school dropout, among others.Although schoolchildren are not the group most affected by COVID-19, a recent UNICEF study conducted in 87 countries found that in November 2020, children and adolescents accounted for 11% of reported COVID-19 infections1, while in Colombia the number of pediatric COVID-19 cases (patients aged < 18 years) is estimated at 7-8% representing 0.025% of deaths2.While the risk of infection in schoolchildren has been reported to be lower than that of teaching and administrative staff in schools, this difference may be overestimated due to a lower probability of detection considering the predominantly asymptomatic course of infection in children. However, COVID-19 can be a severe disease in young people, contributing not only to the number of admissions to intensive care units but also to the number of deaths3.As for COVID-19 transmission, a study conducted with children showed that it occurs more frequently in the home environment, which is directly related to the stage of disease of the index case (that is, compared to asymptomatic cases, those in the pre- 2Revista Cuidarte mayo - agosto 2021;12(2): e2244http://dx.doi.org/10.15649/cuidarte.2244symptomatic stage were responsible for twice as many secondary cases as index case (1/3 versus 1/6)4. This means that infected children are an important source of infection for their peers, suggesting greater transmission rates in high school compared to elementary school5, as well as in teachers and school administrative staff. The latter would in turn lead to new cases of infection in the school community and, given their greater mobility, also in the general population6.The importance of socialization in teaching-learning processes and the psychological development of children, adolescents and young people is widely recognized. Furthermore, the positive impacts that educational activities have on physical and mental health and more generally, the chances that our children will reach their full potential and have a fulfilling life are well-known. In this regard, and in response to the current situation, the education sector needed to implement new strategies, switching to online education (assisted by information and communications technology (ICT)) and different models of educational alternation.Educational alternation can be offered in different modes such as hybrid learning, in which a group of students has in-person classes and the rest of the group receive online instruction in a synchronous way, providing options for participation in both spaces. Another strategy combines in-person instruction and asynchronous online activities at home, i.e., a group of students will have in-person and remote instruction and another one will only have in-person instruction. Schools that do not implement any educational alternation model will continue with their educational online offer. Every alternation model implemented by schools entails face-to-face instruction and, therefore, the need to take actions for risk reduction, identification of symptomatic and asymptomatic cases, contact tracing, subsequent follow up and self-isolation, when required.No one denies the importance of returning to school. However, this should be safely done to protect the health and life of students, teachers, school administrative and support staff and their families. To this end, each school is required to adhere to and adapt biosafety protocols issued by the ministries of education and health. In addition, the current epidemiological situation of each municipality or urban area as well as the course of the outbreak in the local population and school community need to be taken into account. A complete understanding of the local and institutional epidemiological situation is crucial to make responsible decisions when reopening or closing schools to protect the health, wellbeing and life of the school community.The following aspects are essential to consider when making these decisions:-Transmission and speed rates of SARS-CoV-2 infection in the local population and their impact on the educational environment.-Health care services capacity, especially in Health Promotion Agencies (EPSs in Spanish), to detect and isolate symptomatic and asymptomatic cases; detect outbreaks or clusters of This means that infected children are an important source of infection for their peers, suggesting greater transmission rates in high school compared to elementary school5, as well as in teachers and school administrative staff. A complete understanding of the local and institutional epidemiological situation is crucial to make responsible decisions when reopening or closing schools to protect the health, wellbeing and life of the school community. 3Revista Cuidarte mayo - agosto 2021;12(2): e2244http://dx.doi.org/10.15649/cuidarte.2244COVID-19 cases; identify and trace contacts and implement epidemiological fences to stop disease transmission within the school community.-The degree to which coronavirus infection and disease in students, teachers and other school staff 's relatives can become a risk factor for children and vice versa.-Considering transmission dynamics of COVID-19, biosafety protocols alone do not ensure risk reduction unless supported by strict compliance, school preparation to ensure safe environments and technical, ongoing and accurate analysis of the pandemic situation in the local territory.-Proper ventilation and air circulation of school areas, especially indoors, is a key factor in reducing virus transmission. Therefore, it is a key issue to consider in school preparation.-The decision to reopen a school should be preceded by joint efforts among students, parents, teachers, school board and healthcare personnel to define the basic guidelines for decision making and management actions on healthcare issues, protection of students, staff and their families, as well as coordination with healthcare agencies and anticipation of potential challenges that may arise from school reopening.-Supported by the healthcare sector, schools need to define the indicators that will help them decide when the school should be closed, either partially or totally, given the existence of cases in one bubble (stable coexistence groups) or several bubbles.-In addition to risk and transmission reduction, aspects such as access to distance learning to all schoolchildren from remote, rural, marginalized, low-income, disabled populations and those having relatives at higher risk for COVID-19 should be considered in school reopenings.-Teaching mechanisms should be in place to overcome any gap that schoolchildren may have fallen into due to difficulties in accessing online learning.-Implementation of health and nutrition assistance for children, in addition to health care services for girls and adolescents to prevent pregnancy, harassment and sexual abuse.Faced with the rapidly changing situation of the pandemic, it is necessary to make decisions on school reopening in the midst of great uncertainty. Although there are many challenges that the education sector needs to overcome, during planning and decision making "the response should serve as a catalyst to improve learning outcomes, increase equitable access to education and strengthen the protection, health and safety of children"1 as stated by UNICEF. Consequently, while the return to in-person education is a priority, especially for basic education, the principle of protection and wellbeing of children and ethical principles should take precedence over any political or economic interest, the exercise of authority or a false sense of security.Conflict of interest statement: The authors declare that there is no conflict of interest.

A inesperada chegada da pandemia, enfrentou a todos mudanças drásticas na forma de vida que se desfrutava em épocas de normalidade, obrigando a população a diferentes tipos de confinamento. Estes levaram ao encerramento de quase todos os setores e, consequentemente, à interrupção de muitos serviços essenciais, como as intervenções no sector da educação. Muitas destas intervenções eram dirigidas, além da própria educação, a proporcionar proteção aos alunos, identificar as condições de risco de violência doméstica, maus-tratos e trabalho infantil, fornecer porções alimentares, controlar o cumprimento do plano de vacinação e evitar a deserção escolar, entre outras. Embora os alunos não sejam o grupo mais afetado pela COVID-19, um estudo recente da UNICEF realizado em 87 países revela que, em Novembro de 2020, crianças e adolescentes representaram 11% do total de infeção1, enquanto, na Colômbia, a proporção de casos pediátricos (menores de 18 anos) é estimada entre 7-8% e representam 0.025% do total de mortes2. Embora se tenha relatado que o risco de infecção em escolas é menor do que o do pessoal docente e administrativo em instituições de educação 3, esta discrepância pode ser sobrestimada devido a uma menor probabilidade de detecção, tendo em conta o curso predominantemente assintomático da infecção em crianças. No entanto, COVID-19 pode ser uma doença grave em crianças, contribuindo não só para o número de entradas nas unidades de cuidados intensivos, mas também para o número de casos fatais3. Em termos de transmissão, um estudo conduzido em população infantil evidenciou que a transmissão acontece com maior 2Revista Cuidarte mayo - agosto 2021;12(2): e2244http://dx.doi.org/10.15649/cuidarte.2244frequência no ambiente familiar, relacionadas diretamente com o estádio da doença do caso índice: comparados com casos assintomáticos aqueles em etapa pré-sintomática foram responsáveis pelo dobro de casos secundários (1/3 versus 1/6)4. Isto indica que as crianças infectadas constituem uma fonte importante de contágio para os seus pares, com evidência de maior transmissão no nível secundário comparado com o primário5, como para os membros do pessoal docente e administrativo das suas escolas. Estes últimos, por sua vez, gerariam novos casos de infecção na comunidade estudantil e dada a sua maior movimentação, também na população geral6. A importância que a socialização tem nos processos de ensino-aprendizagem e no desenvolvimento psicológico dos meninos, meninas, adolescentes e jovens é amplamente reconhecida. Além disso, é conhecido o impacto benéfico das atividades educativas na saúde física e mental e em geral, na probabilidade que nossas crianças alcançarem todo o seu potencial e terem uma vida plena. Neste sentido, e adaptando-se à conjuntura, o setor da educação teve que instaurar novas estratégias, passando à modalidade virtual (assistida pelas tecnologias da informação e das comunicações - TICs) e a diferentes modelos de alternância escolar. A alternância é oferecida em diferentes modalidades, como a híbrida, na qual um grupo de estudantes pode receber a aula em forma presencial e os restantes podem fazê-lo de forma virtual e sincronizada, com opções de participação em ambos os espaços. Outra estratégia é o desenvolvimento da classe presencial e de maneira assíncrona o desenvolvimento de atividades virtuais em casa, ou seja, com grupos de estudantes que terão assistência à instituição e trabalho virtual ou apenas assistência à instituição. As instituições que não acolham a alternância continuarão com sua oferta pedagógica na modalidade virtual. Qualquer dos modelos de alternância que as instituições adotem traz consigo a presencialidade e, portanto, a necessidade de realizar ações para a diminuição do risco, a identificação de casos (sintomáticos e assintomáticos) e respectivos contatos, bem como a monitorização e o isolamento, se necessário.Ninguém nega a importância do regresso à escola, mas isso deve ser feito em condições seguras que garantam a proteção da saúde e da vida de alunos, professores, pessoal administrativo e de apoio e das suas famílias. Para alcançar este objetivo, requer-se adesão e adaptação em cada instituição educativa dos protocolos de biossegurança emitidos dos ministérios de educação e saúde. Além disso, é necessário ter em conta a situação epidemiológica atual do município ou área metropolitana e a evolução da epidemia na população local e na comunidade educativa institucional. Este último, o pleno conhecimento da situação epidemiológica local e institucional é crucial para poder decidir responsavelmente quando se abre ou fecha uma instituição educativa, a fim de preservar a saúde, o bem-estar e a vida de seus integrantes. Em particular, no momento das tomadas de decisões, é essencial ter em conta os seguintes aspectos: Isto indica que as crianças infectadas constituem uma fonte importante de contágio para os seus pares, com evidência de maior transmissão no nível secundário comparado com o primário5, como para os membros do pessoal docente e administrativo das suas escolas., o pleno conhecimento da situação epidemiológica local e institucional é crucial para poder decidir responsavelmente quando se abre ou fecha uma instituição educativa, a fim de preservar a saúde, o bem-estar e a vida de seus integrantes. 3Revista Cuidarte mayo - agosto 2021;12(2): e2244http://dx.doi.org/10.15649/cuidarte.2244- A situação da transmissão e a velocidade de contágio do SARS-CoV-2 na localidade e como isso afetará o ambiente educacional- O nível de capacidade dos serviços de saúde e, em especial, das EPS (entidades promotoras de saúde) para detectar e isolar casos sintomáticos e assintomáticos; detectar surtos ou conglomerados de casos; identificar e acompanhar os contatos dos casos e estabelecer barreiras epidemiológicas para impedir a transmissão da doença dentro da instituição de ensino. - Em que medida a infecção e a doença nos familiares dos estudantes, professores e outro pessoal da instituição constituem um fator de risco para as crianças e vice-versa.- Dada a dinâmica da transmissão, os protocolos de biossegurança, por si só, não garantem a redução do risco, se não forem acompanhados do cumprimento estrito dos mesmos, do acondicionamento das instituições educativas para garantir ambientes seguros, e de uma análise técnica, permanente e verdadeira das condições da pandemia na localidade.- Garantir a ventilação adequada e a mudança de ar dos diferentes espaços das instituições educativas, especialmente nas áreas fechadas, é um fator de especial importância para diminuir a transmissão do vírus. Portanto, este aspecto é uma questão chave na adequação das instituições de ensino. - A decisão de abrir uma instituição de educação deve ser precedida de um trabalho conjunto entre os escolares, os pais, os professores, o pessoal dirigente, e o pessoal de saúde, a fim de estabelecer as orientações básicas das decisões e ações, tanto em matéria de saúde como de proteção dos estudantes e do pessoal e suas respectivas famílias, a coordenação com as instituições de saúde e a antecipação da maioria das situações que possam resultar dos processos de abertura. - A instituição educativa deve definir, com o apoio do sector da saúde, os indicadores que lhes permitam decidir em que momento a instituição deve ser encerrada, seja de forma parcial ou total, dada a existência de casos numa bolha (grupos estáveis de convivência) ou em várias bolhas. - Além dos aspectos relacionados com minimizar o risco e diminuir a transmissão, O processo de abertura deve contemplar outros aspectos, tais como: garantir o acesso à educação à distância a todos os alunos das populações distantes ou rurais, marginalizadas, de escassos recursos, com deficiência e cujos familiares pertencem a grupos de alto risco.- Garantir mecanismos pedagógicos que permitam aos alunos, superar a brecha em que podem ter caído, pelas dificuldades de acesso à educação virtual. - Fornecer cuidados de saúde e nutrição às crianças em idade escolar, bem como de cuidados às meninas e adolescentes para a prevenção da gravidez e do assédio sexual.Perante a situação tão variável da pandemia, é necessário tomar as decisões de abertura das instituições, no meio de grande incerteza. São muitos os desafios que o setor da educação tem que enfrentar. Mas na planificação e tomada de decisão, como bem o indica a UNICEF, "a resposta deve servir de catalisador para melhorar os resultados da aprendizagem, tornar mais equitativo o acesso ao ensino e reforçar a proteção, a saúde e a segurança das crianças"1. Embora seja prioritário o regresso à presencialidade, especialmente nos níveis de educação básica, deverão prevalecer o princípio da proteção e do bem-estar das crianças e os princípios éticos, acima de qualquer interesse político ou econômico, do exercício de autoridade ou de uma falsa sensação de segurança.Conflito de interesses: Os autores declaram não ter conflito de interesses.

Socioeconomic inequalities associated with mortality for COVID-19 in Colombia: a cohort nationwide study.

BACKGROUND: After 8 months of the COVID-19 pandemic, Latin American countries have some of the highest rates in COVID-19 mortality. Despite being one of the most unequal regions of the world, there is a scarce report of the effect of socioeconomic conditions on COVID-19 mortality in their countries. We aimed to identify the effect of some socioeconomic inequality-related factors on COVID-19 mortality in Colombia. METHODS: We conducted a survival analysis in a nation-wide retrospective cohort study of confirmed cases of COVID-19 in Colombia from 2 March 2020 to 26 October 2020. We calculated the time to death or recovery for each confirmed case in the cohort. We used an extended multivariable time-dependent Cox regression model to estimate the HR by age groups, sex, ethnicity, type of health insurance, area of residence and socioeconomic strata. RESULTS: There were 1 033 218 confirmed cases and 30 565 deaths for COVID-19 in Colombia between 2 March and 26 October. The risk of dying for COVID-19 among confirmed cases was higher in males (HR 1.68 95% CI 1.64 to 1.72), in people older than 60 years (HR 296.58 95% CI 199.22 to 441.51), in indigenous people (HR 1.20 95% CI 1.08 to 1.33), in people with subsidised health insurance regime (HR 1.89 95% CI 1.83 to 1.96) and in people living in the very low socioeconomic strata (HR 1.44 95% CI 1.24 to 1.68). CONCLUSION: Our study provides evidence of socioeconomic inequalities in COVID-19 mortality in terms of age groups, sex, ethnicity, type of health insurance regimen and socioeconomic status.

Childhood Leukemia in Small Geographical Areas and Proximity to Industrial Sources of Air Pollutants in Three Colombian Cities.

Acute leukemia is the most common childhood cancer and has been associated with exposure to environmental carcinogens. This study aimed to identify clusters of acute childhood leukemia (ACL) cases and analyze their relationship with proximity to industrial sources of air pollution in three capital cities in Colombia during 2000-2015. Incident ACL cases were obtained from the population cancer registries for the cities of Bucaramanga, Cali, and Medellín. The inventory of industrial sources of emissions to the air was obtained from the regional environmental authorities and industrial conglomerates were identified. The Kulldorf's circular scan test was used to detect city clusters and to identify clusters around industrial conglomerates. Multivariable spatial modeling assessed the effect of distance and direction from the industrial conglomerates controlling for socioeconomic status. We identified industrials sectors within a buffer of 1 km around industrial conglomerates related to the ACL clusters. Incidence rates showed geographical heterogeneity with low spatial autocorrelation within cities. The spatio-temporal tests identified one cluster in each city. The industries located within 1 km around the ACL clusters identified in the three cities represent different sectors. Exposure to air pollution from industrial sources might be contributing to the incidence of ACL cases in urban settings in Colombia.

A spatial analysis of childhood cancer and industrial air pollution in a metropolitan area of Colombia.

BACKGROUND: Air pollutants are considered carcinogenic to humans. In some European countries, an association between industrial air pollution and childhood cancer has been established. This relationship has not been addressed in Latin America, despite the spatial variability of air pollutants that may limit the extrapolation of the results to other geographical areas. OBJECTIVE: To conduct a spatial analysis of the relationship between childhood cancer and proximity to industrial sources of air pollution in a metropolitan area of Colombia. METHODS: Incident cases of childhood cancers were obtained from the Population-based Cancer Registry of the Metropolitan Area of Bucaramanga during 2000-2015. Local and focused cluster tests were used for the detection of spatial clusters, and the Poisson multivariable model was used to evaluate the combined effects of spatial variables. RESULTS: The Kulldorff's focused test found a significant spatial cluster (P < 0.001) around one industrial agglomerate and the multivariable model results suggests that the distance effect is modified by the directional effect of the wind. CONCLUSION: A spatial cluster of incident cases of childhood cancer occurred in the municipality of Bucaramanga, Colombia. Our finding supports the hypothesis that childhood cancer might be related with industrial air pollution exposure in a Latin American city.

Space-time clustering of childhood leukemia in Colombia: a nationwide study.

BACKGROUND: Leukemia is the most common cancer in childhood. The estimated incidence rate of childhood leukemia in Colombia is one of the highest in America and little is known about its spatial distribution. PURPOSE: To explore the presence of space-time clustering of childhood leukemia in Colombia. METHODS: We included children less than 15 years of age with confirmed diagnosis of acute leukemia reported to the national surveillance system for cancer between 2009 and 2017. Kulldorff's spatio-temporal scan statistics were used with municipality and year of diagnosis as units for spatial and temporal analysis. RESULTS: There were 3846 cases of childhood leukemia between 2009 and 2017 with a specific mean incidence rate of 33 cases per million person-years in children aged 0-14 years. We identified five spatial clusters of childhood leukemia in different regions of the country and specific time clustering during the study period. CONCLUSION: Childhood leukemia seems to cluster in space and time in some regions of Colombia suggesting a common etiologic factor or conditions to be studied.

Monthly-Term Associations Between Air Pollutants and Respiratory Morbidity in South Brazil 2013-2016: A Multi-City, Time-Series Analysis.

Most air pollution research conducted in Brazil has focused on assessing the daily-term effects of pollutants, but little is known about the health effects of air pollutants at an intermediate time term. The objective of this study was to determine the monthly-term association between air pollution and respiratory morbidity in five cities in South Brazil. An ecological time-series study was performed using the municipality as the unit of observation in five cities in South Brazil (Gravataí, Triunfo, Esteio, Canoas, and Charqueadas) between 2013 and 2016. Data for hospital admissions was obtained from the records of the Hospital Information Service. Air pollution data, including PM10, SO2, CO, NO2, and O3 (µg/m3) were obtained from the environmental government agency in Rio Grande do Sul State. Panel multivariable Poisson regression models were adjusted for monthly counts of respiratory hospitalizations. An increase of 10 µg/m3 in the monthly average concentration of PM10 was associated with an increase of respiratory hospitalizations in all age groups, with the maximum effect on the population aged between 16 and 59 years (IRR: Incidence rate ratio 2.04 (95% CI: Confidence interval = 1.97-2.12)). For NO2 and SO2, stronger intermediate-term effects were found in children aged between 6 and 15 years, while for O3 higher effects were found in children under 1 year. This is the first multi-city study conducted in South Brazil to account for intermediate-term effects of air pollutants on respiratory health.

Air Pollution and Suicide in Mexico City: A Time Series Analysis, 2000-2016.

The association between air pollution and suicide has recently been under examination, and the findings continue to be contradictory. In order to contribute evidence to this still unresolved question, the objective of the present study was to evaluate the association between air quality and daily suicides registered in Mexico City (MC) between 2000 and 2016. Air quality was measured based on exposure to particulate matter under 2.5 and 10 micrometers (µm) (PM2.5 and PM10, respectively), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), adjusting for weather variables (air temperature and relative humidity), and holidays. To this end, an ecologic time series analysis was performed using a Poisson regression model conditioned by time and stratified by gender and age groups. Models were also generated to explore the lagged and accumulative effects of air pollutants, adjusted by weather variables. The effects of the pollutants were very close to the null value in the majority of the models, and no accumulative effects were identified. We believe these results, in this case, no evidence of a statistical association, contribute to the current debate about whether the association between air pollution and suicide reported in the scientific literature reflects an actual effect or an uncontrolled confounding effect.