Combinación óptima del número de participantes y el número de medidas repetidas en estudios longitudinales con exposición variable en el tiempo

En el contexto de los estudios longitudinales observacionales, hemos obtenido los valores óptimos para el número de participantes y el número de medidas repetidas que maximizan la potencia para detectar el hipotético efecto, sin rebasar un presupuesto económico determinado, o que minimizan el coste total del estudio, alcanzando una potencia determinada. Hemos considerado una variable respuesta continua, cuya estructura de covarianza se supone exponencialmente amortiguada, y una exposición binaria variable en el tiempo, tanto para un efecto agudo y transitorio de la exposición, a través de una diferencia constante en la media entre expuestos y no expuestos, como para un efecto acumulativo, a través de una diferencia linealmente divergente. Hemos derivado expresiones cerradas para la solución del problema en el caso particular en que se supone que la estructura de covarianza de la respuesta es de simetría compuesta. Los resultados mostraron la importancia de la correlación intraclase de la exposición sobre la determinación de la combinación óptima del número de participantes y el número de medidas repetidas y, por tanto, sobre la potencia o el coste optimizados. Así, la incorrecta asunción de una exposición constante conduce a resultados sesgados en el cálculo del tamaño de la muestra y de la potencia o el coste del estudio. También analizamos la sensibilidad de los resultados a la presencia de datos faltantes debido al abandono de participantes durante el seguimiento, al cambio de la estructura de covarianza de la respuesta y a una prevalencia de la exposición variable en el tiempo. Como ejemplo, ilustramos algunos de estos resultados aplicando nuestros métodos en un estudio real. Además, proporcionamos el paquete de R optimalAllocation para realizar todos los cálculos necesarios para obtener la combinación óptima del número de participantes y el número de medidas repetidasIn the context of observational longitudinal studies, the aim of this work is to obtain optimal values of the number of participants and the number of repeated measurements that maximize the power to detect the hypothesized effect, given the total financial cost of the stud

Conditional poisson regression with random effects for the analysis of multi-site time series studies

The analysis of time series studies linking daily counts of a health indicator with environmental variables (e.g., mortality or hospital admissions with air pollution concentrations or temperature; or motor vehicle crashes with temperature) is usually conducted with Poisson regression models controlling for long-term and seasonal trends using temporal strata. When the study includes multiple zones, analysts usually apply a two-stage approach: first, each zone is analyzed separately, and the resulting zone-specific estimates are then combined using meta-analysis. This approach allows zone-specific control for trends. A one-stage approach uses spatio-temporal strata and could be seen as a particular case of the case–time series framework recently proposed. However, the number of strata can escalate very rapidly in a long time series with many zones. A computationally efficient alternative is to fit a conditional Poisson regression model, avoiding the estimation of the nuisance strata. To allow for zone-specific effects, we propose a conditional Poisson regression model with a random slope, although available frequentist software does not implement this model. Here, we implement our approach in the Bayesian paradigm, which also facilitates the inclusion of spatial patterns in the effect of interest. We also provide a possible extension to deal with overdispersed data. We first introduce the equations of the framework and then illustrate their application to data from a previously published study on the effects of temperature on the risk of motor vehicle crashes. We provide R code and a semi-synthetic dataset to reproduce all analyses presented.We acknowledge support from the grant CEX2018- 000806-S funded by MCIN/AEI/ 10.13039/501100011033, support from Ministry of Research and Universities of the Government of Catalonia (2021 SGR 01563) and support from the Generalitat de Catalunya through the CERCA Program.Peer ReviewedPostprint (published version

Construct validity of the physical activity questionnaire for adolescents (paq-a): maximal oxygen uptake

Introduction: The Physical Activity Questionnaire for adolescents (PAQ-A) is a cost-effective tool to assess physical activity (PA) patterns during adolescence and it has been widely used in research and field settings. Convergent validity of PAQ-A has been confirmed in several countries (Bervoets et al., 2014; Janz, Lutuchy, Wenthe, & Levy, 2008; Martinez-Gomez et al., 2009). However, the construct validity has often been overlooked. Therefore, the aim of this study was to analyze the construct validity of PAQ-A, using maximal oxygen uptake as criterion. Methods: One hundred and seventy-eight (n=99 boys, n=79 girls) adolescents (14.2±1.9 years, 21.1±4.1 BMI) participated in this study. A PA score was estimated by PAQ-A and additionally a sport history was recorded. BMI, waist circumference (WC) and fat mass percent (FMP) were assessed by anthropometric measurements as adiposity markers. Aerobic fitness (VO2Max) was assessed by a progressive continuous test (Chester Step Test). Associations between PA-score and criterions were analyzed by Spearman correlations; a one-way ANOVA was conducted to detect differences between each item level from the PAQ-A; independent sample t tests were used to compare values between boys and girls, and athletes and non-athletes. Results: The results showed moderate significant positive correlations between VO2Max and the PAQ-C for total score (rho = 0.28, P<0.01) and items 5, 6, 7 and 8 (rho = 0.24; rho = 0.25; rho = 0.22; rho = 0.25, all P<0.05; respectively). Adolescents who were enrolled in competitive and organized sport practice had higher scores on the questionnaire (2.8 vs 2.5 average score) as well as higher VO2Max values (37.4 vs 34.2 ml/kg/min). Discussion: Our data confirm the PAQ-A had acceptable construct validity when using VO2Max as criterion. Moreover, our results suggest that information from some items could be more related with some health markers than others. References: Bervoets, L., Van Noten, C., Van Roosbroeck, S., Hansen, D., Van Hoorenbeeck, K., Verheyen, E., . . . Vankerckhoven, V. (2014). Reliability and Validity of the Dutch Physical Activity Questionnaires for Children (PAQ-C) and Adolescents (PAQ-A). Arch Public Health, 72(1), 47. doi: 10.1186/2049-3258-72-47 Janz, K. F., Lutuchy, E. M., Wenthe, P., & Levy, S. M. (2008). Measuring activity in children and adolescents using self-report: PAQ-C and PAQ-A. Medicine and Science in Sports and Exercise, 40(4), 767-772. doi: 10.1249/MSS.0b013e3181620ed1 Martinez-Gomez, D., Martinez-de-Haro, V., Pozo, T., Welk, G. J., Villagra, A., Calle, M. E., . . . Veiga, O. L. (2009). [Reliability and validity of the PAQ-A questionnaire to assess physical activity in Spanish adolescents]. Rev Esp Salud Publica, 83(3), 427-439. Contact: [email protected] This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583), Spanish Ministry of Economy and Competitiveness (DEP2011-30565) and the University of Málaga (Campus of International Excellence Andalucía Tech).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

High Levels of Proinflammatory Cytokines, but Not Markers of Tissue Injury, in Unaffected Intestinal Areas from Patients with IBD

Intestinal alterations in IBD are triggered and maintained by an overexpression of proinflammatory cytokines. Additionally, increased immune activation has been found in the adjacent intestinal areas without displaying any apparent histological alterations, however, the regulatory environment is not well established. Biopsy specimens from patients with ulcerative colitis (UC) and Crohn's disease (CD), from both affected and unaffected areas, and also from a group of colonic biopsies from healthy controls, were included in our study. Cytokines and markers of mucosal damage were analyzed by real-time PCR, and some of the results confirmed by western-blot and ELISA. Levels of IFNγ, TNFα, IL-6, IL-15, IL-18, and IL-23 were increased (above healthy controls) in both affected and unaffected areas from IBD. IL-1β, IL-6, IL-12, and IL-27 were higher in affected areas compared to unaffected ones in UC but not CD. In general, a correlation was observed between mRNA levels of these cytokines and both iNOS and Granzyme B. SOCS-2 and SOCS-3 were also increased in the affected areas. In conclusion, the unaffected areas from IBD show increased levels of a restricted set of cytokines that may exert immune activating roles in these areas without being able to trigger tissue damage

Buenas prácticas de Manufactura (BPM) y HACCP en finca productora de aguacate hass en el departamento de Caldas municipio de Aranzazu vereda El Edén

En la finca productora ubicada en el municipio de Aranzazu Caldas se establece la producción de aguacate Hass (Persea americana hass), esta finca es una de las pioneras en establecer las normas ISO 2200 2018, ya que cuenta con los espacios apropiados para esta actividad agrícola, con el fin de obtener un producto final excelente, brindado así al consumidor final inocuidad alimentaria, con valores agregados tales como establecimiento de protocolos de producción limpios y certificables dentro de las Normas BPA Y BPM. En la actualidad el tema de inocuidad de alimentos hace referencia como el conjunto de acciones de primera necesidad para la producción, almacenamiento, distribución y preparación, con el fin de garantizar un producto final o terminado de excelente calidad y que no represente ningún riesgo para la salud (Minsalud s.f.). Gracias a la norma Internacional de Sistema de Gestión de la Seguridad Alimentaria - ISO 22000:2018, se establecen parámetros de técnicos de Análisis de Peligros y Puntos críticos de Control en cada uno de los procesos establecidos en la finca productora ubicada en el municipio de Aranzazu Caldas. Los protocolos generados por la finca productora ayudan a garantizar alimentos seguros e inocuos, por otro lado, se desarrollan acciones para mitigar el impacto ambiental generado por los proyectos agrícolas de la región y se asegura la calidad del producto. Esta finca brinda procesos oportunos para el control y desarrollo de la seguridad alimentaria en cada una de las áreas de la finca, buscando así ser pioneras en la implementación de BPA Y BPM, y desarrollando a cabalidad las especificaciones de la norma ISO 2200 2018.In the producing farm located in the municipality of Aranzazu Caldas Hass avocado (Persea americana hass), this farm is one of the pioneers in establishing the norms ISO 2200 2018, since it has the appropriate spaces for this agricultural activity, in order to obtain a final product excellent, thus providing the end consumer with food safety, with added values ​​such as protocol establishment clean and certifiable production facilities within the GAP AND BPM. Currently the issue of food safety refers to as the set of actions of first necessity for the production, storage, distribution and preparation, with the in order to guarantee a final or finished product of excellent quality and that does not represent any risk to health (Minsalud s.f.). Thanks to the International Standard for the Management System of the Food Safety - ISO 22000: 2018, parameters are established of Hazard Analysis and Critical Control Points technicians in each of the processes established in the producing farm located in the municipality of Aranzazu Caldas. The protocols generated by the producing farm help to guarantee safe and innocuous food, on the other hand, develop actions to mitigate the environmental impact generated by the agricultural projects of the region and the quality of the product. This nca provides timely processes for the control and development of food security in each of the areas of the farm, thus seeking to be pioneers in the implementation of GAP AND BPM, AND fully developing the specifications of the ISO standard 2200 2018

Plan de mejoramiento de clima organizacional en la IPS Fundación Nacer para Vivir

pag 14, pag 31Se analizó el ambiente de la organización de la IPS FUNDACION NACER PARA VIVIR, a través de un instrumento de medición (encuesta estructurada) el cual se aplicó a los empleados del área administrativa y asistencial como lo son la correlación social, políticas y administrativas, ejecución de tareas, escenarios de trabajo, ayudas laborales, Progreso y mejora personal, de estas que se realiza un análisis descriptivo, En ciertos aspectos se visualizan áreas de tensión esto hace que los empleados no den el máximo de capacidad en busca del mejor desempeño; La IPS FUNDACION NACER PARA VIVIR reconoce la importancia del recurso humano por lo que hay participación activa en la elaboración de estrategias y cumplimiento de objetivos. Por medio de la evaluación de estas variables se formulan acciones de mejora en la que la principal es que se implemente y ejecute por parte de la alta dirección de la IPS FUNDACION NACER PARA VIVIR Solución con un cartera de alicientes, actividades de capacitación y planificación de agendas para la integración grupal, que se enmarquen dentro del estilo de dirección adoptado por la empresa, así como que dentro del plan de acción corporativo se constituyan estrategias para mejorar el ambiente de la organización de la IPS FUNDACION NACER PARA VIVIR. Se estudia revisión teórica de los inicios de clima organizacional, creando y desarrollando un plan de acción para fortalecer el ambiente laboral de la IPS FUNDACION NACER PARA VIVIR y desarrollar comportamientos saludables que estimule un buen ambiente laboral para todas las áreasThe organizational climate of the IPS FUNDACION NACER PARA VIVIR was analyzed, through a measurement instrument (structured survey) which was applied to officials of the administrative and healthcare area such as Social Relations, administrative policies, performance of tasks, Working conditions, Labor benefits, Personal development, of which a descriptive analysis is carried out. In certain aspects, areas of tension are visualized. This means that officials do not give the maximum capacity in search of the best performance; The IPS FUNDACION NACER PARA VIVIR recognizes the importance of human resources, so there is active participation in the development of strategies and achievement of objectives. Through the analysis of the variables, recommendations for improvement are formulated in which the main one is that it be implemented and executed by the senior management of the IPS FUNDACION NACER PARA VIVIR Solution with a portfolio of incentives, training programs and integration programs group, that are framed within the management style adopted by the company, as well as that within the institutional action plan strategies are established to improve the organizational climate of the IPS FUNDACION NACER PARA VIVIR. Theoretical review of the beginnings of the organizational climate is studied, creating and developing an action plan to strengthen the work environment of the IPS FUNDACION NACER PARA VIVIR and develop healthy behaviors that stimulate a good work environment for all area

Identifying Factors Influencing Attention in Adolescents with a Co-Created Questionnaire : A Citizen Science Approach with Secondary Students in Barcelona, Spain

Studies on factors that can influence attention in healthy adolescents are recent and focus on recurrent topics. Students' contribution to public health research often revolves around collecting data but rarely around creating data collection instruments. The ATENC!Ó project reunited secondary students and scientists to create a questionnaire including factors that students thought could affect their attention. We conducted a cross-sectional study to assess whether the factors included in this questionnaire had an effect on attention in adolescents. A total of 1667 students (13-16 years old) from 28 schools in Barcelona performed a validated attention test and answered the questionnaire. The response speed consistency (attentiveness), expressed as hit reaction time standard error (HRT-SE, in ms), was used as the primary outcome. Analyses were conducted using conditional linear regression with school as strata, adjusted for sociodemographic characteristics and further stratified by gender and maternal social class. Some factors showed a negative influence on attention, including taking medication and not reading regularly. We found a significant 14.3% (95% confidence interval: 3.4%, 25.3%) higher median of HRT-SE (increase inattentiveness) among students who reported not having a good relationship with classmates. Students' input into research is relevant for advancing the knowledge production in public health

Quantification of unmethylated Alu (QUAlu): a tool to assess global hypomethylation in routine clinical samples

Hypomethylation of DNA is a hallmark of cancer and its analysis as tumor biomarker has been proposed, but its determination in clinical settings is hampered by lack of standardized methodologies. Here, we present QUAlu (Quantification of Unmethylated Alu), a new technique to estimate the Percentage of UnMethylated Alu (PUMA) as a surrogate for global hypomethylation. QUAlu consists in the measurement by qPCR of Alu repeats after digestion of genomic DNA with isoschizomers with differential sensitivity to DNA methylation. QUAlu performance has been evaluated for reproducibility, trueness and specificity, and validated by deep sequencing. As a proof of use, QUAlu has been applied to a broad variety of pathological examination specimens covering five cancer types. Major findings of the preliminary application of QUAlu to clinical samples include: (1) all normal tissues displayed similar PUMA; (2) tumors showed variable PUMA with the highest levels in lung and colon and the lowest in thyroid cancer; (3) stools from colon cancer patients presented higher PUMA than those from control individuals; (4) lung squamous cell carcinomas showed higher PUMA than lung adenocarcinomas, and an increasing hypomethylation trend associated with smoking habits. In conclusion, QUAlu is a simple and robust method to determine Alu hypomethylation in human biospecimens and may be easily implemented in research and clinical settings

Does surrounding greenness moderate the relationship between apparent temperature and physical activity? Findings from the PHENOTYPE project

Background: Physical activity can be affected by both meteorological conditions and surrounding greenness, but few studies have evaluated the effects of these environmental factors on physical activity simultaneously. This multi-city comparative study aimed to assess the synergetic effects of apparent temperature and surrounding greenness on physical activity in four European cities. Specifically, we aimed to identify an interaction between surrounding greenness and apparent temperature in the effects on physical activity. Methods: Data were collected from 352 adult residents of Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands), and Kaunas (Lithuania) as part of the PHENOTYPE study. Participants wore a smartphone for seven consecutive days between May-December 2013 and provided additional sociodemographic survey data. Hourly average physical activity (Metabolic Equivalent of Task (MET)) and surrounding greenness (NDVI) were derived from the Calfit mobile application collecting accelerometer and location data. Hourly apparent temperature was calculated from temperature and relative humidity, which were obtained from local meteorological stations along with other meteorological covariates (rainfall, windspeed, and sky darkness). We assessed the interaction effects of apparent temperature and surrounding greenness on hourly physical activity for each city using linear mixed models, while adjusting for meteorological, demographic, and time-related variables. Results: We found significant interactions between apparent temperature and surrounding greenness on hourly physical activity in all four cities. Significant quadratic effects of apparent temperature were found in the highest level of surrounding greenness for Stoke-on-Trent and Doetinchem, with 4% decrease in median MET observed for a 10°C departure from optimal temperature (15.2°C and 14.6°C, respectively). On the other hand, significant linear effects were found for higher levels of surrounding greenness in Barcelona and Kaunas, whereby an increase of 10°C was associated with ∼4% increase in median MET. Conclusion: Apparent temperature and surrounding greenness interacted in the effect on hourly physical activity across the four European cities, with varying effect between cities. While quadratic effects of temperature suggest diminishing levels of physical activity in the highest greenness levels in cities of temperate climates, the variation in surrounding greenness between cities could be further explored, particularly by looking at indoor-outdoor locations. The study findings support the need for evidence-based physical activity promotion and urban design