Mapping life expectancy loss in Barcelona in 2020

© 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.We use a Bayesian spatio-temporal model, first to smooth small-area initial life expectancy estimates inBarcelona for 2020, and second to predict what small-area life expectancy would have been in 2020 inabsence of covid-19 using mortality data from 2007 to 2019. This allows us to estimate and map the small-area life expectancy loss, which can be used to assess how the impact of covid-19 varies spatially, and toexplore whether that loss relates to underlying factors, such as population density, educational level, orproportion of older individuals living alone. We find that the small-area life expectancy loss for men and forwomen have similar distributions, and are spatially uncorrelated but positively correlated with populationdensity and among themselves. On average, we estimate that the life expectancy loss in Barcelona in 2020 was of 2.01 years for men, falling back to 2011 levels, and of 2.11 years for women, falling back to 2006 levels.This work was supported by the grant PID2021-125380OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe.Peer ReviewedPostprint (published version

Bayesian spatiotemporal model for life expectancy mapping: changes in Barcelona from 2007 to 2018

When mapping life expectancy, and investigating its local variation in time, there is a conflict between using large areas and/or mortality data from long periods of time to have low variance life expectancy estimates, and using small areas and single-year mortality data to explore the space–time variation of life expectancy in detail, without bias. Here a Bayesian model is proposed to smooth annual small-area life expectancy estimates and help deal with that trade-off. The specific area effect on life expectancy, together with its spatial and temporal dependencies are modeled through random effects, while the effect of covariates is modeled through a fixed effect component. By smoothing life expectancy estimates directly, instead of smoothing age-specific mortality rates first the way done in the literature, the model used is easier to implement and interpret. The approach is illustrated, by using it to explore how life expectancy at birth of males and of females, and their gap, varied in space and in time in the city of Barcelona between 2007 and 2018, and their relationship with covariates. It is found that, on average, life expectancy has been growing by 0.23 years per year for males and 0.15 years per year for females. The female life expectancy is becoming more spatially homogeneous than the male one, while the rate of life expectancy growth for males turns out to be more homogeneous than for females.Peer ReviewedPostprint (published version

A unified approach to authorship attribution and verification

In authorship attribution, one assigns texts from an unknown author to either one of two or more candidate authors by comparing the disputed texts with texts known to have been written by the candidate authors. In authorship verification, one decides whether a text or a set of texts could have been written by a given author. These two problems are usually treated separately. By assuming an open-set classification framework for the attribution problem, contemplating the possibility that none of the candidate authors is the unknown author, the verification problem becomes a special case of attribution problem. Here both problems are posed as a formal Bayesian multinomial model selection problem and are given a closed-form solution, tailored for categorical data, naturally incorporating text length and dependence in the analysis, and coping well with settings with a small number of training texts. The approach to authorship verification is illustrated by exploring whether a court ruling sentence could have been written by the judge that signs it, and the approach to authorship attribution is illustrated by revisiting the authorship attribution of the Federalist papers and through a small simulation study.Peer ReviewedPostprint (author's final draft

L’estudi de la mortalitat en àrees bàsiques de salut mitjançant l’anàlisi bayesiana

Mortalitat; Anàlisi bayesiana; Àrea bàsica de salutMortalidad; Análisis bayesiano; Área básica de saludMortality; Bayesian analysis; Basic health areaAquest projecte proposa una metodologia per analitzar la variació espacial i temporal dels indicadors de mortalitat a Catalunya a escala d’àrea bàsica de salut (ABS), partint de la mortalitat anual desagregada per sexe i per grups quinquennals d’edat. Com que es parteix de taxes de mortalitat anuals i per àrees petites, les estimacions inicials dels indicadors són molt variables, i per minimitzar aquesta variabilitat sense introduir un biaix les taxes se suavitzen fent servir models jeràrquics bayesians. Aquests models incorporen l’efecte específic de cada àrea i la seva dependència espacial i temporal a través d’efectes aleatoris, i l’efecte de covariables a través d’efectes fixos, amb l’objectiu d’obtenir estimacions més robustes.Este proyecto propone una metodología para analizar la variación espacial y temporal de los indicadores de mortalidad en Cataluña a nivel de área básica de salud (ABS), partiendo de la mortalidad anual desagregada por sexo y por grupos quinquenales de edad. Como se parte de tasas de mortalidad anuales y por áreas pequeñas, las estimaciones iniciales de los indicadores son muy variables, y para minimizar esta variabilidad sin introducir un sesgo las tasas se suavizan utilizando modelos jerárquicos bayesianos. Estos modelos incorporan el efecto específico de cada área y su dependencia espacial y temporal a través de efectos aleatorios, y el efecto de co-variables a través de efectos fijos, con el objetivo de obtener estimaciones más robustas.This project proposes a methodology to analyse the spatial and temporal variation of mortality indicators in Catalonia at the basic health area (BHA) level, based on annual mortality data disaggregated by sex and five-year age groups. Since we start from annual mortality rates and by small areas, the initial estimates of the indicators are highly variable, to minimise which while avoiding introducing any bias the rates are smoothed out using Bayesian hierarchical models. These models incorporate the area-specific effect and its spatial and temporal dependence through random effects, and the effect of co-variables through fixed effects in order to obtain more robust estimates

Anàlisi de la mortalitat per tumors malignes de mama i d'estómac a Catalunya

Les diferències en la distribució geogràfica de les causes de mortalitat són una informació de gran interès per lluitar contra elles. Les primeres hipòtesis sobre les causes de moltes malalties han estat establertes a partir de la identificació d’una major freqüència d’aparició en àmbits geogràfics on hi ha presència o absència de certs factors, siguin tipus d’hàbits, alimentació, exposicions ambientals o d’altres. A més, conèixer el patró de distribució geogràfica de qualsevol causa de mort ja té valor per ell mateix, ja que pot servir de base per a la presa de decisions en l’àmbit de la gestió sanitària i salut pública, mostrant les àrees on és més prioritari intervenir, així com avaluar l’efectivitat d’algunes intervencions o programes sanitaris implantats en les diferents àrees. Per altra banda, conèixer l’evolució al llarg del temps de les causes de mortalitat aporta també una informació valuosa per identificar tendències, planificar recursos i, també, per avaluar els resultats de les accions que es van desenvolupant.Postprint (published version

Bayesian Analysis of the Heterogeneity of Literary Style

We proposed statistical analysis of the heterogeneity of literary style in a set of texts that simultaneously use different stylometric characteristics, like word length and the frequency of function words. The data set consists of several tables with the same number of rows, with the i-th row of all tables corresponding to the i-th text. The analysis proposed clusters the rows of all these tables simultaneously into groups with homogeneous style, based on a finite mixture of sets of multinomial models, one set for each table.  Different from the usual heuristic cluster analysis approaches, our method naturally incorporates the text size, the discrete nature of the data, and the dependence between categories in the analysis. The model is checked and chosen with the help of posterior predictive checks, together with the use of closed form expressions for the posterior probabilities that each of the models considered to be appropriate. This is illustrated through an analysis of the heterogeneity in Shakespeare’s plays, and by revisiting the authorshipattributionproblem of Tirant lo Blanc.Se propone un análisis estadístico para modelar la heterogeneidad delestilo literario en un conjunto de textos, para ello se utilizan simultáneamente diferentes características estilométricas, como longitud de palabra y la frecuencia de palabras función. Los datos consisten en varias tablas con el mismo número de filas, donde la fila i-ésima corresponde al texto i-ésimo. El análisis propuesto agrupa las filas de todas estas tablas simultáneamente en grupos de estilo homogéneo, en base a una mezcla finita de modelos multinomiales. El modelo propuesto tiene la ventaja sobre los análisis de conglomerados heurísticos habituales, de incorporar de forma natural el tamaño del texto, la naturaleza discreta de los datos y la dependencia entre las categorías. El modelo se selecciona y válida con la ayuda de simulaciones de la distribución predictiva a posteriori, junto con el uso de las expresiones en forma cerrada para la probabilidad a posteriori de cada uno de los modelos de mezcla considerados. Todo ello se ilustra a través de un análisis de la heterogeneidad en las obras de Shakespeare, y revisitando el problema de atribución de autoría del texto Tirant lo Blanc

Alcohol as a trigger of migraine attacks in people with migraine: results from a large prospective cohort study in English-speaking countries

Objective: To assess whether alcohol intake is associated with the onset of migraine attacks up to 2 days after consumption in individuals with episodic migraine (EM).Background: Although alcohol has long been suspected to be a common migraine trigger, studies have been inconclusive in proving this association.Methods: This was an observational prospective cohort study among individuals with migraine who registered to use a digital health platform for headache. Eligible indi-viduals were aged =18 years with EM who consumed alcohol and had tracked their headache symptoms and alcohol intake for =90 days. People who did not drink any alcohol were excluded. The association of alcohol intake (“Yes/No”) and of the number of alcoholic beverages in the 2 days preceding a migraine attack was assessed ac-counting for the presence of migraine on day-2 and its interaction with alcohol intake on day-2, and further adjusted for sex, age, and average weekly alcohol intake.Results: Data on 487 individuals reporting 5913 migraine attacks and a total of 40,165 diary days were included in the analysis. Presence of migraine on day- 2 and its interac-tion with alcohol intake on day- 2 were not significant and removed from the model. At the population level, alcohol intake on day- 2 was associated with a lower probability of migraine attack (OR [95% CI] = 0.75 [0.68, 0.82]; event rate 1006/4679, 21.5%), while the effect of alcohol intake on day- 1 was not significant (OR [95% CI] = 1.01 [0.91, 1.11]; event rate 1163/4679, 24.9%) after adjusting for sex, age, and average weekly alcohol intake. Similar results were obtained with the number of beverages as exposure.Conclusions: In this English-speaking cohort of individuals with EM who identified themselves as mostly low-dose alcohol consumers, there was no significant effect on the probability of a migraine attack in the 24 h following consumption, and a slightly lower likelihood of a migraine attack from 24 to 48 h following use.Peer ReviewedPostprint (author's final draft

Control de la velocidad de degradación de materiales compuestos para aplicacions biomédicas

En este trabajo se ha utilizado la técnica del dipping, para practicar varios tipos de recubrimientos de ácido poliláctico sobre un nuevo material compuesto totalmente biodegradable formado por PLA + vidrio de fosfato; siendo ambos materiales biodegradables, y por tanto, también el compuesto. El principio de funcionamiento que presenta este tipo de técnica es actuando como barrera física entre los fluidos biológicos y el material compuesto, protegiéndolo frente a la degradación y prolongando en el tiempo las propiedades mecánicas. El control de la velocidad de degradación se ha llevado a cabo variando el grosor y el número de capas. Mediante diversas técnicas de análisis, como los ensayos a flexión o la microscopía electrónica, se han determinado las propiedades mecánicas durante las 4 semanas que ha durado el análisis, así como los cambios morfológicos del compuesto y de la capa o capas protectoras. Los resultados mostraron cambios significativos en la morfología de los materiales después de 4 semanas de inmersión en fluido fisiológico simulado (SBF). El recubrimiento de menor espesor obtuvo los mejores resultados

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

Control de la velocidad de degradación de materiales compuestos para aplicaciones biomédicas.

En este trabajo se ha utilizado la técnica del dipping, para practicar varios tipos de recubrimientos de ácido poliláctico sobre un nuevo material compuesto totalmente biodegradable formado por PLA + vidrio de fosfato; siendo ambos materiales biodegradables, y por tanto, también el compuesto. El principio de funcionamiento que presenta este tipo de técnica es actuando como barrera física entre los fluidos biológicos y el material compuesto, protegiéndolo frente a la degradación y prolongando en el tiempo las propiedades mecánicas. El control de la velocidad de degradación se ha llevado a cabo variando el grosor y el número de capas. Mediante diversas técnicas de análisis, como los ensayos a flexión o la microscopía electrónica, se han determinado las propiedades mecánicas durante las 4 semanas que ha durado el análisis, así como los cambios morfológicos del compuesto y de la capa o capas protectoras. Los resultados mostraron cambios significativos en la morfología de los materiales después de 4 semanas de inmersión en fluido fisiológico simulado (SBF). El recubrimiento de menor espesor obtuvo los mejores resultados