Spatial pattern in prevalence of paratuberculosis infection diagnosed with misclassification in Danish dairy herds in 2009 & 2013
The objective of this study was to identify the spatial pattern in infection prevalence, when results were adjusted for covariate information and diagnostic misclassification. Furthermore, we compared the estimated spatial pattern with the spatial pattern obtained without adjustment for misclassification. The study included 1242 herds in 2009 and 979 herds in 2013. The within-herd prevalence was modelled using a hierarchical logistic regression model and included a spatial component modelled by a continuous Gaussian field. The Stochastic Partial Differential Equation (SPDE) approach and Integrated Nested Laplace Approximat...
Source: Spatial and Spatio-temporal Epidemiology - December 11, 2015 Category: Epidemiology Source Type: research

Spatial and socio-economic effects on malaria morbidity in children under 5 years in Malawi in 2012
Conclusion This study showed that malaria is a disease of poverty. Enhanced vegetation index was an important factor in malaria morbidity. The central region was identified as the area with greatest disease burden. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - December 11, 2015 Category: Epidemiology Source Type: research

Small area clustering of under-five children's mortality and associated factors using geo-additive Bayesian discrete-time survival model in Kersa HDSS, Ethiopia
Conclusion : This study reveals geographic patterns in rates of Under-five mortality in those selected small administrative regions and shows some important determinants of under-five mortality. More importantly, we observed clustering of under-five mortality, which indicates the importance of spatial effects and presentation of this clustering through maps that facilitates visuality and highlights differentials across geographical areas that would, otherwise, be overlooked in traditional data-analytic methods. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - December 11, 2015 Category: Epidemiology Source Type: research

Hierarchical spatial modelling of pneumonia prevalence when response outcome has misclassification error: applications to household data from Malawi
Publication date: Available online 1 December 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Lawrence N. Kazembe, Mphatso S. Kamndaya Pneumonia remains a major cause of child mortality in less developed countries. However, the accuracy of its prevalence and burden remains a challenge because disease data is often based on self-reports, resulting in measurement error in a form of under- and over-reporting. We propose hierarchical disease mapping approaches that permit measurement error, through different prior distributions of sensitivity and specificity. Proposed models were used to evaluate spatial va...
Source: Spatial and Spatio-temporal Epidemiology - December 11, 2015 Category: Epidemiology Source Type: research

An integrated Bayesian model for estimating the long-term health effects of air pollution by fusing modelled and measured pollution data: A case study of nitrogen dioxide concentrations in Scotland
Publication date: Available online 2 October 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Guowen Huang, Duncan Lee, Marian Scott The long-term health effects of air pollution can be estimated using a spatio-temporal ecological study, where the disease data are counts of hospital admissions from populations in small areal units at yearly intervals. Spatially representative pollution concentrations for each areal unit are typically estimated by applying Kriging to data from a sparse monitoring network, or by computing averages over grid level concentrations from an atmospheric dispersion model. We pro...
Source: Spatial and Spatio-temporal Epidemiology - October 3, 2015 Category: Epidemiology Source Type: research

Comparing Children’s GPS Tracks with Geospatial Proxies for Exposure to Junk Food
This study conducts a GIS-based analysis of GPS tracks—‘activity spaces’—and 21 proxies for activity spaces (e.g. buffers, container approaches) for a sample of 526 children (ages 9-14) in London, Ontario, Canada. These measures are combined with a validated food environment database (including fast food and convenience stores) to create a series of junk food exposure estimates and quantify the errors resulting from use of different proxy methods. Results indicate that exposure proxies consistently underestimate exposure to junk foods by as much as 68%. This underestimation is important to policy de...
Source: Spatial and Spatio-temporal Epidemiology - October 2, 2015 Category: Epidemiology Source Type: research

Comparing INLA and OpenBUGS for hierarchical Poisson modeling in disease mapping
Publication date: Available online 11 August 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): R. Carroll, A.B. Lawson, C. Faes, R.S. Kirby, M. Aregay, K. Watjou The recently developed R package INLA (Integrated Nested Laplace Approximation) is becoming a more widely used package for Bayesian inference. The INLA software has been promoted as a fast alternative to MCMC for disease mapping applications. Here, we compare the INLA package to the MCMC approach by way of the BRugs package in R, which calls OpenBUGS. We focus on the Poisson data model commonly used for disease mapping. Ultimately, INLA is a ...
Source: Spatial and Spatio-temporal Epidemiology - August 12, 2015 Category: Epidemiology Source Type: research

Space–time airborne disease mapping applied to detect specific behaviour of varicella in Valencia, Spain
Publication date: July–October 2015 Source:Spatial and Spatio-temporal Epidemiology, Volumes 14–15 Author(s): Adina Iftimi, Francisco Montes, Ana Míguez Santiyán, Francisco Martínez-Ruiz Airborne diseases are one of humanity’s most feared sicknesses and have regularly caused concern among specialists. Varicella is an airborne disease which usually affects children before the age of 10. Because of its nature, varicella gives rise to interesting spatial, temporal and spatio-temporal patterns. This paper studies spatio-temporal exploratory analysis tools to detect specific behaviou...
Source: Spatial and Spatio-temporal Epidemiology - July 31, 2015 Category: Epidemiology Source Type: research

Space-time airborne disease mapping applied to detect specific behaviour of varicella in Valencia, Spain
Publication date: Available online 22 July 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Adina Iftimi, Francisco Montes, Ana Míguez Santiyán, Francisco Martínez-Ruiz Airborne diseases are one of humanity’s most feared sicknesses and have regularly caused concern among specialists. Varicella is an airborne disease which usually affects children before the age of 10. Because of its nature, varicella gives rise to interesting spatial, temporal and spatio-temporal patterns. This paper studies spatio-temporal exploratory analysis tools to detect specific behaviour of varicella ...
Source: Spatial and Spatio-temporal Epidemiology - July 22, 2015 Category: Epidemiology Source Type: research

Using lung cancer mortality to indirectly approximate smoking patterns in space
Publication date: Available online 13 July 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Verena Jürgens , Silvia Ess , Matthias Schwenkglenks , Thomas Cerny , Penelope Vounatsou Smoking is the leading cause of lung cancer. Non-smoking factors have been associated with the disease. Existing Swiss survey data only capture the country partially and temporal coverage does not allow for a time lag between exposure to tobacco and lung cancer outbreak. Knowledge about the distribution of tobacco-use is essential to estimate its contribution to disease burden. Bayesian regression models were applied to est...
Source: Spatial and Spatio-temporal Epidemiology - July 13, 2015 Category: Epidemiology Source Type: research

Accounting for spatial effects in land use regression for urban air pollution modeling
Publication date: July–October 2015 Source:Spatial and Spatio-temporal Epidemiology, Volumes 14–15 Author(s): Stefania Bertazzon , Markey Johnson , Kristin Eccles , Gilaad G. Kaplan In order to accurately assess air pollution risks, health studies require spatially resolved pollution concentrations. Land-use regression (LUR) models estimate ambient concentrations at a fine spatial scale. However, spatial effects such as spatial non-stationarity and spatial autocorrelation can reduce the accuracy of LUR estimates by increasing regression errors and uncertainty; and statistical methods for resolving these effec...
Source: Spatial and Spatio-temporal Epidemiology - July 11, 2015 Category: Epidemiology Source Type: research

Accounting for spatial effects in land use regression for urban air pollution modelling
Publication date: Available online 2 July 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Stefania Bertazzon , Markey Johnson , Kristin Eccles , Gilaad G. Kaplan In order to accurately assess air pollution risks, health studies require spatially resolved pollution concentrations. Land-use regression (LUR) models estimate ambient concentrations at a fine spatial scale. However, spatial effects such as spatial non-stationarity and spatial autocorrelation can reduce the accuracy of LUR estimates by increasing regression errors and uncertainty; and statistical methods for resolving these effects - e.g., spati...
Source: Spatial and Spatio-temporal Epidemiology - July 2, 2015 Category: Epidemiology Source Type: research

Does Primary Biliary Cirrhosis cluster in time?
We examined whether a temporally varying environmental agent may be involved by analysing population-based PBC data from northeast England over 1987-2003. Using an adaptation of a method proposed by Potthoff and Whittinghill, we found significant temporal variation by date of diagnosis at the level of aggregation of one year. However, there was no evidence for general irregular (non-seasonal) temporal clustering within periods less than a year. These results provide little support for the involvement of agents occurring in geographically widespread mini-epidemics, but – taken together with studies of spatial and spat...
Source: Spatial and Spatio-temporal Epidemiology - June 16, 2015 Category: Epidemiology Source Type: research

A novel approach to mapping and calculating the rate of spread of endemic bovine tuberculosis in England and Wales
Publication date: Available online 23 May 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): L.A. Brunton , R. Nicholson , A. Ashton , N. Alexander , W. Wint , G. Enticott , K. Ward , J.M. Broughan , A.V. Goodchild A mathematical method for estimating the endemic status of bovine tuberculosis (bTB) in cattle in England and Wales has been developed. 6.25km2 hexagonal cells were used as the base resolution. Maps were produced for overlapping two-year periods spanning 2001/03 to 2009/11. Distance from a farm to the ten nearest ‘Officially Tuberculosis Free status – Withdrawn’ incidents within ...
Source: Spatial and Spatio-temporal Epidemiology - May 24, 2015 Category: Epidemiology Source Type: research

Do people really know what food retailers exist in their neighborhood? Examining GIS-based and perceived presence of retail food outlets in an eight-county region of South Carolina
This study has implications for how researchers measure the food environment. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - May 9, 2015 Category: Epidemiology Source Type: research

Sources of spatial animal and human health data: Casting the net wide to deal more effectively with increasingly complex disease problems
Publication date: Available online 8 May 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Kim B. Stevens , Dirk U. Pfeiffer During the last 30 years it has become commonplace for epidemiological studies to collect locational attributes of disease data. Although this advancement was driven largely by the introduction of handheld global positioning systems (GPS) and more recently, smartphones and tablets with built-in GPS, the collection of georeferenced disease data has moved beyond the use of handheld GPS devices and there now exist numerous sources of crowdsourced georeferenced disease data such as that a...
Source: Spatial and Spatio-temporal Epidemiology - May 8, 2015 Category: Epidemiology Source Type: research

Assessing environmental inequalities in ambient air pollution across urban Australia
Publication date: April 2015 Source:Spatial and Spatio-temporal Epidemiology, Volume 13 Author(s): Luke D. Knibbs , Adrian G. Barnett Identifying inequalities in air pollution levels across population groups can help address environmental justice concerns. We were interested in assessing these inequalities across major urban areas in Australia. We used a land-use regression model to predict ambient nitrogen dioxide (NO2) levels and sought the best socio-economic and population predictor variables. We used a generalised least squares model that accounted for spatial correlation in NO2 levels to examine the associations be...
Source: Spatial and Spatio-temporal Epidemiology - April 28, 2015 Category: Epidemiology Source Type: research

Spatial quantile regression using INLA with applications to childhood overweight in Malawi
Publication date: Available online 18 April 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Owen P.L. Mtambo , Salule J. Masangwi , Lawrence N.M. Kazembe Analyses of childhood overweight have mainly used mean regression. However, using quantile regression is more appropriate as it provides flexibility to analyse the determinants of overweight corresponding to quantiles of interest. The main objective of this study was to fit a Bayesian additive quantile regression model with structured spatial effects for childhood overweight in Malawi using the 2010 Malawi DHS data. Inference was fully Bayesian using R-I...
Source: Spatial and Spatio-temporal Epidemiology - April 28, 2015 Category: Epidemiology Source Type: research

Spatial variation in attributable risks
Publication date: Available online 24 February 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): Peter Congdon The attributable risk (AR) measures the contribution of a particular risk factor to a disease, and allows estimation of disease rates specific to that risk. While previous studies consider variability in ARs over demographic categories, this paper considers the extent of spatial variability in ARs estimated from multilevel data with confounders both at individual and geographic levels. A case study considers the AR for diabetes in relation to elevated BMI, and area rates for diabetes attributable t...
Source: Spatial and Spatio-temporal Epidemiology - February 24, 2015 Category: Epidemiology Source Type: research

Estimating areas of common risk in low birth weight and infant mortality in Namibia: a joint spatial analysis at sub-regional level
Publication date: Available online 13 February 2015 Source:Spatial and Spatio-temporal Epidemiology Author(s): L. Kazembe , N-B. Kandala There is lots of literature documenting a positive association between low birth weight (LBW) and infant mortality (IM), however, little is known how the risk of LBW and IM are geographically co-distributed. We fitted joint spatial models of LBW and IM, and used data from Namibia, to examine their geographical variability. We used a Bayesian approach to measure and rank areas according to specific and shared risk of LBW and IM. Our findings show some degree of similarities in the spatia...
Source: Spatial and Spatio-temporal Epidemiology - February 15, 2015 Category: Epidemiology Source Type: research

Maternal Anemia Associated with Walkable Distance to Healthy Food Sources in Bronx, New York
Publication date: Available online 29 December 2014 Source:Spatial and Spatio-temporal Epidemiology Author(s): Danielle M. Bottalico , Glen D. Johnson , Cynthia Chazotte , Chavi Eve Karkowsky The relationship between walkable access to healthy food sources and risk of anemia in pregnancy was evaluated for a cohort of 4678 women who initiated prenatal care in the year 2010 at an academic medical center in Bronx, New York. After geocoding patient residences, street network distances were obtained for the closest healthy food sources, which were identified from multiple databases. For lower-income patients, as indicated by ...
Source: Spatial and Spatio-temporal Epidemiology - December 30, 2014 Category: Epidemiology Source Type: research

Space-time confounding adjusted determinants of child HIV/TB mortality for large zero-inflated data in rural South Africa
Publication date: December 2011 Source:Spatial and Spatio-temporal Epidemiology, Volume 2, Issue 4 Author(s): Eustasius Musenge , Penelope Vounatsou , Kathleen Kahn South Africa is experiencing a major burden of HIV/TB. We used longitudinal data from the Agincourt sub-district in rural northeast South Africa over the years 2000 to 2005. A total of 187 HIV/TB deaths were observed among 16,844 children aged 1–5years coming from 8,863 households. In this paper we used Bayesian models to assess risk factors for child HIV/TB mortality taking into account the presence of spatial correlation. Bayesian zero inflated spatio...
Source: Spatial and Spatio-temporal Epidemiology - December 4, 2014 Category: Epidemiology Source Type: research

Immigrant maternal depression and social networks. A multilevel Bayesian spatial logistic regression in South Western Sydney, Australia
Publication date: September 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 6 Author(s): John G. Eastwood , Bin B. Jalaludin , Lynn A. Kemp , Hai N. Phung , Bryanne EW Barnett The purpose is to explore the multilevel spatial distribution of depressive symptoms among migrant mothers in South Western Sydney and to identify any group level associations that could inform subsequent theory building and local public health interventions. Migrant mothers (n =7256) delivering in 2002 and 2003 were assessed at 2–3weeks after delivery for risk factors for depressive symptoms. The binary outcome variables were Ed...
Source: Spatial and Spatio-temporal Epidemiology - December 4, 2014 Category: Epidemiology Source Type: research

Spatio-temporal clustering of the incidence of schizophrenia in Quebec, Canada from 2004 to 2007
In this study, we present a spatio-temporal analysis of the incidence of schizophrenia in Quebec from 2004 to 2007 using administrative databases from the Régie de l’Assurance Maladie du Quebec and the hospital discharge database. We conducted purely spatial analyses for each age group adjusted by sex for the whole period using SatScan (version 9.1.1). Findings from the study indicated variations in the spatial clustering of schizophrenia according to sex and age. In term of incidence rate, there are high differences between urban and rural-remote areas, as well as between the two main metropolitan areas of th...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Multivariate bayesian spatial model of preterm birth and cardiovascular disease among georgia women: Evidence for life course social determinants of health
Conclusion: Modest evidence for spatial structure of the ecologic correlation of PTB and women’s CVD is consistent with a lifecourse perspective on socially clustered determinants of health. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Spatiotemporal patterns of infant bronchiolitis in a Tennessee Medicaid population
Publication date: September 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 6 Author(s): Chantel D. Sloan , Tebeb Gebretsadik , Pingsheng Wu , Kecia N. Carroll , Edward F. Mitchel , Tina V. Hartert Respiratory syncytial virus (RSV) is a major cause of worldwide morbidity and mortality in infants, primarily through the induction of bronchiolitis. RSV epidemics are highly seasonal, occurring in the winter months in the northern hemisphere. Within the United States, RSV epidemic dynamics vary both spatially and temporally. This analysis employs a retrospective space–time scan statistic to locate spatiotem...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Random property allocation: A novel geographic imputation procedure based on a complete geocoded address file
Publication date: September 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 6 Author(s): Scott R. Walter , Nectarios Rose Allocating an incomplete address to randomly selected property coordinates within a locality, known as random property allocation, has many advantages over other geoimputation techniques. We compared the performance of random property allocation to four other methods under various conditions using a simulation approach. All methods performed well for large spatial units, but random property allocation was the least prone to bias and error under volatile scenarios with small units and low ...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Prostate cancer incidence in light of the spatial distribution of another screening-detectable cancer
Publication date: September 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 6 Author(s): David I. Gregorio , Holly Samociuk Bias in spatial analyses that overlook compositional and contextual factors of communities can be substantial. We first examined spatial patterns among 11,728 prostate cancer cases across Connecticut, 1994–98. A spatial scan statistic (SatScan™) identified two locations where average annual incidence rates significantly exceeded the statewide level and two locations with significantly lower disease rates. Extending the analysis to adjust rates for age and race/ethnicity grea...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Spatial and spatio-temporal models with R-INLA
Publication date: December 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 7 Author(s): Marta Blangiardo , Michela Cameletti , Gianluca Baio , Håvard Rue During the last three decades, Bayesian methods have developed greatly in the field of epidemiology. Their main challenge focusses around computation, but the advent of Markov Chain Monte Carlo methods (MCMC) and in particular of the WinBUGS software has opened the doors of Bayesian modelling to the wide research community. However model complexity and database dimension still remain a constraint. Recently the use of Gaussian random fields has become ...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Erratum to “Spatial and spatio-temporal models with R-INLA” [Spat Spatio-tempor Epidemiol 4 (2013) 33–49]
Publication date: December 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 7 Author(s): Marta Blangiardo , Michela Cameletti , Gianluca Baio , Håvard Rue (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Estimation of malaria incidence in northern Namibia in 2009 using Bayesian conditional-autoregressive spatial–temporal models
Publication date: December 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 7 Author(s): Victor A. Alegana , Peter M. Atkinson , Jim A. Wright , Richard Kamwi , Petrina Uusiku , Stark Katokele , Robert W. Snow , Abdisalan M. Noor As malaria transmission declines, it becomes increasingly important to monitor changes in malaria incidence rather than prevalence. Here, a spatio-temporal model was used to identify constituencies with high malaria incidence to guide malaria control. Malaria cases were assembled across all age groups along with several environmental covariates. A Bayesian conditional-autoregressive ...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

How to choose geographical units in ecological studies: Proposal and application to campylobacteriosis
In this study, we proposed and applied a set of measurable criteria applicable for orienting the choice of geographical unit. Nine criteria were selected, covering many aspects such as biological relevance, communicability of results, ease of data access, distribution of exposure variables, cases and population, and shape of unit. These criteria were then applied to compare various geographical units derived from administrative, health services, and natural frameworks that could be used for the study of the spatial distribution of campylobacteriosis in the province of Quebec, Canada. In this study, municipality was the geo...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Exploring hotspots of pneumococcal pneumonia and potential impacts of ejecta dust exposure following the Christchurch earthquakes
Publication date: December 2013 Source:Spatial and Spatio-temporal Epidemiology, Volume 7 Author(s): Amber L. Pearson , Simon Kingham , Peter Mitchell , Philippe Apparicio The etiology of pneumococcal pneumonia (PP) is well-known. Yet, some events may increase its incidence. Natural disasters may worsen air quality, a risk factor for PP. We investigated spatial/spatio-temporal clustering of PP pre- and post-earthquakes in Christchurch, New Zealand. The earthquakes resulted in deaths, widespread damage and liquefaction ejecta (a source of air-borne dust). We tested for clusters and associations with ejecta, using 97 cases...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Accuracy of prospective space–time surveillance in detecting tuberculosis transmission
Publication date: April 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 8 Author(s): Aman Verma , Kevin Schwartzman , Marcel A. Behr , Alice Zwerling , Robert Allard , Christian M. Rochefort , David L. Buckeridge To improve detection of tuberculosis transmission, public health can supplement contact tracing with space–time surveillance. However, investigation of space–time clusters not due to transmission (false alarms), may lead to costly, unnecessary interventions. We measured the accuracy of prospective space–time surveillance in detecting tuberculosis transmission, assessing the number ...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

The spread process of epidemic influenza in the continental United States, 1968–2008
Publication date: April 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 8 Author(s): Bianca L. Malcolm Understanding the quantitative disease dynamics of influenza is important in developing strategies to control its spread. This research analyzed the dominant spread process of epidemic influenza in the continental United States over a 41-year period. Spatial autocorrelation and simple correlation were applied to pneumonia and influenza mortality to observe the effect of distance and population on the between-state transmission of seasonal influenza. Annual influenza epidemics exhibited distance-based spatia...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Characterizing urban vulnerability to heat stress using a spatially varying coefficient model
This study combines excess non-accidental mortality counts, numerical weather simulations, US Census and parcel data into an assessment of vulnerability to heat in Houston, Texas. Specifically, a hierarchical model with spatially varying coefficients is used to account for differences in vulnerability among census block groups. Socio-economic and demographic variables from census and parcel data are selected via a forward selection algorithm where at each step the remaining variables are orthogonalized with respect to the chosen variables to account for collinearity. Daily minimum temperatures and composite heat indices (e...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Analysis of spatial variations in the effectiveness of graduated driver’s licensing (GDL) program in the state of Michigan
This article reports on the development of spatial statistical modeling approaches to evaluate and compare the effectiveness of GDL policy across eighty-three counties in the state of Michigan. Data were gathered from several publicly available databases, including the US Fatality Analysis Reporting System (FARS), US Census Bureau, US Bureau of Labor Statistics, and US Department of Agriculture. To account for spatial dependence among crash counts from adjacent counties we invoke spatial random effects, which we provide with a Conditionally AutoRegressive (CAR) prior. Our analysis confirms previous findings that GDL in Mic...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Generalizing the spatial relative risk function
Publication date: April 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 8 Author(s): W.T.P. Sarojinie Fernando , Martin L. Hazelton The spatial relative risk function is defined as the ratio of densities describing respectively the spatial distribution of cases and controls. It has proven to be an effective tool for visualizing spatial variation in risk in many epidemiological applications over the past 20years. We discuss the generalization of this function to spatio-temporal case-control data, and also to situations where there are covariates available that may affect the spatial patterns of disease. We ex...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

A comparison between self-reported and GIS-based proxies of residential exposure to environmental pollution in a case–control study on lung cancer
Publication date: June 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 9 Author(s): M. Cordioli , A. Ranzi , A. Freni Sterrantino , L. Erspamer , G. Razzini , U. Ferrari , M.G. Gatti , K. Bonora , F. Artioli , C.A. Goldoni , P. Lauriola In epidemiological studies both questionnaire results and GIS modeling have been used to assess exposure to environmental risk factors. Nevertheless, few studies have used both these techniques to evaluate the degree of agreement between different exposure assessment methodologies. As part of a case–control study on lung cancer, we present a comparison between self-repo...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

A space-time point process model for analyzing and predicting case patterns of diarrheal disease in northwestern Ecuador
Publication date: June 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 9 Author(s): Jaeil Ahn , Timothy D. Johnson , Darlene Bhavnani , Joseph N.S. Eisenberg , Bhramar Mukherjee We consider modeling case-patterns under a complex spatial and longitudinal sampling design as conducted via a serial case–control study of diarrheal disease in northwestern Ecuador. We build a two-stage space-time model to understand the role of spatially and temporally referenced covariates that reflect social and natural environments in the sampled region, after accounting for unmeasured residual heterogeneities. All diarrhe...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Spatial patterns of human papillomavirus-associated cancers within the state of Minnesota, 1998–2007
This study analyzed the spatial dependence and pattern of HPV-associated cancers in Minnesota from 1998 to 2007 using sparse spatial generalized linear mixed models and scan statistics for cluster detection. A strong clustering pattern was seen in the northern region of Minnesota for both men and women. Separate cluster analyses by gender identified areas of overlapping disease burden. The patterns observed in this analysis demonstrate the need to account for spatial dependence when analyzing disease rates for geographic areas (i.e. county or ZIP codes) since spatial analyses of HPV-associated cancers have the potential to...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Spatial correlation in Bayesian logistic regression with misclassification
This study presents Bayesian logistic regression with adjustment for misclassification of the outcome applied to data with spatial correlation. The models assessed include a fixed effects model, an independent random effects model, and models with spatially correlated random effects modelled using conditional autoregressive prior distributions (ICAR and ICAR( ρ )). Performance of these models was evaluated in a simulation study. Parameters were estimated by Markov Chain Monte Carlo methods, using slice sampling to improve convergence. The results demonstrated that adjustment for misclassification must be included to pr...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

The choice of spatial scales and spatial smoothness priors for various spatial patterns
This article addresses two consequent issues: the choice of the spatial smoothness prior and the scale of the grid. Firstly, we describe several spatial smoothness priors applicable for grid data and discuss the contexts in which these priors can be employed based on different aims. Two such aims are considered, i.e., to identify regions with clustering and to model spatial dependence in the data. Secondly, the choice of the grid size is shown to depend largely on the spatial patterns. We present a guide on the selection of spatial scales and smoothness priors for various point patterns based on the two aims for spatial sm...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Spatio-temporal variability of bovine tuberculosis eradication in Spain (2006–2011)
In this study we analyzed the space–time variation of the risk of bovine tuberculosis (bTB) in cattle between 2006 and 2011. The results indicated that at country level, there were no significant temporal changes between years, but, at county level bTB evolution was more heterogeneous. In some counties, between some years, the prevalence and the incidence of the disease was higher as compared to the global rate in the rest of the counties of Spain. The analysis of potential risk factors indicated that both, a large number of movements from counties with high incidence (>1%), and presence of bullfighting cattle...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Assessing the impact of selective migration and care homes on geographical inequalities in health – A total population cohort study in Sheffield
We examined for evidence of selective migration and assessed the contribution of migration to observed mortality gradients. We used a total population cohort (539737 in 2001), linked mortality data (2001–2010) and linked data from a health survey carried out in 2000 (66% response rate yielding 10185 responses). We used lower super-output areas and electoral wards as the spatial units of analysis. We found clear evidence of selective migration. In the 25–44 age band, relative risks of mortality were 1.71 (95% CI 1.37–2.12) in migrants from low to high deprivation areas compared with people remaining in low...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Assessment of land use factors associated with dengue cases in Malaysia using Boosted Regression Trees
This study aims to clarify if land use factors other than human settlements, e.g. different types of agricultural land use, water bodies and forest are associated with reported dengue cases from 2008 to 2010 in the state of Selangor, Malaysia. From the correlative relationship, we aim to generate a prediction risk map. We used Boosted Regression Trees (BRT) to account for nonlinearities and interactions between the factors with high predictive accuracies. Our model with a cross-validated performance score (Area Under the Receiver Operator Characteristic Curve, ROC AUC) of 0.81 showed that the most important land use factor...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Using geographical information systems and cartograms as a health service quality improvement tool
Discussion This methodology provides a technique for combining simple GIS tools to create a novel output, CartIS, in a health service context with the key aim of improving visualisation communication techniques which highlight variation in small scale geographies across large regions. CartIS more faithfully represents the data than interpolation, and visually highlights areas of extreme value more than cartograms, when either is used in isolation. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Real geographies and virtual landscapes: Exploring the influence on place and space on mortality Lexis surfaces using shaded contour maps
Publication date: July 2014 Source:Spatial and Spatio-temporal Epidemiology, Volume 10 Author(s): Jonathan Minton This paper describes how shaded contour plots, applied to mortality data from the Human Mortality Database, can be used to compare between nations, and start to tease out some of the ways that place and space matters. A number of shaded contour plots are presented, in order to describe the age, period and cohort effects which are apparent within them. They show variations between different subpopulations within the same nation, over time, and between nations. In illustrating these intra- and international var...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

Bayesian tracking of emerging epidemics using ensemble optimal statistical interpolation
We present a preliminary test of the Ensemble Optimal Statistical Interpolation (EnOSI) method for the statistical tracking of an emerging epidemic, with a comparison to its popular relative for Bayesian data assimilation, the Ensemble Kalman Filter (EnKF). The spatial data for this test was generated by a spatial susceptible-infectious-removed (S-I-R) epidemic model of an airborne infectious disease. Both tracking methods in this test employed Poisson rather than Gaussian noise, so as to handle epidemic data more accurately. The EnOSI and EnKF tracking methods worked well on the main body of the simulated spatial epidemic...
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research

A spatio-temporal model for estimating the long-term effects of air pollution on respiratory hospital admissions in Greater London
We present a new model for estimating the effects of air pollution on human health, which allows for residual spatio-temporal autocorrelation, and a study into the long-term effects of air pollution on human health in Greater London, England. The individual and joint effects of different pollutants are explored, via the use of single pollutant models and multiple pollutant indices. (Source: Spatial and Spatio-temporal Epidemiology)
Source: Spatial and Spatio-temporal Epidemiology - November 20, 2014 Category: Epidemiology Source Type: research