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This presentation is co-financed by the European Social Fund and the state budget of the Czech Republic
Spatial Statistics of Health Data: Case Study in Olomouc Region, Czech Republic
Lukáš MAREK
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Back to the History Naples Kingdom plague map
Filippo Arrieta - 1694
Map of yellow fever in New York Published by Valentine Seaman - 1798
Map of cholera outbreak in London John Snow - 1854
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Why Geographical Information Systems?
Advanced methods for spatial analyses
Spatial statistics
Exploration of spatial pattern
Visualization and presentation for non-geographers
(doctors, specialist)
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Spatial Analyses of Health Data - AOI Disease mapping
Visual description of spatial variability of the disease incidence Maps of incidence risk, identification of areas with high risk
Geographic correlation studies Analysis of associations among the incidence and
environmental factors Analyses of spatial pattern
Exploration of spatial and spatio-temporal patterns in data Disease clusters, randomness, …
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Data Collaboration with Regional Public Health Service in
Olomouc EPIDAT database
Mandatory records about infectious diseases and patients, manually fulfilled
Age, Sex, Date, Profession, Place of residence, infection, isolation, …
2002 – 2011 > 46 000 records Anonymized
Aggregation to the regular fishnet Hexagons with the size of average cadastral unit
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
EpiDat
Infection 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Sum
Salmonella 2197 1731 1522 1706 1261 803 700 594 515 352 11381
Viral Intestinal Infections 139 194 198 197 581 476 535 396 431 689 3836
Lyme Borreliosis 226 290 180 229 319 225 274 220 237 303 2503
Tick-Borne Encephalitis 16 34 33 28 58 32 24 46 38 54 363
Unspecified Viral Encephalitis 0 3 4 4 5 5 1 3 3 2 30
Viral Meningitis 12 12 15 31 16 26 16 29 25 20 202
Varicella 1930 2247 3341 2865 1973 3529 1904 3057 2623 2910 26379
Hepatitis A 5 11 11 12 6 6 152 66 49 50 368
Acute Hepatitis B 30 14 22 20 14 6 18 5 4 2 135
Parotitis 5 7 1 18 356 126 115 120 227 7 982
Sum 4560 4543 5327 5110 4589 5234 3739 4536 4152 4389 46179
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Software
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Choropleth mapping One of the most
common type of map Densities rather than
continuously distributed values
Visual tool for the analysis of spatial distribution of phenomenon
Relative values
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Identification of Spatial Processes Estimation of the nature of phenomenon Plenty of methods
Graphical Numerical
Testing of Complete Spatial Randomness Or other spatial processes
Scale dependency
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Graphical methods Morishita index plot
index of spatial aggregation for a spatial point pattern
Fry (Patterson) plot Scatterplot of the vector differences xj − xi between all pairs of
distinct points in the pattern
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Graphical methods Quadrat analysis
Quadrat count Visual evaluation
Quadrat test χ2 dispersion test of Complete
Spatial Randomness 506 tiles, χ2 = 11065.02, df = 505, p-
value < 2.2e-16
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Graphical methods Ripley‘s K-function
Reduced second moment function Mean number of points within distance from an arbitrary point Comparing (testing) to simulated CSR L-function
Scaled K-function
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Graphical methods Kernel density
Nonparametric statistical method for estimating the probability of a defined event
Intensity of the phenomenon in space Density map reveals the spatial clusters
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Global and Local Spatial „Clustering“ Exploring of the spatial autocorrelation More location based then attribute – position based Overview of global situation in entire area Moran‘s I, Getis Ord General G, …
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Local analyses E.g. LISA
Local indicators of spatial associations
Position of identified clusters Statistical significancy Intensity and type of clustering
Local Moran's I, Getis-Ord Gi*, Kuldorff‘s scan, Diggle‘s test, …
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Multivariate Clustering Similarity searching in
attribute space Classification of areas with
related properties of occuring diseases and their parameters
Classification of similar cases
Without spatial relations
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Problems / Challenges Geocoding Aggregation Neighbourhood estimation Modifiable areal unit problem Probability distribution of the disease occurrence Underlying processes Under / Overestimation of results leading to
misinterpretation Age / Population standardization
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Future work Spatio-temporal analysis Bayesian modelling and smoothing Multivariate statistics with spatial relations Neural networks for clustering GWR, GLMM
First InDOG Doctoral Conference, 29th October - 1st November 2012, Olomouc
Thank you for your attention
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