Recent Advances in Geodesy and Geomatics Engineering Health Datasets in Spatial Analyses: What We Want, What We Get and What We Can Use LUKÁŠ MAREK*, JIŘÍ DVORSKÝ, VÍT PÁSZTO, PAVEL TUČEK, ALEŠ VÁVRA Department of Geoinformatics, Faculty of Science Palacky University in Olomouc 17. listopadu 50, Olomouc, 771 46 CZECH REPULIC *[email protected] http:// http://www.geoinformatics.upol.cz/ Abstract: One of main aims of the spatial analysis of health and medical datasets is to provide additional information in the specialized medical research. These analyses can be used for disease mapping; searching for places with the higher intensity and probability of the disease occurrence; or the influence assessment of selected natural or artificial phenomena. While the space is obviously a crucial component within spatial analysis, it is also a very problematic part in geospatial research of health data. The following contribution aims to presents the current situation of providing (mainly public) health data sets in the Czech Republic and the usability of data for geoanalyses. Simultaneously, the issue of the anonymization methods of these highly private data is discussed, as they are one of frequently used by data providers. Last part is dealing with the form of results, which should be as precise as it is possible on one hand, but it should not reveal any private or sensitive data than it is necessary. Key-Words: Spatial analyses, health data, private information, anonymization, re-identification, visualization, data providers, disease mapping. 1 Introduction Republic. The paper starts with the information While one part of geoscientists considers about data providers and it continues with terms and geographical information systems (GIS) to be the conditions, which need to be fulfilled due to the highest level of geosciences, the other part thinks usage of data in analyses. Then the form of data and about GIS as the tool, which allows the penetration their possibilities of manipulations, analytical of geosciences into different branches of the science procedures and visualizations are presented, while and the great possibility for highly interdisciplinary the emphasis is to the anonymization of the data. All studies [8]. statements are supported by examples with real data The literature often uses phrases such as sets. geographical epidemiology, spatial epidemiology, medical geography or even geomedicine that 2 Data describe dynamic body of the theory and analytic Data and suitable analytical methods are the most methods concerned with the study of spatial important component of any successful research analyses of the disease incidence and mortality [16]. task or case study. Health and medical data require One of main aims of the spatial analysis of health specific procedures of the management, presentation and medical datasets is to provide additional and operations, which emerge from the information in the specialized medical research. confidentiality of data. It means that data are usually These analyses can be used for disease mapping; provided in the aggregated or anonymized form; or searching for places with the higher intensity and as incomplete data sets – mainly in the sense of probability of the disease occurrence; or the missing correct and complete addresses of explored influence assessment of selected natural or artificial cases. These data types need to be analyzed by phenomena. While the space is obviously a crucial suitable analytical procedures, while the uncertainty component within spatial analysis, it is also a very and the inaccuracy of data characteristics need to be problematic part in geospatial research of health taken into account. data. The elementary classification of the data could The contribution aims to present several initial contain the following pair: 1) point data sets - with steps common in spatial research of medical data. It the direct location (the place of infection, the is focused mainly on the current state in the Czech patient’s home address, etc.) and 2) aggregated ISBN: 978-960-474-335-3 240 Recent Advances in Geodesy and Geomatics Engineering frequency data – they can be based on the accessibility. The outstanding summary of existing administrative units or grids. Examples of world sources of health data sets with the emphasis environmental variables relevant to epidemiological on the cancer research can be found e.g. in [14]. Let analysis are shown in the Table 1. A comprehensive us mention at least international organizations ˗ data classification can be found e.g. in [2], where WHO (World Health Organization), EUROSTAT or data are sorted with regards to their origin and the OECD (Organization for Economic Cooperation purpose as follows: and Development), which have the vast amount of • Irregular lattice data – measures collected statistical data including the health and aggregated/averaged to the level of census medical problematic. Furthermore, the INSPIRE tracts or other type of administrative district. directive (Infrastructure for Spatial Information in • Case-event data – locations of individual Europe) contains theme called Human health and cases of a disease, or of individual members safety that is a part of the Annex III. It deals with of a suitable control group, or covariates. topics ranging from allergies through the diseases • Geostatistical data – measurements sampled occurrence to the quality of the environment. at point locations. The description of three main Czech providers of • Regular lattice data – measures the medical and health data follows. They make aggregated/averaged to a regular grid their data sets publicly accessible in form of tables, (typically arising from remote sensing). reports, journals or annuals – all in the analogue and digital form of sources. Table 1. Examples of spatial data usable for the The biggest provider is the Institute of Health epidemiological studies (according to [12]). Information and Statistics of the Czech Republic Generic type Variables (http://www.uzis.cz/). The Institute is a component of the State Statistical Service (on the basis of the Location Longitude, latitude competence act) and performs this activity Anthropogenic Distance to roads Distance to city lights according to Act no. 89/1995 Sb. - On national Demographic Human population statistical service, in wording of later regulations. It Topographic Elevation cooperates with organs of State Statistical Service, Land cover NDVI ) mainly with Czech Statistical Office. It secures Temperature Land surface temperature connection between NHIS and individual health Air temperature care providers and also cooperates with the Middle infrared reflectance information systems operators of other Water and organizations inside and outside the health sector. Vapor pressure deficit moisture The Institute cooperates with associations of Distance to rivers hospitals, associations of physicians, professional Cold cloud duration medical societies, health insurance companies and Potential evapotranspiration other organizations. The collaboration is mostly General Modeled length of growing period dealing with precise specifications of the NHIS climatic contents and the utilization of the collected data. The Institute also cooperates on the international 2.1 Providers of Publicly Available Data level of health statistics - particularly with WHO, Primary data collected by local, regional and OECD, the UN, EUROSTAT and other national health institutes have also the meaningful organizations. The Institute is the official presenter significance for analysts, but they have not been of NHIS data for the Czech Republic. The Institute mentioned before. Table 1 does not contain the manages extensive amount of data in the several complete list of all relevant data sources and data scales (local - national) but publicly available is just sets (that is hardly possible to create), which could fragment of databases mainly in the Data be significant for the occurrence of diseases or Presentation System and several registers [15]. health problems of the population. However, it The second provider of health data is the Czech provides a partial overview that at least allows the Statistical Office (http://www.czso.cz/). The Czech creation of the image about the amount of currently Statistical Office (CZSO) is a central body of the available data sets for the selected case study. state administration of the Czech Republic. It was That is the reason why the common statement established on 8 January 1969 by the Act No 2/1969 about the deficiency of health data sets is not fully Sb., passed by the Czech National Council, on true. The question should not be about the existence establishment of ministries and other institutions of of the data, but about their availability and the central government of the Czech Republic. The ISBN: 978-960-474-335-3 241 Recent Advances in Geodesy and Geomatics Engineering CZSO also hold the data concerning the health and 2.3 Scale of the Data medical problematic, which are located in the public The aim of clinical studies is to explore the relations database within several topics (demography, health on the individual level. Every single patient is taken service, etc.). into account as one unit, while several persons are The third provider is the National Institute of considered as data set. The data confidentiality is Public Health (http://www.szu.cz/), which is a also the difference in the geoscience. The possibility health care establishment for basic preventive of analyzing