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The openEHR specifications are designed to support implementation of flexible and interoperable Electronic Health Record (EHR) systems. Despite the increasing number of solutions based on the openEHR specifications, it is difficult to find publicly available healthcare datasets in the openEHR format that can be used to test, compare and validate different data persistence mechanisms for openEHR. To foster research on openEHR servers, we present the openEHR Benchmark Dataset, ORBDA, a very large healthcare benchmark dataset encoded using the openEHR formalism. To construct ORBDA, we extracted and cleaned a de-identified dataset from the Brazilian National Healthcare System (SUS) containing hospitalisation and high complexity procedures information and formalised it using a set of openEHR archetypes and templates. Then, we implemented a tool to enrich the raw relational data and convert it into the openEHR model using the openEHR Java reference model library. The ORBDA dataset is available in composition, versioned composition and EHR openEHR representations in XML and JSON formats. In total, the dataset contains more than 150 million composition records. We describe the dataset and provide means to access it. Additionally, we demonstrate the usage of ORBDA for evaluating inserting throughput and query latency performances of some NoSQL database management systems. We believe that ORBDA is a valuable asset for assessing storage models for openEHR-based information systems during the software engineering process. It may also be a suitable component in future standardised benchmarking of available openEHR storage platforms., Funding Agencies|CNPq [150916/2013-2]; INCT-MACC [15/2008]

Archetype-based Electronic Health Record (EHR) systems using generic reference models from e.g. openEHR, ISO 13606 or CIMI should be easy to update and reconfigure with new types (or versions) of data models or entries, ideally with very limited programming or manual database tweaking. Exploratory research (e.g. epidemiology) leading to ad-hoc querying on a population-wide scale can be a challenge in such environments. This publication describes implementation and test of an archetype-aware Dewey encoding optimization that can be used to produce such systems in environments supporting relational operations, e.g. RDBMs and distributed map-reduce frameworks like Hadoop. Initial testing was done using a nine-node 2.2 GHz quad-core Hadoop cluster querying a dataset consisting of targeted extracts from 4+ million real patient EHRs, query results with sub-minute response time were obtained.

This study provides an experimental performance evaluation on population-based queries of NoSQL databases storing archetype-based Electronic Health Record (EHR) data. There are few published studies regarding the performance of persistence mechanisms for systems that use multilevel modelling approaches, especially when the focus is on population-based queries. A healthcare dataset with 4.2 million records stored in a relational database (MySQL) was used to generate XML and JSON documents based on the openEHR reference model. Six datasets with different sizes were created from these documents and imported into three single machine XML databases (BaseX, eXistdb and Berkeley DB XML) and into a distributed NoSQL database system based on the MapReduce approach, Couchbase, deployed in different cluster configurations of 1, 2, 4, 8 and 12 machines. Population-based queries were submitted to those databases and to the original relational database. Database size and query response times are presented. The XML databases were considerably slower and required much more space than Couchbase. Overall, Couchbase had better response times than MySQL, especially for larger datasets. However, Couchbase requires indexing for each differently formulated query and the indexing time increases with the size of the datasets. The performances of the clusters with 2, 4, 8 and 12 nodes were not better than the single node cluster in relation to the query response time, but the indexing time was reduced proportionally to the number of nodes. The tested XML databases had acceptable performance for openEHR-based data in some querying use cases and small datasets, but were generally much slower than Couchbase. Couchbase also outperformed the response times of the relational database, but required more disk space and had a much longer indexing time. Systems like Couchbase are thus interesting research targets for scalable storage and querying of archetype-based EHR data when population-based use c, Funding agencies: Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES Foundation - Brazil) [4055/11]; Conselho Brasileiro de Desenvolvimento Cientifico e Tecnologico (CNPq) [150916/2013-2]

There are very few published studies regarding the performance of persistence mechanisms for systems that use the openEHR multi level modelling approach. This paper addresses the performance and size of XML databases that store openEHR compliant documents. Database size and response times to epidemiological queries are described. An anonymized relational epidemiology database and associated epidemiological queries were used to generate openEHR XML documents that were stored and queried in four opensource XML databases. The XML databases were considerably slower and required much more space than the relational database. For population-wide epidemiological queries the response times scaled in order of magnitude at the same rate as the number of records (total database size) but were orders of magnitude slower than the original relational database. For individual focused clinical queries where patient ID was specified the response times were acceptable. This study suggests that the tested XML database configurations without further optimizations are not suitable as persistence mechanisms for openEHR-based systems in production if population-wide ad hoc querying is needed.

In recent years we have observed an incredible increase in location-specific information provided voluntarily by individuals and disseminated via the internet. The emergence of this Volunteered Geographic Information (VGI) as Goodchild first described it in 2007 has attracted considerable interest within the GIScience research community. As a special type of user generated content, it offers great potential to produce up-to-date and near real-time information related to any place on Earth, even though overall accuracy remains an issue of debate. Location sharing services (LSS) such as ‘foursquare’, ‘Gowalla’, and ‘Facebook Places’ collect hundreds of millions of user-driven footprints or ‘check-ins’. Those footprints provide a unique opportunity to study social and temporal characteristics of how people use these services and model patterns of human mobility. However, the amount and frequency of VGI is not evenly distributed and recent research considers it directly related to socioeconomic characteristics of its contributors (i.e.,geographic and economic constraints, individual social status) . Particularly in the context of population dynamics studies, VGI may provide a data source that is more accessible and current as well as less expensive and timeconsuming than traditional activity survey data. VGI generated on micro-blogging services and location-based social networks (LBSN) bear the greatest resemblance to the activity diary that time geographers are familiar with . Noulas et al. present a large-scale study of user behavior on the LBSN platform ‘foursquare’, analyzing user check-in dynamics and demonstrating how that reveals meaningful spatio-temporal patterns and offers the opportunity to study both user mobility and characteristics of urban spaces. In this study we compare functionally categorized location-specific foursquare check-in information picturing one working week in the Lisbon Metropolitan Area to a daytime working population surface produced in, Peer Reviewed