Egenvall et al. Acta Veterinaria Scandinavica 2011, 53(Suppl 1):S4 http://www.actavetscand.com/content/53/S1/S4 P R O C E E D I N G S Open Access Integrating databases for research on health and performance in small animals and horses in the Nordic countries Agneta Egenvall1*, Ane Nødtvedt2, Lars Roepstorff3, Brenda Bonnett1 From Databases in veterinary medicine: validation, harmonisation and application. The 24th Symposium of the Nordic Committee for Veterinary Scientific Cooperation (NKVet) Copenhagen, Denmark. 19-20 April 2010 Abstract In a world of limited resources, using existing databases in research is a potentially cost-effective way to increase knowledge, given that correct and meaningful results are gained. Nordic examples of the use of secondary small animal and equine databases include studies based on data from tumour registries, breeding registries, young horse quality contest results, competition data, insurance databases, clinic data, prescription data and hunting ability tests. In spite of this extensive use of secondary databases, integration between databases is less common. The aim of this presentation is to briefly review key papers that exemplify different ways of utilizing data from multiple sources, to highlight the benefits and limitations of the approaches, to discuss key issues/challenges that must be addressed when integrating data and to suggest future directions. Data from pedigree databases have been individually merged with competition data and young horse quality contest data, and true integration has also been done with canine insurance data and with equine clinical data. Data have also been merged on postal code level; i.e. insurance data were merged to a digitized map of Sweden and additional meteorological information added. In addition to all the data quality and validity issues inherent in the use of a single database, additional obstacles arise when combining information from several databases. Loss of individuals due to incorrect or mismatched identifying information can be considerable. If there are any possible biases affecting whether or not individuals can be properly linked, misinformation may result in a further reduction in power. Issues of confidentiality may be more difficult to address across multiple databases. For example, human identity information must be protected, but may be required to ensure valid merging of data. There is a great potential to better address complex issues of health and disease in companion animals and horses by integrating information across existing databases. The challenges outlined in this article should not preclude the ongoing pursuit of this approach. Introduction Why databases? In a world of limited resources, using existing databases in research is a potentially cost-effective way to increase knowledge, given that correct and meaningful results are gained. The databases can provide a better understand- ing of issues at the population level, without costly and * Correspondence: agneta.egenvall@slu.se 1The Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden Full list of author information is available at the end of the article time-consuming primary research. Because research based on databases is generally retrospective in nature, it might be reasonable to re-evaluate the results using prospective designs at a later stage. Both primary and secondary databases, i.e. those constructed specifically for a research purpose or not, respectively, might be used depending on the research question [1]. What con- stitutes a secondary database can sometimes be hard to judge. For example, in this article pedigree databases will be considered secondary, although their primary purposes may be not only to have control over the pedi- gree of each animal, but also to analyse hereditary © 2011 Egenvall et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.