Opportunities for longitudinal data linkage in Scotland.

Scotland has existing data resources which are competitive internationally and available to researchers from elsewhere. The Scottish Informatics and Linkage Collaboration (SILC) was recently launched, allowing data sets to be linked within and between sectors (e.g. health to non-health). The purpose of this review article is to introduce and define key terms in data linkage, to describe the emerging data linkage resources available in Scotland and to describe the opportunities available in Scotland to researchers internationally. The review is aimed at researchers internationally who are interested in data linkage using Scottish data resources. The review makes particular reference to longitudinal health data but emphasises that linkage to non-health data allows research questions to be considered that were previously not answerable. The review is focused on longitudinal data resources (e.g. cohort studies and repeated measures designs), since they are usually the focus of data linkage research. The review concludes that any intended data linkage for research should be driven by a clear research question. The infrastructure already available and the launch of SILC will accelerate research in Scotland and generate new research questions that previously could not be considered.