Common Dimensions
Common dimensions (sometimes referred to as 'conformed dimensions') are an essential component of data warehousing.
Common dimensions
In a 'dimensional' data warehouse such as the NHSScotland Corporate Data Warehouse (CDW), data in each data mart are partitioned into 'facts' or 'dimensions'. Facts are normally numeric information whereas dimensions are the reference information that gives context to the 'facts' (e.g. organisation, time, patient, individual, drug). The use of dimensions common to all data marts provides consistent coding and descriptions across marts, but more importantly allows users to seamlessly analyse data across multiple marts. Within the CDW history of dimensions is retained as well as history of fact data, which supports complex longitudinal analysis e.g. for epidemiological and outcomes studies.
NHSScotland Corporate Data Warehouse Common Dimensions
NHS National Services Scotland IM&T hold the common dimensions used within the NHSScotland Corporate Data Warehouse (CDW). These provide consistency across data marts to describe a range of data relating to and including patients, location and organisation. By incorporating common dimensions into developments enables data across a range of data marts to be joined across organisational boundaries within the NHSScotland CDW.
