This will permit an assessment of replicability of white matter hyperintensities (WMH) measurements across studies, and an analysis of the relationship of WMH to demographic and cognitive variables. The harmonised WMH measures will be delivered back on the DPUK Data Portal, and the harmonisation tools will be made available as a DPUK app. This will produce novel multi-study analyses that combine the individual strengths of DPUK datasets, greatly enhancing our ability to understand the role of WMH in cognitive ageing.