Fig. 1. Distribution of the cognitive domains across all waves of data collection for the 6817 ELSA participants included in this study presented as means and standard deviations.

The baseline data were obtained from either wave 2 (2004–2005) for the core members who started at wave 1, or wave 4 for the participants joining the study at wave 4 through the refreshment sample. Follow-up data were ascertained from waves 4 (2009–2010) to wave 8 (2016–2017), which is the latest wave of data collection.