The UKB data fields corresponding to each variable are outlined in Table S5 in supporting information. Covariates were obtained from the imaging assessment and missing values were backfilled with baseline survey responses (Table S6 in supporting information). The multiple imputation by chained equations (MICE) method with the classification and regression trees (CART) approach was then used to impute any remaining missing values. 26 Detailed explanations of variable processing and handling of missing data can be found in Text S1.
