Using SPSS 27, (Statistical Package for Social Science, IBM) an explorative principal axis factor analysis with varimax rotation was performed to identify aggregated domains of cognitive functioning (see Supplement). As neuropsychological test variables were differentially scaled, z-transformed values were used for the factor analysis. Suitability of neuropsychological test data for factor analysis was tested using Bartlett’s test of sphericity [55] and the Kaiser–Meyer–Olkin test (KMO) [56]. Factors were extracted according to the Kaiser’s eigenvalue greater than one criterion [57]. Factor loadings were extracted using the regression method as implemented in SPSS.
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