Principal components were retained if
their eigenvalues were greater than 1.0, a threshold that is commonly
used as a cut-off to identify meaningful patterns. The resulting components
were interpreted based on the variables with loadings above
0.3.Moreover, the Kaiser–Meyer–Olkin criterionwas used as a measure
of variable (component) inter-correlation and used as an indicator of internal
consistency, which is an important attribute of an index that intends
to measure a single underlying concept (in this case successful
aging).