As mentioned above, because LTAA were older than TxN, we recruited two different (age and gender comparable) control groups (see Table 1). Before comparing LTAA to TxN, we examined for cohort effects by comparing their respective control groups on the SSS. There was no multivariate difference between the control samples on the SSS (Wilkes λ4,111 = 0.989, p = 0.417), nor were there differences on any SSS subscale (all p’s > 0.17, all effects sizes < 1.6% of the variance), indicating that the control groups could be combined in further analyses. The lack of cohort effects also supports the direct comparison of the LTAA and TxN samples. These results suggest that total SSS scores in NAC did not change with age, which was confirmed by correlation analysis (Spearman’s rho comparing total SSS score with age: entire NAC sample = 0.11, p = 0.23; NAC for TxN study = −0.13, p = 0.27, NAC for LTAA study = 0.00, p = 0.98).
