Fig. 3
Interaction Between Cognitive Reserve and Predicted Age Difference (PAD) on Total Disease Duration. The figure illustrates the relationship between CR and total disease duration, stratified by brain age group. Patients were categorized as having a “Younger Brain” (green line; PAD < 0) or “Older Brain” (orange line; PAD > 0), based on whether their predicted brain age was younger or older than their chronological age, respectively. The plotted regression lines indicate that higher CR is associated with longer total disease duration in both groups. However, the slopes remain nearly parallel, suggesting that the association between R and disease duration is not significantly moderated by PAD. Shaded areas represent 95% credible intervals, which overlap substantially between groups, further supporting the absence of a meaningful interaction effect. Notably, the y-axis intercepts indicate that, at the lowest observed levels of CR, patients with an older brain tend to have a shorter predicted disease duration than those with a younger brain. These findings indicate that while both CR and PAD may influence disease duration, their effects appear to be largely independent.
