Illness Perception Mediation and Disease Characteristics Moderation of the Relationship Between Health Literacy and Self-Care Behaviors in Chronic Kidney Disease.

BACKGROUND

Health literacy (HL) is widely recognized as a determinant of self-care behaviors in chronic kidney disease (CKD). Grounded in the Common-Sense Model of Self-Regulation, illness perception may serve as a cognitive intermediary in this relationship, yet which specific dimensions carry this role in CKD remains unclear.

OBJECTIVE

This study examined the mediating roles of illness perception dimensions in the relationship between CKD-specific HL and self-care behaviors and explored how demographic and disease characteristics moderated this pathway.

METHODS

We conducted a cross-sectional study among 235 adults with CKD stage 3 or higher, recruited from the nephrology outpatient department of a regional hospital in central Taiwan. Participants completed validated measures of CKD-specific HL, illness perception across seven dimensions, and self-care behaviors. We performed mediation and moderated mediation analyses with 5,000 bootstrap samples.

RESULTS

HL was linked to three of the seven illness perception dimensions, namely timeline acute/chronic, personal control, and treatment control, while four dimensions-timeline cyclical, personal control, treatment control, and illness coherence-were related to self-care behaviors. Treatment control was the only dimension that mediated the relationship between HL and self-care behaviors; the other three dimensions did not. CKD duration moderated this mediating pathway. The indirect association between HL and self-care behaviors through treatment control was present among patients with shorter CKD duration but weakened and became non-significant as CKD duration increased.

DISCUSSION: Treatment control may be an important cognitive pathway linking HL to self-care in CKD. This pathway appeared more evident among patients with shorter disease duration, suggesting that HL-based support may be particularly useful when patients are still developing their understanding of CKD and confidence in treatment. For patients with a longer illness history, self-care support may need to move beyond information provision and address treatment confidence and the challenges of long-term disease management.