Dyadic Coping and Illness Uncertainty in Cancer Patient-Caregiver Dyads: Interactive Mechanisms, Heterogeneity, and Integrated Intervention Directions-A Narrative Review (2021-2025).

Cancer patient-informal caregiver dyads function as core collaborative units across the cancer trajectory from diagnosis to recovery. A central challenge for these dyads lies in managing illness uncertainty alongside the demands of dyadic coping, two interrelated factors that jointly shape long-term quality of life, psychological well-being, and disease adaptation. These two factors interact to shape their long-term quality of life, psychological well-being, and disease adaptation. Past studies have mostly examined dyadic coping and illness uncertainty separately. Employing a narrative review design, this study searched the PubMed database for literature published from 2021 to 2025, and synthesizes evidence on association pathways and moderating factors between dyadic coping and illness uncertainty among adult cancer patient-informal caregiver dyads. Existing research on dyadic coping has predominantly focused on the effects of interventions (e.g., enhanced spousal communication, joint exercise) on emotional health and relationship quality. Studies on illness uncertainty have largely examined its association with anxiety and depression, but have failed to provide a comprehensive understanding of the interactive pathways between the two constructs. This review addresses this gap by synthesizing evidence from three perspectives: interactive mechanisms, heterogeneous characteristics, and integrated intervention directions. Evidence from the reviewed literature suggests that illness uncertainty represents a critical antecedent of dyadic coping among cancer dyads. Illness uncertainty and dyadic coping share a bidirectional association, and this relationship is moderated by factors including cancer type, patient age, and cultural background. Most uncertainty management interventions effectively reduce illness uncertainty in specific populations. Synthesized evidence indicates that dyadic coping is a significant predictor of relationship satisfaction among couples coping with chronic illness. Interventions that are made for these couples need to include things like psychoeducation and skill-building parts that are about dyadic coping, so that they can improve the couples' relationship satisfaction. Based on predominantly observational evidence with heterogeneous study designs, the authors propose that combining uncertainty management interventions with dyadic coping skills training represents a key direction for future clinical care optimization. This review provides evidence-based implications for developing targeted dyadic care strategies and advancing family-centered, full-course cancer care models.