Background: As a common psychological problem in cancer patients, illness uncertainty has attracted wide attention from scholars. Some studies have pointed out that the level of social support may affect illness uncertainty in patients with cancer, but the results of these studies remain controversial. Objective: The aim of this study was to evaluate the correlation between illness uncertainty and social support in patients with cancer using meta-analysis. Methods: PubMed, Web of Science, EMBASE, EBSCO, Cochrane Library, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, and VIP Citation Database were searched for articles published up to 2022. The screening of the literature, data extraction, and quality assessment of the included studies were performed independently by 2 researchers. Stata 17.0 software was used to analyze the overall and moderation effects. Results: Notably, 41 studies involving 5403 patients were included. The results showed that the illness uncertainty of adults with cancer was moderately negatively correlated with social support ( r = −0.33). Country, publication year, cancer type, and instrument used to measure social support moderated the association between illness uncertainty and social support. Conclusion: Improving the level of social support can reduce illness uncertainty experienced by adults with cancer to a certain extent. Implications for Practice: This review provides a clear direction for implementing precise interventions to reduce illness uncertainty among adults with cancer. Furthermore, patients with cancer with high morbidity and mortality rates deserve greater attention from healthcare personnel and family caregivers.

Little is known about the psychosocial pathways linking social support to health-related quality of life (HRQoL) in family caregivers of people with dementia (PwD). This study aimed to explore how self-efficacy and caregiver distress mediate the relationship between social support and caregivers' HRQoL. This study utilized baseline data from a randomized controlled trial involving 266 Chinese dementia caregivers recruited from China and Australia. Four self-report scales were used: the Chinese version of the Carers of Older People in Europe Index-Quality of Social Support, the Revised Scale for Caregiving Self-efficacy, the Revised Memory and Behavior Problem Checklist and the 12-Item Short-Form Health Survey. Structural equation modeling was conducted using AMOS 26.0 to examine the mediating roles of self-efficacy and caregiver distress in mediating the relationship between social support and HRQoL. Social support was significantly associated with HRQoL. It also indirectly predicted physical HRQoL through caregiving self-efficacy (β = 0.062) and caregiver distress (β = 0.070), accounting for 38.88 % of the total effect. Besides, social support indirectly predicted mental HRQoL through self-efficacy (β = 0.182) and caregiver distress (β = 0.041), contributing to 58.1 % of the total effect. Self-efficacy and caregiver distress functioned as sequential mediators in this association. Social support was positively associated with HRQoL, both directly and indirectly, through the serial mediating role of self-efficacy and caregiver distress among family caregivers of PwD. Our findings highlight the importance of providing psychosocial interventions to improve HRQoLfor dementia caregivers.