Do concordances of social support and relationship quality predict psychological distress and well-being of cancer patients and caregivers?

This study examined concordances of cancer patients' received and caregivers' provided support and dyadic relationship quality, and their predictive utility in prospective psychological distress and well-being. A total of 83 Chinese cancer patient-caregiver dyads were recruited in two government-funded hospitals in Hong Kong. Participants reported received (patient)/provided (caregiver) emotional and instrumental support and dyadic relationship quality within 6 months after diagnosis (T1), and anxiety and depressive symptoms, positive affect and life satisfaction at both T1 and 6-month follow-up (T2). We hypothesised that concordances at T1 would predict lower psychological distress and higher psychological well-being among both patients and caregivers at T2. Concordances were indicated by Gwet's AC2 scores (possible range = -1.00 to 1.00) and as follows: emotional support: M = 0.92, SD = 0.12, range = 0.25-1.00; instrumental support: M = 0.92, SD = 0.16, range = 0.08-1.00; and relationship quality: M = 0.63, SD = 0.27, range = -0.31 to 1.00. Hierarchical multiple regressions revealed that T1 concordances of perceived emotional and instrumental support and dyadic relationship quality positively predicted T2 anxiety symptoms [F(9, 74) = 6.725, ∆R2  = .031, p < .001)] and state positive affect [F(9, 74) = 3.436, ∆R2  = .042, p = .001)], whereas inversely predicted T2 depressive symptoms [F(9, 74) = 4.189, ∆R2  = .042, p < .01)]. Significant associations were found only among caregivers, but not patients.