Social support and health-related quality of life among the oldest old — longitudinal evidence from the multicenter prospective AgeCoDe-AgeQualiDe study

PURPOSE: The aim of this study was to examine the longitudinal within-association between social support and health-related quality of life among the oldest old. METHODS: Longitudinal data (follow-up waves 7 to 9) were used from the multicenter prospective cohort study “Needs, health service use, costs and health-related quality of life in a large sample of oldest-old primary care patients (85 +)” (AgeQualiDe). n = 648 individuals were included in the analytical sample. At FU wave 7, mean age was 88.8 years (SD: 2.9 years, from 85 to 99 years). Social support was quantified using the Lubben Social Network Scale (6-item version). Health-related quality of life was assessed using the EQ-5D-3L including problems in five health dimensions, and its visual analogue scale (EQ VAS). It was adjusted for several covariates in conditional logistic and linear fixed effects regressions. RESULTS: Intraindividual decreases in social support were associated with an increased likelihood of developing problems in ‘self-care’, ‘usual activities’, ‘pain/discomfort’ and ‘anxiety/depression’ (within individuals over time). In contrast, intraindividual changes in social support were not associated with intraindividual changes in the EQ VAS score. CONCLUSION: Findings indicate a longitudinal intraindividual association between social support and problems, but only in some health dimensions. Further research in this area based on longitudinal studies among the oldest old (from different countries) is required. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11136-021-03070-2.