Intrinsic capacity and mortality in community-dwelling octogenarians: a network analysis from the ilSIRENTE study

Intrinsic capacity (IC) is a key construct within the healthy ageing framework. However, the correlations among IC domains and their association with health outcomes in very old adults remain unclear. This study aimed to characterise the relationships among IC domains using network analysis and to examine their association with mortality in community-dwelling octogenarians from the Invecchiamento e Longevità nel Sirente (ilSIRENTE) cohort. IC was calculated as a summary score rescaled to a 0-100 range across locomotion, cognition, vitality, psychological capacity, and sensory function, derived from routine home-based geriatric assessments (Minimum Data Set for Home Care instruments and supplementary tests). Assessments were conducted at designated centres, with home visits arranged for individuals unable to travel. The final sample included 319 community-dwelling adults aged ≥ 80 years (mean age 85.4 ± 4.8 years; 67.1% women). Network analysis suggested clustered relationships among vitality, psychological, and cognitive domains, whereas sensory domains appeared more peripheral. Hearing and vision were associated with locomotion, while their association with cognition appeared to be mediated by locomotion. In Cox proportional hazards models, higher locomotion scores were independently associated with lower mortality at 4 years [hazard ratio (HR) 0.86, 95% CI 0.80-0.93] and 7 years (HR 0.87, 95% CI 0.81-0.92). Each 10-point increase in IC was associated with lower mortality at 4 years (HR 0.67, 95% CI 0.58-0.77) and 7 years (HR 0.68, 95% CI 0.61-0.77). Among very old adults, locomotion emerged as a central functional domain linking sensory function, cognition, and survival within the IC framework. IC measures derived from routine assessments may provide a pragmatic approach for risk stratification and targeted interventions to promote healthy ageing.