Factors associated with sustained robustness in older adults: an 8-year multinational longitudinal study using SHARE...

Frailty is a widely recognized clinical syndrome of ageing. While most studies emphasize risk factors for frailty, less is known about the factors associated with sustained robustness in later life. This study addresses this gap by examining baseline characteristics associated with the subsequent maintenance of robustness among older adults.

We analyzed eight years of longitudinal data from the Survey of Health, Ageing and Retirement in Europe (SHARE; Waves 4-8, 2011-2020) across 27 countries, including 7,865 adults aged 65-84 who were robust at baseline and had frailty information available in at least one follow-up wave; participants were stratified into younger-old (65-74) and older-old (75-84) groups. Logistic regression models estimated odds ratios for maintaining robustness, incorporating sociodemographic, health, lifestyle, and functional factors.

Robustness declined steadily over time, with 52% of younger-old adults and 26% of older-old adults remaining robust after eight years. Across all models, better self-rated health (OR ≈ 0.72, p < 0.001), fewer chronic conditions (OR ≈ 0.89, p < 0.001), and greater financial security (OR ≈ 1.11, p = 0.018) were the strongest and most consistent predictors of sustained robustness. Participation in social and cognitive activities was also associated with sustained robustness in some models. Baseline physical activity showed positive associations in the primary analyses, although these findings require cautious interpretation because physical activity also contributed to the operational definition of robustness.

This study contributes to ageing research by examining sustained robustness, rather than frailty progression alone, as a longitudinal outcome in a large multinational cohort. By identifying behavioral, psychosocial, and functional characteristics associated with sustained robustness, the study frames robustness as a measurable longitudinal outcome in ageing research and practice. These findings support a more balanced and positive conceptualization of ageing - one that emphasizes not only preventing frailty, but also maintaining robustness as an important scientific and clinical objective.