Abstract
BACKGROUND: Reported estimates of frailty prevalence vary considerably. At least partially attributable to differences in the conceptualization of frailty used, a better understanding of the inter-relationships among frailty domains could clarify contributors to the noted heterogeneity. METHODS: A global frailty index (FI) created from baseline data on 30,097 Canadian Longitudinal Study on Aging comprehensive cohort participants was used to define physical, psychological, cognitive, and social domain-specific FIs. These were divided into quintiles with the highest 20% (Q5) representing the frailest participants. Logistic regression was used to estimate the associations between age group and biological sex with domain-specific FIs in unadjusted and adjusted (income, smoking status, nutritional risk, physical activity, social participation, interaction between sex and age group) models. The association between Q5 membership among the frailty domains was estimated using polychoric correlation coefficients. RESULTS: The prevalence of physical and cognitive frailty increased with age, but psychological frailty decreased, especially in males. Social frailty showed gradual increases with age in females that were only evident in the oldest age group (75-85) among men. The age-groups*sex interaction p value was p<.001 for social. Polychoric correlations were highest between the psychological/physical and psychological/social domains, and decreased with increasing age for all combinations. CONCLUSION: We found that domain-specific frailty prevalences differed by age group and sex with low associations among frailty domains, particularly at older ages. Understanding the evolution of these findings could be instrumental in developing tailored interventions to prevent frailty or modify its trajectory.