Dimensions of Self-Perceived Functionality in Older Adults Based on the Brazilian National Health Survey.

The aging population is a global phenomenon that represents a significant demographic shift, with life expectancy closely related to individuals' functional capacity. BACKGROUND/OBJECTIVES: Identify latent dimensions in self-perceived functional variables among Brazilian older adults. METHODS: This cross-sectional study used data from module K of the 2019 National Health Survey (NHS) in Brazil. Multivariate statistics were applied using Principal Component Analysis (PCA). RESULTS: The sample consisted of 22,728 older adults from all regions of Brazil, with a predominance of females (56%), an average age of 70 years (CI: 69.68-70.03), 61% engaged in weekly physical exercise, and most living with a spouse or partner (56.3%). The multivariate statistical analysis, conducted through PCA, resulted in two distinct macro-dimensions of functionality: Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs). When analyzing each macro-dimension separately, we identified internal micro-dimensions. Within ADLs, two subdimensions stood out: ADLs Upper Limb Function and ADLs Lower Limb Function. Within IADLs, the micro-dimensions included IADLs Health Management and IADLs Independent Outdoor Mobility. Close results in the subdimensions of variable K25 did not allow for a clear distinction between the estimated IADLs. However, given the importance of this variable in explaining the cognitive aspect of the functional capacity construct, we suggest maintaining it as a separate subdimension: IADLs Financial Management. CONCLUSIONS: The latent dimensions of functional capacity identified in this study may help guide functional assessment in older adults, inform therapeutic decision-making, shape public policy, and support further research on functional capacity in aging populations.