VIVA Project: Multidimensional Vulnerability Profiles in Institutionalized Older Adults During the Late COVID-19 Period

Background/Objectives: The health status of institutionalized older adults is determined by the interaction of functional, cognitive, nutritional, anthropometric, and biochemical factors, which may not be adequately captured through single-domain assessments. Within the framework of the VIVA Project (Vulnerability Index: Valencia institutionalized Adults), this study aimed to characterize institutionalized older adults during the COVID-19 pandemic using an integrated multidimensional approach and to explore clinically interpretable vulnerability profiles. Methods: This cross-sectional study included 124 residents from 10 nursing homes of Valencia, Spain. Data were obtained from institutional records and included age, sex, body mass index (BMI), Barthel Index, Mini-Examination of Cognition (MEC), Tinetti scale, Mini Nutritional Assessment-Short Form (MNA-SF), and biochemical markers related to protein status, lipid metabolism, micronutrient availability, and renal function. An exploratory VIVA multidimensional index was constructed from nine standardized variables, and k-means clustering was applied to these variables rather than to a single summed score to identify residents’ phenotypes. An exploratory logistic regression model was used to assess the internal discrimination of the high-vulnerability phenotype. Results: The cohort showed marked heterogeneity across functional, cognitive, nutritional, anthropometric, and biochemical domains. Cluster analysis identified three clinically interpretable phenotypes ranging from lower to higher vulnerability. Functional impairment, particularly the Barthel Index and Tinetti score, was the main driver of separation between phenotypes, while biochemical markers contributed to refining profile discrimination. The exploratory logistic regression model showed high internal discrimination for the high-vulnerability phenotype, supporting the internal coherence of the integrated framework. Conclusions: An integrated multidimensional framework may be useful for characterizing vulnerability among institutionalized older adults and supporting risk stratification in long-term care settings. The logistic regression findings, including the high AUC, should be interpreted only as evidence of internal discrimination and internal coherence of the exploratory construct, not as evidence of external validity, reproducibility, diagnostic accuracy, or future predictive utility.