Patterns of hospital-associated complications reflecting multidimensional vulnerability and their prognostic significance in hospitalized older adults.

Hospital-associated complications (HACs), including delirium, falls, pressure ulcers, urinary incontinence, and functional decline, frequently co-occur in hospitalized older adults. However, these complications have typically been studied as isolated events. This study aimed to identify latent phenotypes of HACs and examine their associations with admission geriatric characteristics and short-term mortality. In this multicenter observational cohort study, 1599 older adults admitted to acute care hospitals were included. HACs during hospitalization were assessed, and latent class analysis was used to identify phenotypes. Associations with admission-level frailty, functional status, cognitive function, and nutritional status were examined. Discriminative performance was evaluated using receiver operating characteristic analysis, and three-month mortality after discharge was assessed. A three-class latent structure was identified, although separation between the two lower-risk classes was limited. One subgroup, comprising 19% of participants, was characterized by high probabilities of multiple co-occurring complications, particularly functional decline and delirium, and was designated the global HAC phenotype. Admission frailty, functional impairment, and cognitive dysfunction were significantly associated with this phenotype (area under the curve = 0.755). Three-month mortality was significantly higher in the global HAC phenotype compared with other phenotypes (22.2%vs 5.2%), and this association remained significant after multivariable adjustment (adjusted odds ratio 2.24, 95% confidence interval 1.25-4.03). HACs cluster into clinically meaningful phenotypes reflecting multidimensional vulnerability. A global HAC phenotype can be identified from admission assessments and is associated with increased short-term mortality, supporting phenotype-based risk stratification in hospitalized older adults.