Physical Performance and Mental Health in Institutionalized Older Adults: A Multicenter, Cross-Sectional Observational Study

Aging and institutionalization, associated with functional and psychological decline, justify studying how physical performance is linked to mental health in older adults. <b>Objectives</b>: To analyze the relationship between physical performance and anxiety, depression, sleep quality, and perceived stress in institutionalized older adults. <b>Methods</b>: Multicenter, observational, cross-sectional study in eight nursing homes (<i>N</i> = 105; ≥65 years, M = 80.78 SD ± 7.91). Instruments: SPPB, HADS, PSQI, PSS-10. Descriptives and exploratory bivariate tests. Primary analysis: single multivariable linear regression with SPPB as outcome and HADS-A, HADS-D, PSQI, PSS-10 entered simultaneously, adjusted for age and sex. Robustness: GLM with robust SEs, influence sensitivity excluding Cook's D > 4/n or leverage > 2 p/n, and a proportional-odds model for SPPB. All statistical tests were two-sided, with α set at 0.05. <b>Results</b>: Mean SPPB was 6.94 ± 3.17; 77.1% of participants showed poor physical performance. Bivariate: All mental health constructs showed significant associations with physical performance. Multivariable model: adjusted <i>R</i>² = 0.198; <i>F</i> (6,98) = 5.28, <i>p</i> < 0.001. Depression <i>B</i> = -0.230 (95% CI -0.398 to -0.061), <i>p</i> = 0.008; sleep quality (higher = worse) <i>B</i> = -0.187 (95% CI -0.351 to -0.024), <i>p</i> = 0.025; age <i>B</i> = -0.087 (95% CI -0.158 to -0.017), <i>p</i> = 0.016. Anxiety showed a positive adjusted association <i>B</i> = +0.224 (95% CI 0.038 to 0.410), <i>p</i> = 0.019 (consistent with suppression); perceived stress <i>B</i> = -0.062, <i>p</i> = 0.275; sex <i>B</i> = -0.144, <i>p</i> = 0.812. Robust SEs left inferences unchanged. Influence sensitivity (<i>n</i> = 97) preserved directions with the PSQI association attenuating to non-significance. Ordinal results were directionally consistent. <b>Conclusions</b>: After adjusting for age and sex, depression and sleep quality independently relate to physical function, while age is inversely associated; anxiety and perceived stress show no independent effects.