The phase model of aging as a basis for reorganizing geriatric care: from chronological age to functional stratification.

<jats:p>Introduction. Demographic aging and the rise of multimorbidity necessitate a revision of the linear approach to geriatric care based on chronological age. The COVID‑19 pandemic has created a new cohort of patients with resistant post-infection asthenia (PIA/Long COVID), highlighting the need for differentiated patient routing and age-stratified screening thresholds. Objective: to develop patient routing algorithms for geriatric patients based on the phase model of aging. Materials and methods. A retrospective analysis of 504 patients (aged 60–90+ years) was conducted using regression analysis. Results and discussion. Three phases of aging were identified: 60–74, 75–89, and 90+ years. In the 75–89 age phase, age is not a predictor of functional status (R² = 0.14–0.27). Evidence-based thresholds were established: screening at age 70, referral to a geriatrician at age 75. Conclusion. The phase model of aging represents a scientifically grounded alternative to the linear paradigm. Its implementation improves the efficiency of human resource utilization, reduces economic losses from unnecessary screening, and enhances the quality of geriatric care.</jats:p>