Background Older adults admitted to intensive care units (ICUs) following elective surgery face heterogeneous trajectories of recovery spanning the physical, cognitive and social domains. Biological ageing processes, including cellular senescence, may modulate these outcomes. Here, we present the protocol for an analytic prospective observational cohort study integrating biopsychosocial assessments and senescence-associated biomarkers to identify predictors of health-related quality of life (HRQoL) and post-ICU recovery. Methods and analysis Single-centre, prospective cohort study at the University Hospital Halle (Saale), Germany. Adults aged 60 years or older scheduled to undergo elective surgery and who have a planned postoperative stay in the ICU of at least 24 hours and who are able to provide consent will be enrolled. Baseline pre-ICU data will include the following: medical history, comorbidity, medications, routine laboratory values and a comprehensive geriatric assessment (eg, frailty, mobility, handgrip strength, Timed Up & Go, cognition, mood, loneliness, social status and EuroQol 5-Dimension 5-Level, EQ-5D-5L). A 5 mL serum sample will be collected for a senescence-associated secretory phenotype panel and additional ageing biomarkers. Skin autofluorescence will be used to estimate advanced glycation end-products. Telephone follow-ups at 3 and 6 months ascertain HRQoL, functional outcomes, psychosocial outcomes, rehospitalisations and institutionalisation. The primary endpoint is defined as a stable or improved HRQoL (EQ-5D-5L) at 3/6 months vs baseline. We intend to use multivariable predictive modelling with elastic-net regularisation and conduct internal validation using bootstrap resampling and cross-validation. Ethics and dissemination This study has been approved by the Ethics Committee of the Medical Faculty, Martin-Luther-University Halle-Wittenberg (No. 2025-112). Written informed consent is obtained from all participants. The results of this study will be reported in a peer-reviewed journal. Trial registration number DRKS00037969.
Schümann et al. (Wed,) studied this question.