Frailty Assessment in Vascular OUtpatients Review (FAVOUR) protocol: single-centre prospective cohort study comparing feasibility and prognostic value of commonly used frailty assessment tools.

INTRODUCTION: Frailty has consistently demonstrated associations with poorer healthcare outcomes. Vascular guidelines have recognised the importance of frailty assessment. However, an abundance of frailty tools and a lack of prospective studies confirming suitability of routine frailty assessment in clinical practice has delayed the uptake of these guidelines. The Frailty Assessment in Vascular OUtpatients Review study speaks to this evidence gap. The primary aim is to assess feasibility of implementing routine frailty assessment in a reproducible outpatient setting. Secondary objectives include comparing prognostic values and interuser agreement across five frailty assessment tools. METHODS AND ANALYSIS: This single-centre prospective cohort study of feasibility is conducted in a rapid-referral vascular surgery clinic, serving a population of 2 million. Adults with capacity (>18 years), attending a clinic for any reason, are eligible for inclusion. Five assessments are completed by patient (Rockwood Clinical Frailty Scale (CFS) and Frail NonDisabled Questionnaire), clinician (CFS, Healthcare Improvement Scotland FRAIL tool and 'Initial Clinical Evaluation') and researcher (11-item modified Frailty Index). Consistent with feasibility objectives, outcome measures include recruitment rates, frailty assessment completion rates, time-to-complete assessments and interuser variability. Electronic follow-up at 30 days and 1 year will assess home-time and mortality as prognostic indicators. Patients treated surgically/endovascularly will undergo additional 30-day and 1-year postoperative follow-up, outcome measures include: surgical procedure, mortality, complications (according to Clavien-Dindo Classification), length of stay, readmission rates, non-home discharge, home-time, higher social care requirements on discharge and amputation-free survival. Prognostic value will be compared by area under receiver operating characteristic curves. Continuous outcome variables will be analysed using Spearman's rank correlation coefficient. Interuser agreement will be compared by percentage agreement in Cohen's kappa coefficient.  ETHICS AND DISSEMINATION: The study is sponsored by National Health Service Greater Glasgow and Clyde (R&IUGN23CE014). London-Riverside REC (23/PR/0062) granted ethical approval. Results will be disseminated through publication in peer-reviewed vascular surgery and geriatric medicine themed journals and presentation at similar scientific conferences. TRIALS REGISTRATION NUMBER: NCT06040658. Stage of study: pre-results.