Fig. 1

Distribution of the study cohort across frailty status categories at each assessment point: one month before admission (Frail-VIG₀), within the first 48 h after admission (Frail-VIG₁), at discharge (Frail-VIG₂), and at 30-day post-discharge (Frail-VIG₃). Green: No frailty (Frail-VIG index score < 0.2). Yellow: mild frailty (Frail-VIG index score 0.2–0.35). Orange: moderate frailty (Frail-VIG index score 0.36–0.5). Red: advanced frailty (Frail-VIG index score > 0.5). Grey: death, White: missing values