Frailty and Comorbidity Burden as Predictors of Recurrent Hospitalization in Older Vietnamese Adults with Heart Failure: A Prospective Cohort Study

Figures

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  Fig. 1.. Screening, enrollment, and follow-up. Of 300 consecutive patients with chronic heart failure aged 60 years or older screened at the outpatient cardiology clinic of Thong Nhat Hospital between August 2024 and March 2025, 150 were excluded for the reasons shown. All 150 enrolled participants completed 12-month prospective follow-up and were classified by frailty status at baseline: 96 non-frail (CFS score <5) and 54 frail (CFS score ≥5). Baseline clinical and functional characteristics of this cohort have been reported in the companion cross-sectional study. CFS, Clinical Frailty Scale.

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  Fig. 2.. Distribution of all-cause hospitalizations over 12 months according to frailty status. (A) shows the proportion of patients in each hospitalization-count category (0, 1, 2, 3, 4, or ≥5 events) stratified by frailty status. (B) shows the total number of all-cause hospitalizations per patient, presented as a beeswarm plot overlaid on a box plot (median, interquartile range, and 1.5×interquartile range whiskers); individual observations are jittered to reduce overplotting. The p-value was derived from the Mann–Whitney U test. Frail patients were defined as those with a Clinical Frailty Scale score of 5 or higher.

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  Fig. 3.. Discriminative performance of prognostic models for recurrent all-cause hospitalization. (A) shows Harrell's C-statistic with 95% confidence intervals from Andersen–Gill recurrent event models for five predictor specifications: frailty alone, left ventricular ejection fraction (LVEF) classification alone, frailty plus LVEF, the frailty–Charlson Comorbidity Index (CCI) composite alone, and the composite plus LVEF. The dashed vertical line denotes chance discrimination (C-statistic=0.50). (B) shows the Akaike information criterion (lower values indicate better model fit) for the same five specifications estimated separately by the Andersen–Gill (red) and negative binomial (blue) estimators. Frailty was defined as a Clinical Frailty Scale score of 5 or higher; LVEF was classified as reduced (≤40%), mildly reduced (41%–49%), or preserved (≥50%); the frailty–CCI composite was constructed by cross-classifying frailty status with high versus low CCI, defined by the cohort median.