The Long-Term Prognostic Impact of Clinical Frailty Scale on Acute Exacerbation of Fibrotic Interstitial Lung Disease

<bold>Introduction:</bold> Acute exacerbations of fibrotic interstitial lung disease (AE-fILD) are associated with high mortality and poor prognostic outcomes, yet factors influencing long-term prognosis have not been sufficiently explored. This study assessed the Clinical Frailty Scale (CFS), a simple and validated tool for frailty evaluation in elderly patients, to determine its predictive value in the longer-term outcomes after AE-fILD. <bold>Methods:</bold> We retrospectively analyzed fILD patients admitted for their first AE-fILD episode at Kobe City Medical Center General Hospital from January 2017 to May 2023. Based on medical chart data, patients were categorized into high (5-9) and low (1-4) CFS groups, with scores ranging from 1 (very fit) to 9 (terminally ill) prior to admission. The association between CFS and one-year post-admission mortality was evaluated using a multivariable Cox proportional hazards model, accounting for potential confounders. <bold>Results:</bold> 118 patients with AE-fILD were included. CFS was high in 50/118 (42%) patients and low in 68/118 (58%) patients. Median age was 79 (74-85 years) in high CFS and 78 (71-82 years) in low CFS patients. Within one year, 34/50 (68%) in the high CFS group and 30/68 (44%) in the low CFS group died. With adjustment for age (>75 years), serum LDH (>330 U/L), home oxygen therapy, SpO2/FIO2 ratio (≧235) at admission, the hazard ratio for mortality was 2.0(95% Cl 1.2-3.4) for high CFS. <bold>Conclusions:</bold> Our study reveals that the high CFS group has a poorer long-term prognosis following AE-fILD compared to the low CFS group. These results suggest that CFS can be a valuable tool for evaluating the long-term prognosis of patients with AE-fILD.