Abstract Rationale While prognosis in non-idiopathic pulmonary fibrosis, interstitial lung disease (non-IPF, ILD) vary by underlying cause and the extent and rate of fibrosis, the condition generally is chronic and progressive. Decline in lung function measured with forced vital capacity percent predicted (FVCpp) is a benchmark of progression. Estimating the real-world trajectory of FVCpp is challenging due to limited data and the association between testing frequency and patients’ health status. The objective of this study was to estimate FVCpp trajectory and terminal outcomes overall, and for clusters of real-world patients with non-IPF ILD. Methods Adults with newly diagnosed non-IPF, ILD were identified from the Truveta platform (1/2015-5/2025). Non-IPF, ILD was identified as ≥ 2 claims for fibrosis, or ≥ 1 claim for fibrosis and ≥1 claim for an underlying ILD condition within 365 days. The first non-IPF, ILD diagnosis was the index date. The follow-up period spanned the index date until the end of clinical activity or death. Patients had a baseline FVCpp value during the 12 months before or up to 60 days after the index date and a FVCpp value during the follow-up period, after the baseline value. Patients did not use antifibrotics before the index date. Clusters of patients with similar longitudinal patterns of FVCpp were identified using group-based trajectory modeling. FVCpp trajectory was estimated from the time of baseline FVCpp using a joint mixed model accounting for the frequency of FVCpp measurements and terminal outcomes (lung transplant or death) overall and in clusters. Time to terminal outcomes was described using Kaplan-Meier models. Results 5,325 patients were identified (mean age: 69.8 years old; female: 49.1%; mean baseline FVCpp: 76.4%; mean follow-up time: 46.1 months). Antifibrotics were subsequently initiated in 19.6% of the patients. Three clusters were identified. Cluster 1 included 52.3% of patients (mean age: 68.6 years old; female: 49.6%; mean baseline FVCpp: 75.9), cluster 2 included 24.3% of patients (mean age: 70.3 years old; female: 49.9%; mean baseline FVCpp: 73.0), cluster 3 included 23.4% of patients (mean age: 72.2 years old; female: 47.4%; mean baseline FVCpp: 81.0). Annual FVCpp absolute change was estimated as -0.32% (overall), -0.84% (cluster 1), 2.10% (cluster 2), and -6.30% (cluster 3). Time to terminal outcomes at 5 years was 76.6% (overall), 82.0% (cluster 1), 73.1% (cluster 2), and 64.5% (cluster 3). Conclusions These results demonstrate varying progressions in non-IPF, ILD that may be prognostic of terminal outcomes, highlighting the need for better patient monitoring. This abstract is funded by: Boehringer Ingelheim Pharmaceuticals, Inc.
Kharat et al. (Fri,) studied this question.