Ability of patient-reported outcomes to predict progression-free survival in patients with mild to moderate fibrosing interstitial lung disease.

BACKGROUND

The prognostic utility of patient-reported outcomes (PROs) in mild to moderate fibrosing interstitial lung disease (FILD) remains insufficiently characterized.

METHODS

In this retrospective study, we examined the associations between PROs-Short-Form 36 (SF-36), Nagasaki University Respiratory Activities of Daily Living Questionnaire (NRADL), Hospital Anxiety and Depression Scale-Depression (HADS-D) and HADS-Anxiety (HADS-A)-and progression-free survival (PFS) in patients with FILD and a gender-age-physiology (GAP) score ≤5. We employed principal component analysis (PCA), hierarchical cluster analysis (HCA), and Cox proportional hazards modeling. PFS events were defined as a >10 % decline in forced vital capacity (FVC), >15 % decline in diffusing capacity for carbon monoxide (DLCO), acute exacerbation, or death from FILD.

RESULTS

Among 115 patients analyzed, PCA revealed that NRADL, select SF-36 subscales, and HADS-D correlated with age, gender, modified Medical Research Council scale, ILD-GAP score, FVC, DLCO, 6-min walk distance, and/or Chronic Obstructive Pulmonary Disease Assessment Test (CAT) score. HCA-based clustering of SF-36, NRADL, and HADS-D, and HADS-A-though not individual PRO measures-was independently associated with PFS. Additional independent predictors included lowest SpO2 during 6MWT, idiopathic pulmonary fibrosis diagnosis, and CAT score.

CONCLUSION

In patients with mild to moderate FILD, SF-36, NRADL, HADS-D, and HADS-A demonstrated associations with multiple clinical parameters. Clustering based on these PROs was significantly associated with PFS. These findings suggest that a multidimensional evaluation of health-related quality of life, activities of daily living, and mental status using PROs may offer valuable prognostic insights and support risk stratification in clinical practice.