Predictive Value of Home Spirometry for Disease Progression in Patients With Idiopathic Pulmonary Fibrosis

초록

RATIONALE: Monitoring disease progression (DP) in idiopathic pulmonary fibrosis (IPF) is essential for optimizing treatment strategies. While home spirometry has been proposed as a practical tool for tracking lung function, its predictive value for DP remains unclear, particularly in patients with IPF. We investigated the predicting ability of home spirometry for DP in patients with IPF.METHODS: We conducted a multicenter, prospective cohort study involving 120 patients with IPF across 12 institutions in South Korea over a one-year period. Participants were instructed to perform home spirometry using the SPROLENIS device (JNBIO, South Korea) twice daily, at 8:00 AM and 8:00 PM, for five consecutive days each season, with a total observation period of nine months. Home spirometry data collected included forced vital capacity (FVC), the number of tests conducted, and the timing of each measurement. Disease progression (DP) was defined as a ≥10% absolute decline in FVC or a ≥15% decline in diffusing capacity for carbon monoxide (DLco) by on-site pulmonary function tests. The association between baseline variability, 3-month changes in home FVC, and DP was assessed using unadjusted and adjusted Cox proportional hazards models.RESULTS: Out of 120 patients (mean age: 68.4 years, 85% male), 23% experienced DP during the one-year follow-up. Baseline FVC variability from home spirometry, including standard deviation (HR=1.060, 95% CI=1.022-1.099) and coefficient of variation (HR=1.037, 95% CI=1.012-1.063), was significantly associated with DP. Both absolute (HR=0.888, 95% CI=0.834-0.945) and relative (HR=0.917, 95% CI=0.879-0.956) 3-month changes in home FVC were inversely associated with DP risk in adjusted analyses, indicating that a decalin in home FVC at 3-months was linked to higher DP risk (Table). A ≥5% decline in home FVC over 3 months was associated with an increased the risk of DP (HR=6.517, 95% CI=2.620-16.213) in absolute terms and in relative terms (HR=2.759, 95% CI=1.139-6.687) in adjusted analyses. Declines of ≥10% were also associated with an increased risk in absolute terms (HR=10.750, 95% CI=3.004-38.464) and in relative terms (HR=7.239, 95% CI=2.707-19.355) in multivariable analysis. On-site spirometry measurements, including baseline FVC and 3-month changes, were not significantly associated with DP in both unadjusted and adjusted analyses.CONCLUSIONS: Our data suggested that variability and short-term changes in home FVC are valuable predictors of DP, suggesting was associated with DP in patients with IPF, and the predictive role of home spirometry for DP.