Home spirometry in patients with idiopathic pulmonary fibrosis: data from the INMARK trial

Abstract

Data from the INMARK trial were used to investigate the feasibility and validity of home spirometry as a measure of lung function decline in patients with idiopathic pulmonary fibrosis (IPF).Subjects with IPF and preserved forced vital capacity (FVC) were randomised to receive nintedanib or placebo for 12 weeks followed by open-label nintedanib for 40 weeks. Clinic spirometry was conducted at baseline and weeks 4, 8, 12, 16, 20, 24, 36 and 52. Subjects were asked to perform home spirometry at least once a week and ideally daily. Correlations between home- and clinic-measured FVC and rates of change in FVC were assessed using Pearson correlation coefficients.In total, 346 subjects were treated. Mean adherence to weekly home spirometry decreased over time but remained above 75% in every 4-week period. Over 52 weeks, mean adherence was 86%. Variability in change from baseline in FVC was greater when measured by home rather than clinic spirometry. Strong correlations were observed between home- and clinic-measured FVC at all time-points (r=0.72 to 0.84), but correlations between home- and clinic-measured rates of change in FVC were weak (r=0.26 for rate of decline in FVC over 52 weeks).Home spirometry was a feasible and valid measure of lung function in patients with IPF and preserved FVC, but estimates of the rate of FVC decline obtained using home spirometry were poorly correlated with those based on clinic spirometry.

Worldwide experiences and opinions of healthcare providers on eHealth for patients with interstitial lung diseases in the COVID-19 era

“…Most HCPs have no staff available to instruct patients and follow up results, and reimbursement for eHealth is lacking. Technical and analytic issues were encountered in previous home spirometry studies (14,15). This is consistent with our survey results, with technical issues being the most frequently reported hurdle.…”

A comparison of clinic and home spirometry as longtudinal outcomes in cystic fibrosis

“…Longitudinal evaluations of home spirometry have been conducted in related diseases and spirometric outcomes. Studies of forced vital capacity in idiopathic pulmonary fibrosis have pointed out that longitudinal outcomes may differ even if home and clinic spirometry are cross sectionally similar [ 18 , 19 ]. One of these studies concluded that the greater variability of home spirometry would require greater sample sizes to maintain power [19] , while the other calculated that if the frequency of home spirometry is sufficiently high, that may yield superior longitudinal precision [18] .…”

“…Studies of forced vital capacity in idiopathic pulmonary fibrosis have pointed out that longitudinal outcomes may differ even if home and clinic spirometry are cross sectionally similar [ 18 , 19 ]. One of these studies concluded that the greater variability of home spirometry would require greater sample sizes to maintain power [19] , while the other calculated that if the frequency of home spirometry is sufficiently high, that may yield superior longitudinal precision [18] . In a recent phase 3 randomized, placebo-controlled interventional trial in Duchenne muscular dystrophy (DMD) whereby both clinic and home spirometry were captured longitudinally over a year-long study, a retrospective study was performed to evaluate the comparability of treatment effect estimates derived from home vs. clinic-based peak expiratory flow [10] .…”

Clinical utility of home versus hospital spirometry in fibrotic ILD: evaluation following INJUSTIS interim analysis

“…Although participants were blinded, adherence to daily spirometry remained high, and was similar to adherence rates in non-blinded studies(13). We stipulated the performance of daily measures rather than a minimum number of weekly blows,(8, 9) with reliable adherence in the three-month design. Home and hospital measurements were highly correlated at complementary time points, though home spirometry tended to underestimate measurements when compared with hospital spirometry(7).…”