Disease Behaviour During the Peri-Diagnostic Period in Patients with Suspected Interstitial Lung Disease: The STARLINER Study

Disease behaviour may guide diagnosis and treatment decisions in patients with interstitial lung disease (ILD). STARLINER aimed to characterise disease behaviour in patients with suspected ILD during the peri-diagnostic period using real-time home-based assessments. STARLINER (NCT03261037) was an international, multicentre study. Patients ≥ 50 years old with suspected ILD were followed throughout the peri-diagnostic period, consisting of a pre-diagnostic period (from enrolment to diagnosis) and a post-diagnostic period (from diagnosis to treatment initiation). Study length was variable (≤ 18 months). The primary endpoint was time-adjusted semi-annual forced vital capacity (FVC) change measured during the peri-diagnostic period using daily home spirometry in patients with idiopathic pulmonary fibrosis (IPF). Secondary outcomes included changes in FVC (home spirometry) in patients with non-IPF ILD, changes in FVC (site spirometry), changes in physical functional capacity measured by daily home accelerometry and site 6-min walk distance (6MWD), and changes in patient-reported outcomes (PROs) in IPF or non-IPF ILD. Of the 178 patients enrolled in the study, 68 patients were diagnosed with IPF, 62 patients were diagnosed with non-IPF ILD, 9 patients received a non-ILD diagnosis and 39 patients did not receive a diagnosis. Technical and analytical issues led to problems in applying the prespecified linear regression model to analyse the home FVC data. Time-adjusted median (quartile [Q]1, Q3) semi-annual FVC change during the peri-diagnostic period measured using home and site spirometry, respectively, was – 147.7 (– 723.8, 376.2) ml and – 149.0 (– 314.6, 163.9) ml for IPF and 19.1 (– 194.9, 519.0) ml and – 23.4 (– 117.9, 133.5) ml in non-IPF ILD. A greater decline in steps per day was observed for IPF versus non-IPF ILD, whereas an increase in 6MWD was observed for patients with IPF versus a decline in 6MWD for patients with non-IPF ILD. No clear patterns of disease behaviour were observed for IPF versus non-IPF ILD for PROs. Despite home spirometry being feasible for most patients and centres, technical and analytical challenges in the home-based assessments prevented firm conclusions regarding disease behaviour. This highlights that further optimisation of the technology and analysis methods is required before widespread implementation. NCT03261037.