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

The COVID-19 pandemic identified an urgent need to re-evaluate the provision of spirometry for clinical monitoring. Home spirometry offers the opportunity for real-time disease evaluation without risk of nosocomial infection. To determine the utility of home spirometry in interstitial lung disease (ILD), interim data from the ongoing INJUSTIS study was evaluated. High correlation was observed between home and hospital spirometry at baseline(r=0.89) and three-months(r=0.82). Over 90% of home spirometry values were within Bland-Altman agreement limits at both time points, although frequently underestimated hospital values. Home spirometry is feasible in people with fibrotic ILD. ### Competing Interest Statement CE is an employee, director and shareholder of patientMpower Ltd. ### Clinical Trial NCT03670576 ### Clinical Protocols ### Funding Statement Nottingham National Institute for Health Research (NIHR) Biomedical Research Centre. RGJ is supported by an NIHR Research Professorship (RP-2017-08-ST2-014). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: National Research Ethics Committee Nottingham (18/EM/0139 All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Ongoing study