Remote FEV1 Monitoring in Asthma Patients: A Pilot Study

Can At-Home Spirometry Replace Clinic Visits for Tracking Lung Function in Asthma?

Forced expiratory volume in one second (FEV1) is one of the most critical parameters for assessing lung function in asthma, yet it’s traditionally captured only during periodic clinic visits, despite asthma itself being defined by variable, fluctuating airflow obstruction. A pilot study published in Clinical and Translational Science, led by Koneksa Health in collaboration with the Medicines Evaluation Unit in Manchester and Regeneron Pharmaceuticals, tested whether mobile spirometry (mSpirometry) could fill that gap.

How the Study Was Designed

• Study population and protocol: Twelve patients with moderate asthma performed pulmonary function tests at home twice daily for 28 days, alongside weekly in-clinic assessments, at a single study center.
• Compliance: Mean subject compliance with mSpirometry was 70% for twice-daily testing and 85% for at least once-daily testing, demonstrating that sustained, frequent at-home spirometry is achievable for patients.
• Agreement with clinic measures: mSpirometry FEV1 values were highly correlated with same-day clinic measurements, both in the morning (r = 0.993) and afternoon (r = 0.988), with a smaller mean difference for afternoon readings (0.0019 L) than morning readings (0.0126 L).
• Test-retest reliability: Reliability, measured by intraclass correlation coefficient, was comparable between mobile (ICC = 0.932) and clinic (ICC = 0.942) spirometry.
• Statistical power gains: Simulation analysis showed that dense mSpirometry sampling could improve statistical power to detect a treatment effect compared to relying on sparse, periodic clinic measurements alone.

What This Means for Asthma Trial Design

This pilot study demonstrates that remote, patient-performed spirometry can match the reliability of clinic-based testing, while also capturing the day-to-day variability that defines asthma in the first place. For sponsors designing asthma trials, that combination of strong compliance, high agreement with clinic measures, and improved statistical power makes a compelling case for incorporating remote FEV1 monitoring as a primary or supportive endpoint, not just an exploratory add-on.

This is the kind of endpoint feasibility and agreement testing Koneksa Health builds into every respiratory digital biomarker program, validating that remote measures hold up against the clinical gold standard before they’re deployed at scale.

Reference: Huang C, Izmailova ES, Jackson N, et al. Remote FEV1 Monitoring in Asthma Patients: A Pilot Study. Clin Transl Sci. 2021;14(2):529-535. doi:10.1111/cts.12901. PMID: 33048470.