At‐Home Versus in‐Clinic Vital Capacity Measurement: Insights From the
                    <scp>HEALEY ALS</scp>
                    Platform Trial

doi:10.1002/mus.70322

DOI: 10.1002/mus.70322 ISSN: 0148-639X

At‐Home Versus in‐Clinic Vital Capacity Measurement: Insights From the HEALEY ALS Platform Trial

Eric A. Macklin, James D. Berry, Brittney A. Harkey, Lindsay Heyd, Marianne Chase, Hong Yu, Alexander V. Sherman, Derek Dagostino, Gale Kittle, Meghan Hall, Mariah R. Connolly, Kristin Drake, Elisa Giacomelli, Erica Scirocco, Saloni Sharma, Suma Babu, Michael Benatar, Zachary Simmons, Eufrosina Young, Merit E. Cudkowicz, Jeremy Shefner, Sabrina Paganoni,

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ABSTRACT

Introduction/Aims

Respiratory weakness, typically monitored as vital capacity (VC), is a central feature of amyotrophic lateral sclerosis (ALS). VC is increasingly measured remotely in participants' homes, although in‐clinic assessment remains the standard. We tested concordance between at‐home and in‐clinic VC to determine trial eligibility, track progression, and predict survival in a large ALS trial.

Methods

At‐home and in‐clinic VC were assessed at baseline and approximately every 8 weeks for a year in the first four regimens of the HEALEY ALS Platform Trial. At‐home assessments were coached via live videoconference and centrally reviewed. VC measurements, expressed as percent of predicted normal (% PN ), were compared cross‐sectionally, longitudinally, and for predicting survival time. Data from 233 participants with 3–8 paired at‐home and in‐clinic VC assessments completed < 14 days apart were analyzed.

Results

At‐home and in‐clinic VC were well correlated (Lin's r _c = 0.82) with no systematic bias. At‐home VC ≥ 60% PN predicted in‐clinic VC ≥ 60% PN with a positive predictive value of 91% and a negative predictive value of 65%. VC slopes were moderately correlated ( r _c = 0.68). At‐home VC progressed 28% faster than in‐clinic VC with proportionately less variance (at‐home [ SE ] = −1.882 [0.153] % PN /month, in‐clinic = −1.476 [0.131] % PN /month). Slopes of at‐home and in‐clinic VC explained 15% and 17% of variation in future survival time, respectively.

Discussion

At‐home and in‐clinic VC were well correlated cross‐sectionally. At‐home VC performed well tracking longitudinal change and predicting survival. The reduced participant burden of assessment and concordance with in‐clinic measurement support use of at‐home monitoring of VC.