A review of the challenges, learnings and future directions of home handheld spirometry in interstitial lung disease

Abstract

Background Patients with interstitial lung disease (ILD) require regular physician visits and referral to specialist ILD clinics. Difficulties or delays in accessing care can limit opportunities to monitor disease trajectory and response to treatment, and the COVID-19 pandemic has added to these challenges. Therefore, home monitoring technologies, such as home handheld spirometry, have gained increased attention as they may help to improve access to care for patients with ILD. However, while several studies have shown that home handheld spirometry in ILD is acceptable for most patients, data from clinical trials are not sufficiently robust to support its use as a primary endpoint. This review discusses the challenges that were encountered with handheld spirometry across three recent ILD studies, which included home spirometry as a primary endpoint, and highlights where further optimisation and research into home handheld spirometry in ILD is required. Abstract body Rate of decline in forced vital capacity (FVC) as measured by daily home handheld spirometry versus site spirometry was of primary interest in three recently completed studies: STARLINER (NCT03261037), STARMAP and a Phase II study of pirfenidone in progressive fibrosing unclassifiable ILD (NCT03099187). Unanticipated practical and technical issues led to problems with estimating FVC decline. In all three studies, cross-sectional correlations for home handheld versus site spirometry were strong/moderate at baseline and later timepoints, but longitudinal correlations were weak. Other issues observed with the home handheld spirometry data included: high within-patient variability in home handheld FVC measurements; implausible longitudinal patterns in the home handheld spirometry data that were not reflected in site spirometry; and extreme estimated rates of FVC change. Conclusions Home handheld spirometry in ILD requires further optimisation and research to ensure accurate and reliable FVC measurements before it can be used as an endpoint in clinical trials. Refresher training, automated alerts of problems and FVC changes, and patient support could help to overcome some practical issues. Despite the challenges, there is value in incorporating home handheld spirometry into clinical practice, and the COVID-19 pandemic has highlighted the potential for home monitoring technologies to help improve access to care for patients with ILD.

Present and future perspectives in early diagnosis and monitoring for progressive fibrosing interstitial lung diseases

“…In this study, estimating the rate of FVC decline proved difficult due to technical difficulties with the device and implausible measurements. Similar issues were encountered in two other studies aiming to describe ILD disease behavior using home spirometry (STARLINER and STARMAP) ( 29 ). Despite the limitations, high patient satisfaction with home spirometry monitoring has been reported ( 30 , 31 ).…”

“…A systematic review has shown that patient adherence to home spirometry was satisfactory (> 75%) and values measured at home correlated significantly with those measured in-hospital ( 26 ) Interestingly, the variability in home-measured FVC values may actually be an independent predictor for fibrotic ILD progression ( 27 ) Increasing adherence can be achieved by setting up automated email reminders when a measurement is not performed when expected ( 28 ), providing comprehensive initial and refresher training to patients, or using a spirometry schedule which is more acceptable (rather than daily measurements) ( 29 ). The optimal timing and frequency of testing to account for diurnal variation has not yet been established ( 30 ).…”

Study protocol: A comparison of mobile and clinic‐based spirometry for capturing the treatment effect in moderate asthma

“…Several groups have tested mSpirometry against in‐clinic spirometry in interventional studies of asthma and chronic obstructive pulmonary disease (COPD), demonstrating high correlations 9 and small mean differences 10 between the two modalities. On the other hand, Maher et al 11 reviewed the results of three clinical trials of interstitial lung disease that adopted mSpirometry and noted a range of practical and technical limitations, concluding that this technology requires further optimization in this lung disease.…”

Home monitoring to detect progression of interstitial lung disease: A prospective cohort study

“…4,5 Despite technical issues, 5 studies have demonstrated that home-spirometry can predict outcomes by monitoring the rate of decline in FVC, and its measures correlate with hospital-spirometry. 2,4,6 A significant gap remains in the current literature; specifically, there is scant evidence supporting the benefit of continuous monitoring of both physiological parameters and symptoms in detecting progression or response to treatment. 2,3,6 The potential of this approach to augment or replace in-hospital spirometry offers an interesting possibility.…”

“…2,4,6 A significant gap remains in the current literature; specifically, there is scant evidence supporting the benefit of continuous monitoring of both physiological parameters and symptoms in detecting progression or response to treatment. 2,3,6 The potential of this approach to augment or replace in-hospital spirometry offers an interesting possibility. This study evaluated a real-time multimodal program using commercially available technology to detect outcomes in ILD through continuous monitoring of physiological parameters and symptoms.…”