Home Spirometry Has Potential for Detecting SSc-ILD Decline

TOPLINE:

Home spirometry shows potential for early detection of pulmonary function decline in patients with systemic sclerosis–associated interstitial lung disease (SSc-ILD). It shows good cross-sectional correlation with hospital tests, along with 60% sensitivity and 87% specificity for detecting progressive ILD.

METHODOLOGY:

• Researchers conducted a prospective, observational study to examine the validity of home spirometry for detecting a decline in pulmonary function in patients with SSc-ILD.
• They included 43 patients aged 18 years or older with SSc-ILD from two tertiary referral centers in the Netherlands who received treatment with immunosuppressives for a maximum duration of 8 weeks prior to baseline.
• All participants were required to take weekly home spirometry measurements using a handheld spirometer for 1 year, with 35 completing 6 months of follow-up and 31 completing 12 months.
• Pulmonary function tests were conducted in the hospital at baseline and semiannual visits.
• The primary outcome was the κ (kappa statistic) agreement between home and hospital measurements after 1 year to detect a decline in forced vital capacity (FVC) of 5% or more; the sensitivity and specificity of home spirometry were also evaluated to detect an absolute decline in FVC%, using hospital tests as the gold standard.

TAKEAWAY:

• Home spirometry showed a fair agreement with the pulmonary function tests conducted at the hospital (κ, 0.40; 95% CI, 0.01-0.79).
• Home spirometry showed a sensitivity of 60% and specificity of 87% in detecting a decline in FVC% predicted of 5% or more.
• The intraclass correlation coefficient between home and hospital FVC measurements was moderate to high, with values of 0.85 at baseline, 0.84 at 6 months, and 0.72 at 12 months (P
• However, the longitudinal agreement between home and hospital measurements was lower with a correlation coefficient of 0.55.

IN PRACTICE:

“These findings suggest that home spirometry is both feasible and moderately accurate in patients with systemic sclerosis–associated ILD. However, where home spirometry fell short was the low sensitivity in detecting a decline in FVC% predicted,” experts wrote in an accompanying editorial.

“The results of this study support further evaluation of the implementation of home spirometry in addition to regular healthcare management but do not endorse relying solely on home monitoring to detect a decline in pulmonary function,” study authors wrote.

SOURCE:

The study was led by Arthiha Velauthapillai, MD, Department of Rheumatology, Radboud University Medical Center, Nijmegen, the Netherlands, and was published online on November 8, 2024, in The Lancet Rheumatology.

LIMITATIONS:

The study might have been underpowered because of inaccuracies in initial assumptions, with a lower-than-anticipated prevalence of progressive ILD and a higher dropout rate. The study included only Dutch patients, which may have limited the generalizability of its findings to other settings with lower internet access or literacy rates.

DISCLOSURES:

This study was partly supported by grants from Galapagos and Boehringer Ingelheim. Some authors received grants or consulting or speaker fees from Boehringer Ingelheim, AstraZeneca, and other pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.