TOPLINE:

Home spirometry showed promise in diagnosing asthma, with nearly 80% of patients receiving a diagnosis within 2-4 weeks. Two days of positive diurnal variability in forced expiratory volume or peak expiratory flow significantly improved diagnosis.

METHODOLOGY:

• Researchers in Sweden conducted a real-world clinical study involving 123 participants (mean age, 33 years; 67% females) with asthma-like symptoms to evaluate the diagnostic accuracy of dynamic spirometry with bronchodilator responsiveness testing and remote diurnal variability testing for asthma.
• Participants recruited from seven primary healthcare centres underwent home spirometry through forced expiratory volume, peak expiratory flow, and bronchodilator responsiveness testing for 2-4 weeks using AsthmaTuner.
• AsthmaTuner provided automated clinical decision support, offering feedback on asthma control and medication plans on the basis of spirometry results. Spirometry measurements were performed either in the clinic or remotely.
• For inconclusive cases, participants were randomly assigned to either use spirometry with a self-management module or receive usual care for trial treatment for at least 3 months, and a new bronchodilator responsiveness testing was performed.
• Doctors made independent asthma diagnoses on the basis of clinical assessments and diagnostic tests, including a 3-month trial treatment with inhaled corticosteroids for uncertain cases.

TAKEAWAY:

• The study found that 58% of participants were diagnosed with asthma. Two days of positive diurnal variability testing provided the best combination of sensitivity and specificity for the diagnosis of asthma.
• Home spirometry demonstrated a sensitivity of 76% and a specificity of 69% for peak expiratory flow variability in asthma diagnosis. Bronchodilator responsiveness testing showed a high specificity (100%) but a low sensitivity (8.5%) for asthma diagnosis.
• Trial treatment with inhaled corticosteroids among participants with initially unclear diagnoses (n = 26) led to an asthma diagnosis in 23% of them.
• No adverse events were reported from the use of the home spirometry system for variability testing or self-management.

IN PRACTICE:

"The findings of this study support the integration of home spirometry into routine diagnostic workflows in primary care as a complementary tool to enhance the accuracy of asthma diagnosis," the authors wrote. "This streamlined approach has the potential to expedite the diagnostic process with use of remote home spirometry system, allowing individuals experiencing asthma symptoms to receive more timely treatment and then to later undergo in-office procedures like BDR [bronchodilator responsiveness testing] to get more detailed information on the severity of bronchial obstruction," they added.

SOURCE:

This study was led by Lynnea Myers, Karolinska Institutet, Stockholm, Sweden. It was published online on December 26, 2025, in npj Primary Care Respiratory Medicine.

LIMITATIONS:

This study was performed in a single region in Sweden, which may have limited the generalisability of the findings. Variability in doctors' diagnostic expertise in diagnosing asthma and the lack of specialised training may have affected the diagnostic accuracy. This study did not utilise certain diagnostic tests, such as blood eosinophil counts and bronchial challenge tests, which are typically performed in secondary care settings.

DISCLOSURES:

This study was funded by Vinnova, ALF medicine of Region Stockholm, and the Swedish Heart and Lung Foundation. Myers reported receiving funding from Forte Sweden. Additional disclosures are noted in the original article.

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