Asthma Algorithm May Miss Cases in Children: ERS 2026

The 2021 European Respiratory Society (ERS) diagnostic algorithm may fail to identify a substantial proportion of school-age children with asthma in clinical practice, according to research presented at the ERS Congress 2026.

In a multicentre Swiss cohort, the algorithm demonstrated high specificity but low sensitivity when compared with the final diagnosis made by physicians. The findings suggest that additional bronchial challenge testing may be valuable in children with suspected asthma despite normal spirometry and fractional exhaled nitric oxide (FeNO).

Assessing the ERS Asthma Algorithm

Diagnosing asthma in children can be challenging, particularly when symptoms are not accompanied by abnormalities on routine respiratory testing.

The 2021 ERS diagnostic algorithm for school-age asthma uses objective assessments including spirometry, bronchodilator reversibility (BDR), FeNO, and bronchial challenge tests.

Researchers evaluated its diagnostic performance using data from children aged 5–17 years referred with suspected asthma to eight paediatric pulmonology clinics participating in the Swiss Paediatric Airway Cohort.

Of 1,938 children referred with suspected asthma, 1,320 had sufficient test results for the ERS algorithm to be applied. Their median age was 10 years, and 56% were male.

The diagnosis generated by the algorithm was compared with the physician’s final diagnosis as the reference standard.

Algorithm Identifies Fewer Asthma Cases

Among children included in the analysis, 66% received a physician diagnosis of asthma. In contrast, the ERS algorithm classified only 23% as having asthma.

Compared with physician diagnosis, the algorithm had a sensitivity of 33% and specificity of 95%. Its positive predictive value was 93%, indicating that children classified as having asthma by the algorithm were highly likely to have also received a physician diagnosis.

However, the negative predictive value was only 43%, reflecting the large number of children with a physician diagnosis of asthma who were not classified as having the condition by the algorithm.

Normal Tests May Not Rule Out Asthma

Most false-negative cases occurred among the 878 children who had both normal spirometry and FeNO. Under the ERS algorithm, these findings do not indicate asthma or the need for further testing, and clinicians are directed towards considering alternative diagnoses.

However, 648 children within this group subsequently underwent bronchial challenge or BDR testing, and 503 were ultimately diagnosed with asthma.

The researchers concluded that although the ERS algorithm demonstrated high specificity, its low sensitivity could limit its ability to identify school-age asthma in this clinical cohort.

The findings suggest clinicians may need to consider bronchial challenge testing when asthma remains clinically suspected despite normal spirometry and FeNO results.

Reference

Sasaki M et al. Performance of the 2021 ERS diagnostic algorithm for school-age asthma. ERS Congress, 6-9th September 2026.