RT Journal Article
SR Electronic
T1 Managing asthma in the outpatient clinic - Can the FEV1/FVC indicate when to do a reversibility test?
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P2258
VO 40
IS Suppl 56
A1 Celeste Porsbjerg
A1 Asger Sverrild
A1 Lise Stensen
A1 Birgitte Nybo Jensen
A1 Backer Vibeke
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P2258.abstract
AB Background: Testing for reversibility to SABA often constitutes the first step of a diagnostic assessment of asthma. However, patients with a normal or near-normal lung function often do not have significant reversibility, and performing reversibility testing in these patients may not be cost-effective.Aim: To describe the value of the FEV1/FVC ratio using lower limit of normal (LLN) for predicting significant reversibility to SABA, and to define optimum cut-points that might be applied clinically.Methods: The MAPOut I study is a retrospective observational study of all patients consecutively referred to a tertiary hospital specialist clinic over a 12- month period, on suspicion of asthma (n=221).Results: In total, 122 subjects (55%) had a reversibility test performed, among whom 28 (23%) had a significant response to beta-2-agonist, defined as an increase in FEV1 of 12% or more, and at least 200 mL. The area under the curve of the FEV1/FVC % of the LLN for predicting reversibility was 0,76 (p<0,001). The FEV1/FVC ratio was above the LLN in 77% of newly referred asthma patients, including subjects who had a reversibility test performed (94/122 (77%)). Only 14% of subjects with an FEV1/FVC above the LLN had significant reversibility, compared to 54% of subjects with an FEV1/FVC ratio below the LLN.Conclusion: Absence of significant airflow obstruction at rest was associated with a low likelihood of reversibility to beta-2-agonist. The majority of subjects referred for specialist assessment on the suspicion of asthma did not have airflow obstruction. In these subjects, alternative diagnostic strategies may be more cost-effective.