The potential role of bronchial challenge testing to identify overtreatment of community managed asthma
A. Manoharan, B. Lipworth, E. Craig, C. Jackson (Dundee, St Andrews, United Kingdom)
Source: International Congress 2014 – Phenotyping and monitoring asthma and COPD
Session: Phenotyping and monitoring asthma and COPD
Session type: Oral Presentation
Number: 1693
Disease area: Airway diseases
AbstractIntroduction: Bronchial hyperresponsiveness is a defining feature of asthma and is measured by bronchial challenges which are not routinely used in primary care.Aim: To evaluate the potential role of direct (methacholine) and indirect (mannitol) challenge testing in primary care.Methods: Community managed asthmatics were identified by the Health Informatics Centre (HIC) and invited to take part in the study. At screening the following tests were carried out: spirometry, methacholine and mannitol challenge; FeNO, Asthma Control Questionnaire (ACQ-6) and Asthma Quality of Life Questionnaire (MiniAQLQ).Results: 3388 asthmatics were identified by HIC with 423 positive responses and 123 completing the study. 70% had either a positive methacholine (PC20<8mg/ml) or mannitol challenge (PD15<635mg) and 30% were non-responsive to both challenges. 14% of methacholine responders were negative to mannitol and 16% of mannitol responders were negative to methacholine. Spirometry, FeNO, ACQ and AQLQ were significantly better in the non-responder group who were exposed to high ICS dose and frequent LABA.Patient characteristics according to bronchial challenge response | | Responders N=86 | Non-responders N=37 | P-value |
|---|
| Age(yrs) | 46(43-49) | 51(47-55) | 0.047 | | ICS dose(BDP equivalent,ug) | 500(400-1000) | 1000(400-1000) | 0.08 | | LABA(%) | 64 | 68 | 0.70 | | FEV1(%) | 88(85-91) | 100(95-104) | <0.001 | | FeNO(ppb) | 26(21-32) | 16(13-20) | 0.003 | | ACQ-6 | 1.07(0.90-1.24) | 0.55(0.32-0.77) | <0.001 | | MiniAQLQ | 5.59(5.37-5.81) | 6.05(5.78-6.33) | 0.015 |
Conclusions: We found that 30% of patients with community managed asthma were challenge negative and also appeared to be overtreated, in turn suggesting the need for supervised step-down.
Data presented as means(95% CI) except ICS dose as median(IQR) |