The potential role of direct and indirect bronchial challenge testing to identify overtreatment of community managed asthma

Summary Background Although airway hyperresponsiveness (AHR) is a defining feature of asthma pathophysiology, bronchial challenge testing is not routinely used in primary care asthma management. Objective The aim of this study was to evaluate the potential role of direct (methacholine) and indirect (mannitol) challenge testing in community managed asthma. Methods Patients currently treated for asthma from Tayside and Fife 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, exhaled nitric oxide (FeNO); Asthma Control Questionnaire (ACQ) and Mini Asthma Quality of Life Questionnaire (AQLQ). Results A total of 3388 asthmatics were initially identified by HIC with 423 positive responses and 123 completing the study. Seventy percent had either a positive methacholine (PC20