To determine the optimum series of investigations to diagnose asthma

Not Applicable

• Conditions: Asthma; Respiratory

• Registration Number: ISRCTN11676160
• Lead Sponsor: Manchester University NHS Foundation Trust

Brief Summary

2024 Results article in https://pubmed.ncbi.nlm.nih.gov/39296585/ (added 19/09/2024) 2024 Results article in https://pubmed.ncbi.nlm.nih.gov/39296585/ Asthma diagnosis: a comparison of established diagnostic guidelines in adults with respiratory symptoms (added 20/09/2024)

Detailed Description

Not available

Study Timeline

• Study Start: 2019-07-03
• Last Update Posted: 29 July 2024
• Study Completion: 2027-12-31

Recruitment & Eligibility

• Status: Ongoing
• Sex: All
• Target Recruitment: 300

Inclusion Criteria

1. Males and females >= 5 years and <70 years
2. Clinical suspicion of asthma from GP or referring health care professional
3. One or more symptom in keeping with asthma (i.e., cough, wheeze, chest tightness and breathlessness)
4. Capable of giving informed consent or where under 16 years attends with parent or legal guardian.
5. Participants must be able to communicate well in English

Exclusion Criteria

1. Pregnant women
2. Current ICS (used within previous 2 weeks) or oral steroid treatment (within the previous 4 weeks)
3. Former/Current smokers if > 10 pack year smoking history
4. Other relevant comorbidities (e.g., other lung disease; CF, COPD, ILD or bronchiectasis)
5. Recent antibiotic treatment within previous 2 weeks (these participants may be able to enter the study at a later date)

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Large airway function measured using: 1. Spirometry (FEV1, FVC, MEF25-75) at visits 1, 3, 4.2. BDR (? FEV1 or FVC following 400mcg inhaled Salbutamol) at visit 1.3. FeNO (NO ppb) at visits 1-4.4. PEFv (variability measured twice daily over 2 weeks)5. BHRmann (mannitol PD15) at optional visit 1.6. BHRmeth (Methacholine PD20) at visits 2, 4.Small airway function measured using:1. IOS (Rrs5Hz, Rrs20Hz, R5-20, Xrs5Hz, Xrs 20Hz, X5-20) at visits 1-4.2. MBW (LCI, Scond, Sacin) at visits 1-4.

Secondary Outcome Measures

Name	Time	Method
1. Asthma symptoms measured using Asthma Control Questionnaire (ACQ-5) at visits 1-4.2. Experimental biomarkers of small airway inflammation measured using:2.1 PExA at visits 1-4.2.2 VOC at visits 1-4.3. Blood tests including: Blood eosinophil count, cell culture, immune cell count, measures of immune cell activation (Mbd2, CCL17, CCR4) YKL-40 (CHI3L1), AMCase (CHIA), Chitotriosidase (CHIT1) at visits 1, 3, 4.4. Sputum eosinophil at visits 2, 4.