To determine the optimum series of investigations to diagnose asthma

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN11676160

Enrollment

300

Registered

2019-07-03

Start date

2018-12-03

Completion date

Unknown

Last updated

2026-04-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Asthma Respiratory

Interventions

The Rapid Access Diagnostics for Asthma (RADicA) study will aim to determine the optimum diagnostic pathway for asthma and to determine the optimum series of investigations to predict “steroid-respons

Eligibility

Sex/Gender

All

Age

5 Years to 70 Years

Inclusion criteria

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

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)

Design outcomes

Primary

Measure	Time frame
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.	—

Measure

Time frame

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

Measure	Time frame
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.	—

Measure

Time frame

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.

—

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Apr 17, 2026