First-Line Diagnostic Investigations for Suspected Adult Asthma

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

• Ages 16 years and older
• All sexes
• Healthy volunteers accepted
• Child, Adult, Older adult

Study population: Potential participants will be identified from adults referred to the Physiological Sciences Department at George Eliot Hospital NHS Trust for objective investigation of suspected asthma through routine primary or secondary care referral pathways. Eligible participants will be assessed by the research team. Only patients who provide written informed consent will be enrolled into the study. Following consent, the lead researcher will access relevant electronic healthcare records to collect the clinical information required for the study, as described in the consent form. Study data will be assigned a unique pseudonymised study identification number and stored securely, password-protected, on the Trust's systems. Access to identifiable information will be restricted to authorised members of the research team in accordance with the UK GDPR, the Data Protection Act 2018 and NHS information governance policies.

Trial locations and contacts

1 site in 1 country.

About this study

Official title: Comparative Diagnostic Accuracy of First-line Objective Tests for Asthma in Adults With Suspected Disease: Evaluation of Individual and Combined Tests, and the Impact of Normal Spirometry and Obesity.

Conditions

Asthma (Diagnosis)

Being tested

Spirometry, Fractional Exhaled Nitric Oxide, bronchodilator response, oscillometry, Bronchial Provocation challange test

Medical subject headings

Asthma, Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

• SpirometryDiagnostic test

  Participants will undergo standardised pre-bronchodilator spirometry using a calibrated spirometer operated by trained study personnel. Measurements will include forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), slow vital capacity (SVC), peak expiratory flow (PEF) and the FEV₁/FVC ratio. Participants will perform at least three acceptable forced expiratory manoeuvres, with the highest reproducible values recorded. Spirometry will be conducted at the protocol-specified study visit(s) to assess pulmonary function as an outcome measure. Testing will follow current international quality control and acceptability standards.

• Fractional Exhaled Nitric OxideDiagnostic test

  Participants will undergo FeNO measurement using a calibrated nitric oxide analyser operated by trained study personnel. The test will be performed according to standardised international guidelines using a controlled exhalation at a constant flow rate. FeNO values, expressed in parts per billion (ppb), will be recorded to assess airway inflammation. Measurements will be obtained at protocol-specified study visit(s) under standardised testing conditions, with quality control procedures followed throughout testing.

• bronchodilator responseDiagnostic test

  Participants will undergo bronchodilator response testing to assess for airway responsiveness in both obstructive and normal patients. Spirometry will be performed before and after administration of a standardised dose of an inhaled short-acting bronchodilator delivered via a metered-dose inhaler with a spacer. Post-bronchodilator spirometry will be conducted after the protocol-specified waiting period. Changes in forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and other spirometric parameters will be recorded according to standardised international guidelines. Testing will be performed by trained study personnel using calibrated equipment.

• oscillometryDiagnostic test

  Participants will undergo respiratory oscillometry using a calibrated oscillometry device operated by trained study personnel. Measurements will be obtained during quiet tidal breathing according to standardised international guidelines. Respiratory impedance parameters, including airway resistance (e.g., R5, R20), reactance (e.g., X5), resonant frequency (Fres), and area of reactance (AX), will be recorded. At least three acceptable measurements meeting quality control criteria will be obtained. Testing will be performed at protocol-specified study visit(s) under standardised conditions to assess respiratory mechanics.

• Bronchial Provocation challange testDiagnostic test

  Participants will undergo a standardised bronchial provocation challenge to assess airway hyperresponsiveness. Increasing doses of a bronchial provoking agent will be administered according to a standardised protocol under the supervision of trained study personnel. Spirometry will be performed after each dose to measure changes in forced expiratory volume in one second (FEV₁). The test will continue until a predefined decline in FEV₁ is achieved or the maximum protocol dose is reached. Testing will be performed using calibrated equipment with continuous monitoring and appropriate safety procedures, following current international guidelines.

What is being measured

The primary outcome is the main question the study is designed to answer.

1. Primary outcome measure- Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, and Area Under the ROC Curve of Combined First-Line Objective Testing for Asthma Diagnosis

   Diagnostic performance of combined first-line objective investigations (fractional exhaled nitric oxide [FeNO], oscillometry, spirometry, and bronchodilator reversibility testing) compared with the composite reference standard incorporating bronchial provocation testing. Diagnostic performance will be assessed using sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC).

   Measured: 6 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1. First posted28 Aug 2026
2. Study start2 Aug 2026
3. Primary completion27 Feb 2028 (estimated)
4. Study completion30 Jul 2028 (estimated)

Resources

• Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
• Other trials for Asthma (Diagnosis)Studies of the same condition, open and under way.
• What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.