A Diagnostic Accuracy Study: N-Tidal Assessment for Respiratory Diagnosis Compared to Using Standard Testing
Trial ID: NCT07253883
Status: NOT_YET_RECRUITING
Study type: OBSERVATIONAL
Start date: 2026-04-01
Completion date: 2027-05-19
Sponsor: Liverpool Heart and Chest Hospital NHS Foundation Trust
Collaborators: TidalSense
Conditions: Asthma (Diagnosis); COPD (Chronic Obstructive Pulmonary Disease)
Interventions: Partial pressure of CO2 during tidal breathing; FENO; Spirometry
Locations: Liverpool Heart and Chest Hospital NHS Foundation Trust
Countries: United Kingdom
Enrollment: 1200
Age range: 18 Years - 110 Years
Sex: ALL

Summary:
The diagnosis of either asthma or chronic obstructive pulmonary disease (COPD) is currently based on a combination of symptoms, different lung tests and sometimes a 'trial by treatment'. Both COPD and Asthma tests currently include forced breathing using a test known as spirometry which can be difficult and uncomfortable for people to perform and needs expert interpretation. Asthma can require multiple tests in sequence which can make the process of diagnosis long and inconvenient for patients. In the UK, there have been challenges providing enough testing for COPD and asthma, in part because the tests are challenging to provide in the community to everyone who needs one.

The STARDUST study aims to test and develop new ways of diagnosing asthma and COPD that are quick, accurate and easy for patient and healthcare professionals to perform. People who have been referred for routine lung testing will breathe normally in and out into a handheld device called the N-Tidal Handset for 75 seconds. This device measures how the level of carbon dioxide (CO2) changes in the breath as people breath through it. The information gathered on the N-Tidal Handsets, called breath records or capnograms, will not be used to alter the diagnosis of any participants in the study.

After the capnograms have been collected, the research team will test 'algorithms' that have been developed using artificial intelligence, to see if they can accurately identify the correct diagnosis. Information collected in the study will also be used to make improvements in these algorithms.

If confirmed to be accurate, these algorithms could be used in clinical practice to help healthcare professionals make faster, more accessible and accurate diagnoses, especially in settings like GP clinics in the community where access to specialist tests may be limited.

Eligibility criteria:
Inclusion Criteria:

* Age ≥ 18 years
* Referred for respiratory diagnostic testing with a clinical suspicion of asthma or COPD
* Participant is willing and able to provide informed consent

Exclusion Criteria:

* Referred for respiratory diagnostic testing for a condition other than asthma or COPD, with no mention in the referral of a clinical suspicion of COPD or asthma
* Participants who, in the opinion of the chief investigator, or their delegate, are unlikely to comply with the requirements of the study
* Inability to give written informed consent
* Participants who are acutely unwell
* Patients unable to breathe through their mouths e.g. tracheostomy patients

Outcomes:
Diagnostic accuracy of the diagnostic algorithms of N-Tidal Diagnose 1; Diagnostic accuracy of prototype diagnostic algorithms