Abstract

Aim
Spirometry is the current gold standard for COPD diagnosis, but is difficult for patients, time-consuming, and requires specialist training to perform and interpret leading to variable access and quality across the UK. This contributes to approximately 1.5 million patients who remain undiagnosed and therefore without treatment.
TidalSense has developed N-Tidal® Diagnose, a CE-marked point-of-care diagnostic solution for COPD, which combines the precise measurement of respiratory physiology using the N-Tidal® Handset with automated interpretation of the data using diagnostic AI algorithms. The CORMORANT study will evaluate the diagnostic performance and acceptability of N-Tidal Diagnose in primary care, compared to spirometry.
Method
CORMORANT is a post-market diagnostic accuracy study funded by NIHR Invention for Innovation (i4i) as a collaboration between industry, academia, patients, and the NHS. We will recruit 500 adults aged ≥35 years who have been referred for diagnostic spirometry for suspected COPD, across 24 primary care sites, including Community Diagnostic Centres.
The study pathway integrates closely with standard care and cause minimal interruption for patients or healthcare professionals (HCPs). At their usual care appointment, participants will use N-Tidal Diagnose prior to spirometry, having completed consent and questionnaires online. In a nested qualitative interview sub-study, a selection of participants and HCPs will be interviewed to explore the feasibility and acceptability of the device.
Results
The first participant is expected in July 2025. The primary outcome is diagnostic accuracy of N-Tidal Diagnose (index test) compared to consensus expert panel diagnosis of COPD using usual care spirometry (reference test). Secondary outcomes include quality assessment and comparison with primary care diagnosis. Qualitative findings will provide insights into the practical application of the device and any barriers or facilitators to primary care implementation.
Conclusion
If N-Tidal Diagnose were found to be accurate and acceptable compared to spirometry, it could offer an alternative to spirometry for diagnosing COPD in primary care. Earlier detection and treatment could improve patient outcomes, reduce costs, and alleviate burdens on the NHS. Findings from this study will inform health economic work later in the CORMORANT programme and provide evidence to inform potential implementation of N-Tidal Diagnose into primary care.