Discriminatory ability of gas chromatography-ion mobility spectrometry to identify patients hospitalised with COVID-19 and predict prognosis

Background Tests that can diagnose COVID-19 rapidly and predict prognosis would be significantly beneficial. We studied the ability of breath analysis using gas chromatography-ion mobility spectrometry (GC-IMS) for diagnosis of COVID-19 and as a predictor for subsequent requirement for Continuous Positive Airway Pressure (CPAP).\n\nMethods We undertook a single centre prospective observational study in patients with COVID-19, other respiratory tract infections and healthy controls. Participants provided one breath sample for GC-IMS analysis. We used cross validation analysis to create models that were then tested against the original cohort data. Further multivariable analysis was undertaken to adjust for differences between the comparator groups.\n\nResults Between 01/02/2021 and 24/05/2021 we recruited 113 participants, of whom 72 (64%) had COVID-19, 20 (18%) had another respiratory tract infection and 21 (19%) were healthy controls. Differentiation between patients with COVID-19 and healthy controls, and patients with COVID-19 and those with other respiratory tract infections, was achieved with high accuracy. Identification of patients with subsequent requirement for CPAP was completed with moderate accuracy and was not independently associated on multivariable analysis.\n\nConclusions We have shown that GC-IMS has a high capability to distinguish between acute COVID-19 infection and other disease states. Breath analysis shows promise as a predictor of subsequent requirement for CPAP in hospitalised patients with COVID-19. This platform has considerable benefits due to the test being rapid, non-invasive and not requiring specialist laboratory processing.\n\n### Competing Interest Statement\n\nThe authors have declared no competing interest.\n\n### Funding Statement\n\nThis study did not receive any funding\n\n### Author Declarations\n\nI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.\n\nYes\n\nThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:\n\nThe study had ethical approval from the West Midlands Research Ethics Committee (REC Reference 20/WM/0153). It was conducted in accordance with ICH-GCP, Declaration of Helsinki and the Data Protection Act 1998 and NHS Act 2006. All participants gave written, informed consent prior to any study procedures.\n\nI confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.\n\nYes\n\nI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).\n\nYes\n\nI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.\n\nYes\n\nAll data relevant to the study are included in the article or uploaded as supplementary information