Time to diagnosis and long-term outcomes for adults presenting with breathlessness

Background: There are known delays to diagnosis for diseases which commonly present with chronic breathlessness, but the subsequent impact is unknown. For adults presenting with breathlessness, we investigated the time taken to achieve an explanatory diagnosis, and associations with unplanned hospitalisation and mortality. Methods: A retrospective cohort study using the UK CPRD was conducted involving adults with a first-recorded code for breathlessness and no pre-existing cardiorespiratory disease. We documented whether an explanatory diagnosis was recorded after the first code of breathlessness within two years and during all follow-up, and the time to diagnosis. Cox regression (adjusted) was used to investigate the associations with unplanned hospitalisation and mortality. Results: 101369 adults were included with a first-recorded code for breathlessness. After two-years, 43394 (43%) adults received a recorded explanatory diagnosis and had a higher risk of unplanned hospitalisation (1.25 [1.19-1.31]) and mortality (2.06 [1.60-2.65]) compared to adults without a diagnosis. Overall, 66909 (66%) adults received a recorded diagnosis during a median of 5-years follow-up. Adults that received a recorded diagnosis after ≥6 months had worse outcomes of unplanned hospitalisation (6-24 months: 1.01 [0.94-1.08]; ≥24 months: 1.13 [1.06-1.20]) and mortality (6-24 months: 3.38 [2.21-5.18]; ≥24 months: 10.80 [7.46-15.70]). Conclusion: We describe a sub-group of adults coded for breathlessness but without an explanatory diagnosis with better outcomes. However, in adults with an explanatory diagnosis waiting beyond six months was associated with worse outcomes. Diagnostic pathways for chronic breathlessness need to differentiate between these two groups and achieve earlier diagnosis in those at higher risk. ### Competing Interest Statement KK is supported by the National Institute for Health Research (NIHR) Applied Research Collaboration East Midlands (ARC EM) and the NIHR Leicester Biomedical Research Centre (BRC). ### Funding Statement UK is funded by a National Institute for Health Research (NIHR) Biomedical Research Council (BRC) / Leicester Precision Medicine Institute (LPMI) Studentship. RAE is funded by a NIHR Clinician Scientist Fellowship CS-2016-16-020. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was approved by Independent Scientific Advisory Committee for Medicines and Healthcare products Regulatory Agency database research (Protocol Number = 20_075). This study is based in part on data from the Clinical Practice Research Datalink obtained under licence from the UK Medicines and Healthcare products Regulatory Agency. I 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. Yes I 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). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The study uses data from the Clinical Practice Research Datalink (CPRD). CPRD does not allow the sharing of patient-level data.