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A prospective study of 12-week respiratory outcomes in COVID-19-related hospitalisations
  1. Aditi S Shah1,
  2. Alyson W Wong1,
  3. Cameron J Hague2,
  4. Darra T Murphy2,
  5. James C Johnston1,
  6. Christopher J Ryerson1,
  7. Christopher Carlsten1
  1. 1 Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
  2. 2 Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
  1. Correspondence to Dr Christopher J Ryerson, Department of Medicine, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada; chris.ryerson{at}


The long-term respiratory morbidity of COVID-19 remains unclear. We describe the clinical, radiological and pulmonary function abnormalities that persist in previously hospitalised patients assessed 12 weeks after COVID-19 symptom onset, and identify clinical predictors of respiratory outcomes. At least one pulmonary function variable was abnormal in 58% of patients and 88% had abnormal imaging on chest CT. There was strong association between days on oxygen supplementation during the acute phase of COVID-19 and both DLCO-% (diffusion capacity of the lung for carbon monoxide) predicted and total CT score. These findings highlight the need to develop treatment strategies and the importance of long-term respiratory follow-up after hospitalisation for COVID-19.

  • interstitial fibrosis
  • lung physiology
  • respiratory infection

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  • ASS and AWW are joint first authors.

  • JCJ, CJR and CC are joint senior authors.

  • ASS and AWW contributed equally.

  • JCJ, CJR and CC contributed equally.

  • Contributors AS and AW are co-first authors and contributed equally to this work. JJ, CC and CJR are co-senior authors and contributed equally to this work. AS, AW, CC, CJR and JJ contributed to study design, data analysis, data interpretation and writing of the manuscript. CH and DM provided chest CT interpretations and contributed to data interpretation and writing of the manuscript. All authors read and approved the final version of the manuscript. All authors had full access to the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

  • Funding This work was funded by the Michael Smith Foundation for Health Research, the TB Vets charitable foundation, the Vancouver Coastal Health Research Institute and the University of British Columbia’s Strategic Investment Fund.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval All patients provided written informed consent (UBC Clinical Research Ethics Board #H20-01239).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement The supplementary index provides Table S1 and Figure S1. Relevant raw data available on reasonable request.

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