Conflict of interest: A.I. Hernandez Cordero has nothing to disclose. Conflict of interest: C.X. Yang has nothing to disclose. Conflict of interest: S. Milne has nothing to disclose. Conflict of interest: X. Li has nothing to disclose. Conflict of interest: Z. Hollander reports funding from Genome Canada, Genome British Columbia, Genome Quebec, the Canadian Institutes of Health Research, PROOF Centre of Excellence, St. Paul's Hospital Foundation and Providence Health Care for the Rapid Transition Program (RTP) cohort included in the manuscript. Conflict of interest: V. Chen reports funding from Genome Canada, Genome British Columbia, Genome Quebec, the Canadian Institutes of Health Research, PROOF Centre of Excellence, St. Paul's Hospital Foundation and Providence Health Care for the Rapid Transition Program (RTP) cohort included in the manuscript. Conflict of interest: R. Ng reports funding from Genome Canada, Genome British Columbia, Genome Quebec, the Canadian Institutes of Health Research, PROOF Centre of Excellence, St. Paul's Hospital Foundation and Providence Health Care for the Rapid Transition Program (RTP) cohort included in the manuscript. Conflict of interest: S.J. Tebbutt has nothing to disclose. Conflict of interest: J.M. Leung reports research grant funding (to institution) from Canadian Institutes of Health Research, Michael Smith Foundation for Health Research, BC Lung Association and Genome BC, outside the scope of the current manuscript. Conflict of interest: D.D. Sin declares grants from AstraZeneca for an investigator-initiated randomised controlled trial in COPD; consulting fees from Novaira for sitting on an advisory board for COPD; and honoraria for speaking engagements from AstraZeneca, Boehringer Ingelheim and Grifols, all in the 36 months prior to manuscript submission.