Ethics approval and consent to participate

This study was conducted in accordance with the requirements of the study protocol which was approved by Veritas Independent Review Board and also in accordance with: the ethical principles that have their origin in the Declaration of Helsinki; the International Conference on Harmonisation, E6 Good Clinical Practice: Consolidated Guideline; guidelines for good pharmacoepidemiology (GPP); and all applicable laws and regulations, including, without limitation, data privacy laws, clinical trial disclosure laws, and regulations, to protect the rights, safety, privacy, and well-being of study participants.

Informed consent

Patient consent was waived by Veritas Independent Review Board as this study was retrospective, information abstracted for the study was already collected as part of routine clinical care and contained within the patient’s health record. No additional contact with participants for information was needed. All information was kept strictly confidential.

Consent for publication

This study involves a retrospective chart review and has been conducted in compliance with relevant ethical guidelines and regulations. As this research involves analysis of previously collected data, consent was waived by the Veritas Independent Review Board and individual patient consent for publication was not required.

Competing interests

AA reports conference travel support and/or honoraria from BioCryst, Covis Pharma, CSL-Behring, GSK, and Takeda and clinical trial support from Astria, BioCryst, Ionis Pharmaceuticals, Kalvista, Octapharma, Pharvaris, and Takeda. JNB reports medical advisory boards for Biocryst, CSL Behring and Takeda. DG reports advisory boards and consultancy from Alexion, BioCryst, CSL Behring, Medison, Pfizer, Sanofi, Sobi, and Takeda; research funding from Takeda. CK reports advisory boards for Takeda, CSL and Biocryst. AK reports advisory boards and consultancy from BioCryst, Canadian Blood Services, CSL Behring and Takeda; Speaker’s honoraria from Biocryst, CSL Behring and Takeda; research funding from CSL Behring, Takeda). SW reports consulting fees from GSK, Novartis, CSL Behring, Pfizer Canada, Sanofi Canada, AstraZeneca, Takeda, ALK Abello, Teva, Medexus, MiravoHealth, Mylan, Bausch Lomb, AbbVie, Avir Pharma, Leo Pharma,Valeo; research grants from Pfizer Canada, Alk Abello, Aimmune; is current President of Canadian Allergy, Asthma and Immunology Foundation; is currently on the Board of Directors for Asthma Canada. MN and JW were employees of Pentavere Research Group at the time of the study. AW and AEZ were employees of Takeda Canada Inc at the time of the study. SB reports advisory boards and consultancy from ALK, Astria, BioCryst, Canadian Blood Services, CSL Behring, Ionis, Kalvista, Pharming, Pharvaris, Takeda and WSIB; speaker’s honoraria from Biocryst, CSL Behring, Novartis and Takeda; research funding from CIHR, CIRN, CSL and Takeda.