Competing interests MA declares speaking fees and research grants from Grunenthal, Menarini and Horizon. Patient and public involvementPatients and/or the public were not involved in the design, conduct, reporting or dissemination plans of this research. Patient consent for publication Not required.Provenance and peer review Not commissioned; internally peer reviewed. This article is made freely available for use in accordance with BMJ's website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained.

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