Footnotes

• AA and DB contributed equally.

• Contributors AA, DB and JW contributed to the conceptualisation of the research questions and design of the study. JW assisted in developing the search strategy and completed the database search. AA and DB wrote the first draft. DW and JW contributed to the design of the manuscript and critically revised the manuscript. All authors contributed to the interpretation of the results and commented on previous versions of the manuscript. All authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work, ensuring integrity and accuracy. AA served as the guarantor for this work and/or the conduct of the study, had access to the data, and controlled the decision to publish.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests DW is an Editorial Board Member for the BMJ Supportive and Palliative Care. All other authors declare that they have no competing interests.

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

• Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.