Footnotes

• Contributors BPCS conceived and designed the work, prepared the initial draft and approved the final version. AT and CS revised critically the work, provided substantial intellectual content and approved the final version.

• Funding This work was funded by Australian National Health and Medical Research Council. AT and CS receive salary funding.

• Competing interests None declared.

• Patient consent Not required.

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