Footnotes

• Handling editor Jamie Scott Frankis

• Twitter @EricPFChow, @drtrphillips, @kitfairley

• Contributors EPFC and CKF conceived and designed the study. EPFC performed data analyses and wrote the first draft of the manuscript. CL and JT performed data cleaning. KM assisted with project management. EPFC, CL, JT, TRP, KM and CKF were involved in data interpretation. All authors were involved in revising the manuscript for important intellectual content and approved the final version. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.

• Funding EPFC is supported by an Australian National Health and Medical Research Council (NHMRC) Emerging Leadership Investigator Grant (GNT1172873). CKF is supported by an Australian NHMRC Leadership Investigator Grant (GNT1172900).

• Competing interests EPFC is an editorial fellow of Sexually Transmitted Infections.

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