Footnotes

• Contributors All authors participated in the design of the analyses. PM, RL and DvdH performed the analyses. All authors participated in drafting the paper and all authors approved the final manuscript.

• Funding PM was supported by the Fundação para a Ciência e a Tecnologia (FCT) grant SFRH/BD/62329/2009.

• Competing interests None.

• Ethics approval Ethics committee approval was secured for the ASSERT trial. This study is an investigator-preformed subanalysis of the ASSERT cohort.

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