Funding for this research was provided by:
EU FP7 IMI JU (115317)
Received: 14 March 2018
Accepted: 23 July 2018
First Online: 4 September 2018
Ethics approval and consent to participate
: Not applicable for this study (for the DIRECT study itself, appropriate ethics approval was received in each of the recruiting countries).
: Not applicable.
: The authors declare that they have no competing interests.
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