Funding for this research was provided by:
National Institutes of Health (L40 DA042434, R25DA037756, U01DA038886)
Michael Smith Foundation for Health Research
Canadian Institutes of Health Research
Canadian Research Chairs Program
Received: 10 July 2017
Accepted: 28 November 2017
First Online: 7 December 2017
Ethics approval and consent to participate
: The University of British Columbia/Providence Health Care Research Ethics Board approved the study and consent to participate was obtained from each participant.
: Not applicable.
: The authors declare that they have no competing interests.
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