- Correspondence to Dr Sam Harper, Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, QC H3A 1A2, Canada;
- Received November 7, 2018
- Revised December 11, 2018
- Accepted December 16, 2018
- First published January 29, 2019.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.