Article info

Download PDFPDF



  1. Correspondence to Antonia Johnston; production.bmjopen{at}
View Full Text


Johnston A

Publication history

  • Received February 2, 2017
  • Revised March 1, 2017
  • Accepted March 2, 2017
  • First published April 22, 2017.
Online issue publication 
April 22, 2017

Request permissions

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.