Brien, Sarah B
Lewith, George T
Thomas, Mike
Article History
Received: 11 December 2015
Revised: 2 June 2016
Accepted: 17 June 2016
First Online: 15 September 2016
Competing interests
: MT is an Associate Editor of npj Primary Care Respiratory Medicine, but was not involved in the editorial review of, nor the decision to publish, this article. The authors declare no conflict of interest.