Contribution of authorship:

All authors made significant contribution to the manuscript. KO was responsible for study design and conception. TS, JB, JS and KO wrote the manuscript, which was developed from an MRes thesis submitted to the University of Huddersfield by TS; supervised by JB and JS.
JS and TS conducted the statistical analysis. JB, JS and KO provided critical feedback.
All authors approved the final manuscript for submission.