JF contributed to project conception and design, design of survey instrument, data acquisition and manuscript revision.
MH contributed to the conception of study, design of survey, overseeing and contributing to the writing of this paper.
AW contributed to the conception of study, design of survey, input into qualitative schedule, and contribution to the content of the paper and feedback on the final draft.
RL conception of study, design of survey, data analysis, data interpretation, contribute to writing 'Introduction' and 'Discussion' and feedback to the final draft.
LW and MP contributed to the conception of the study, survey design, and interpreting the data.
KF made substantial contributions to the conception of the survey and took active part in interpreting the results and revising the manuscript.
SY, MC, CD and RSF all participated in conception of the study and survey design.
MP contributed to project conception and design, revision of survey instrument and manuscript revision/critical appraisal.
DH contributed to the conception and design, adaptation of survey tools, field data collection, data processing and analysis, and the drafting and revisions of the paper.
CD contributed to the conception of the study and design of the survey, distributed the survey, analyzed and interpreted the data, drafted the manuscript, and approved the final manuscript as submitted.
KW contributed to the conception of the four surveys and in the writing up of the manuscript.
