Table 1 Overview of study’s stages, including purpose, approach and time-line

1. Establishment of advisory group and development of methodological approach

To guide the methodological approach

Members from the advisory group discussed methodology and criteria for prioritisation via Skype and email.

Three 60–90 min Skype discussions (October 2016–February 2017);

30-min face-to-face meeting during consultation on cash (4 November 2016); email feedback (October 2016–June 2017).

2. Consultation on research questions

(a) Online survey

(b) Face-to-face group session

To identify key research questions on this topic

(a) Sample of global stakeholders was invited to complete the survey.

(b) Attendees of a consultation session on cash were asked to list research questions.

(a) 10-min survey was open for 3 weeks (28 March to 19 April 2017)

(b) 1 h face-to-face session on 4 November 2016

3. Clarification and prioritisation of research questions and categories

To refine and rank research questions and categories

Members of the advisory group were asked to prioritise research questions based on four criteria. Content analysis was used to develop and rank research categories.

About 1.5 h during 1 month (11 May to 11 June 2017)

4. Triangulation of findings with past evidence reviews

To check whether identified categories (a) have not yet been addressed by primary research and (b) whether existing literature reviews recommend research on similar or differing topics.

Published and unpublished literature reviews were identified (through recommendations by authors, searching the CALP library, and checking reference lists of selected papers) and discussed in relation to identified research categories.

October–November 2017