Fig. 2

Co-occurrence of data collection methods. a Number and percentage of all articles (n = 227) reporting the use of document analysis, focus groups, and/or site visits. Forty-four articles (19%) reported no use of any of these methods. b Number and percentage of all articles (n = 227) reporting the use of focus groups, observations and/or surveys. Fifty-five articles (24%) reported no use of any of these methods. c Number and percentage of all articles (n = 227) reporting the use of surveys, focus groups, observations and/or site visits. Twenty-two articles (10%) reported no use of any of these methods. d Number and percentage of all articles (n = 227) reporting the use of surveys, focus groups, observations and/or interviews. Four articles (2%) reported no use of any of these methods