Table 2 Characteristics of included studies

Year of publication

 2004 to 2008

 2009 to 2014

 2015 to 2019

 2020 to 2024

16

9

21

16

(25.8)

(14.5)

(33.9)

(25.8)

Location of study

 United States

 The Netherlands

 United Kingdom

 Germany

 Australia

 Canada

 Italy

 Other

15

10

8

7

4

4

3

11

(24.2)

(16.1)

(12.9)

(11.3)

(6.5)

(6.5)

(4.8)

(17.7)

Study design

Quantitative

 Cross-sectional

 Longitudinal

 Randomized trial

 Quasi-experimental

 Cohort

21

3

3

1

1

(33.9)

(4.8)

(4.8)

(1.6)

(1.6)

Qualitative

 Design not specified

 Grounded theory

 Interpretive description

23

3

1

(37.1)

(4.8)

(1.6)

Mixed methods

3

(4.8)

Program evaluation

3

(4.8)

Type of data collected

Single data source

 Surveys or questionnaires

 Interview transcripts

 Focus group transcripts and/or fieldnotes

24

18

7

(38.7)

(29.0)

(11.3)

Multiple data sources

 Interview/focus group transcripts and surveys/questionnaires

6

(9.7)

 Interview and focus group transcripts and fieldnotes

3

(4.8)

 Participant observation and surveys/questionnaires

3

(4.8)

 Interview transcripts, surveys/questionnaires, and administrative data

1

(1.6)

Study participants

Total number of participants across studies

116,770

Median number of participants per study (interquartile range)

149 (795.5)

Range of participants per study

 Minimum

 Maximum

6

40,677