Table 2.

Yield of papers by stated research method (N=38).

Research method	Number of papers	References
Feasibility studies (n=12)	12	[30,31,43,45-47,49,51,53,56-58]
Program evaluation (n=8)	8	[7,15,29,33,38,40,48,50]
Randomized controlled trial (n=6)	6	[16,19,32,35,54,55]
Nonrandomized controlled trial (n=3)	3	[28,37,44]
Discussion paper (n=2)	2	[34,59]
Review (n=2)	2	[17,42]
Cost minimization analysis (n=1)	1	[14]
Descriptive (n=1)	1	[36]
Mixed methods (n=1)	1	[52]
Cohort (n=1)	1	[41]
Qualitative (n=1)	1	[39]