Table 4.

Database types in the included studies (n=45).

Database type	Studies
Medical knowledge database	[10,11,13,15-17,20,22-24,26-28,31-33,36-42,47,48,50-53]
User information database	[11,13,18,21,25,39,40,45,46,50,53]
Conversation scripts	[11,12,14,15,19]
Not mentioned	[21,29,30,34,35,43,44,49,54]