#15 | RCT |
#16 | Controlled clinical trial |
#17 | Clinical trial |
#18 | #1 or #2 or #3 or #4 or #5 |
#19 | #6 or #7 or #8 or #9 or #10 |
#20 | #11 or #12 or #13 or #14 or #15 or #16 or #17 |
#21 | #18 and #19 and #20 |