“…Out of the 33 studies, one was triple-blind
[24], 24 were double-blind
[2,4-6,8,11,12,14,17,18],
[20,25-37], three were single-blind
[19,38,39], and in five studies the blinding was unclear
[3,40-44]. Additionally, 21 studies had a Jadad score greater than three
[2,4-6,11,12,14,17-19,24-27,31],
[33-38] indicating they were of high quality.…”