“…All the meta-analysed clinical trials were published as full-text papers [23-27, 29, 30, 41-47]. Four studies had a Jadad score ⩾3 [23,24,42,45,47], and 10 studies had a Jadad score ⩾1 and <3 [25-27, 29, 30, 41, 43, 44, 46, 47]. The length of treatment ranged from 1 day to 12 weeks.…”