Table 2 Characteristics of studies reporting continuous outcomes (n = 73)
Variable | Median [25th, 75th percentile]/ n (%) |
|---|---|
Sample size of patients | 89 [29, 222] |
Study duration (weeks) | 13 [12, 17] |
Median improvement from baseline in the placebo arm | 1.8 [1.0, 3.0] |
Age | 41.0 [38.6, 42.3] |
% Female | 85.9% [81.6%, 88.8%] |
Placebo route | |
 Oral | 35 (48.0%) |
 Injection | 33 (45.2%) |
 Intravenous | 5 (6.85%) |
Year of publication | |
 1996 to 2004 | 13 (17.8%) |
 2005 to 2009 | 17 (23.3%) |
 2010 to 2014 | 7 (9.6%) |
 2015 to 2019 | 24 (32.9%) |
 2020 to 2021 | 12 (16.4%) |
Outcome measure | |
 Monthly migraine days | 33 (45.2%) |
 Migraine headache days per month | 8 (1.0%) |
 Attacks per month | 15 (21%) |
 Episodes per month | 3 (4.1%) |
 Migraine days | 7 (9.6%) |
 Attack frequency | 5 (6.9%) |
 Headache days per month | 0 (0.0%) |
 Headache days | 2 (2.8%) |
Jadad or Oxford scoring system | |
 High | 71 (97.3%) |
 Low | 2 (2.7%) |
Cochrane risk of bias | |
 High | 11 (15.1%) |
 Some concerns | 14 (19.2%) |
 Low | 48 (65.8%) |
Use of migraine prophylaxis medication | |
 Yes | 27 (37.0%) |
 No | 40 (57.8%) |
 Not reported | 6 (8.2) |
Acute medication use permitted | |
 Yes | 69 (94.5%) |
 Not reported | 4 (5.5%) |