Table 2 Characteristics of randomized controlled trials
Characteristics of RCTs | n = 50 | 2003–2008 (6 y) n = 27 | 2009–2014 (6 y) n = 23 | |||
|---|---|---|---|---|---|---|
Total n (%) | Drug 20 (74) | Non drug 7 (26) | Drug 20 (87) | Non drug 3 (13) | ||
Experimental design | ||||||
Parallel | 43 (86) | 19 | 5 | 17 | 2 | 0.697 |
Cross-over | 7 (14) | 1 | 2 | 3 | 1 | |
Level of blind | ||||||
Double blind | 29 (58) | 13 | 1 | 14 | 1 | 0.052 |
Single blind | 2 (4) | 1 | 0 | 0 | 1 | |
Open labeled | 19 (38) | 6 | 6 | 6 | 1 | |
Allocation concealment | ||||||
Inadequate | 4 (8) | 2 | 0 | 2 | 0 | 0.055 |
Unclear | 20 (40) | 7 | 6 | 5 | 2 | |
Adequate | 26 (52) | 11 | 1 | 13 | 1 | |
Jadad class | ||||||
Median [interquartile range] | 4 [3–5] | 1 [1–2] | 5 [2.5–5] | 3 [1–5] | 0.758 | |
Low quality <3 | 15 (30) | 3 | 6 | 5 | 1 | |
High quality ≥3 | 35 (70) | 17 | 1 | 15 | 2 | |
Jadad class in sensitivity analysis | ||||||
Median [interquartile range] | 5 [3–5] | 3 [1–5] | 5 [4–5] | 5 [5–5] | 0.650 | |
Low quality <3 | 5 (15) | 2 | 1 | 2 | 0 | |
High quality ≥3 | 28 (25) | 13 | 1 | 12 | 2 | |