Table 2 Number of articles according to design in different medical journals. Percentages in rounded figures. §1994–2002, ¢2001, ¥August–December 2001, *November–December 2001
From: Levels of evidence in endoscopic research: a longitudinal survey
JAAGL§ | Surgical endoscopy¢ | Surgery¢ | AJOG¥ | AJOG surgical¥ | BMJ* | NEJM* | Total | |
|---|---|---|---|---|---|---|---|---|
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | ||
Systematic review | 1 (0.2) | 2 (1.2) | 0 (0) | 1 (3.7) | 0 (0) | 1 (10) | 0 (0) | 5 |
Randomized clinical trials | 48 (8.8) | 11 (6.5) | 10 (10) | 12 (44.4) | 4 (23) | 5 (50) | 14 (82) | 104 |
Non-randomized controlled trials | 65 (12) | 27 (16) | 34 (34) | 5 (18.5) | 5 (29) | 4 (40) | 2 (12) | 152 |
Case reports or case series | 432 (79) | 130 (76.5) | 55 (56) | 9 (33.3) | 8 (48) | 0 (0) | 1 (6) | 653 |
Total | 546 | 170 | 99 | 27 | 17 | 10 | 17 | 886 |