Distribution of study design, sample size and main outcome by the evaluated journals
| AJRCCM | ERJ | Chest | Thorax | NEJM+Lancet | Selected medical journals | All articles | |
| Total articles n | 40 | 40 | 40 | 40 | 320 | 360 | 840 |
| Study design | |||||||
| 14 (35.0) | 10 (25.0) | 10 (25.0) | 12 (30.0) | 43 (13.4) | 107 (29.7) | 196 (23.3) |
| 14 (35.0) | 10 (25.0) | 11 (27.5) | 10 (25.0) | 49 (15.3) | 62 (17.2) | 156 (18.6) |
| 4 (10.0) | 7 (17.5) | 3 (7.5) | 3 (7.5) | 7 (2.2) | 18 (5.0) | 42 (5.0) |
| 3 (7.5) | 7 (17.5) | 6 (15.0) | 11 (27.5) | 173 (54.1) | 60 (16.7) | 260 (30.9) |
| 4 (10.0) | 5 (12.5) | 1 (2.5) | 2 (5.0) | 7 (2.2) | 69 (19.2) | 88 (10.5) |
| 0 | 1 (2.5) | 5 (12.5) | 1 (2.5) | 15 (4.7) | 18 (5.0) | 40 (4.8) |
| 1 (2.5) | 0 | 4 (10.0) | 1 (2.5) | 26 (8.1) | 26 (7.2) | 58 (6.9) |
| Sample size | |||||||
| 4 (10.0) | 8 (20.0) | 7 (17.5) | 5 (12.5) | 34 (10.6) | 65 (18.1) | 120 (14.3) |
| 9 (22.5) | 9 (22.5) | 7 (17.5) | 9 (22.5) | 27 (8.4) | 62 (17.2) | 123 (14.6) |
| 12 (30.0) | 7 (17.5) | 9 (22.5) | 7 (17.5) | 39 (12.2) | 45 (12.5) | 117 (13.9) |
| 15 (37.5) | 16 (40.0) | 17 (42.5) | 19 (47.5) | 206 (64.4) | 145 (40.3) | 423 (50.4) |
| 0 | 0 | 0 | 0 | 14 (4.4) | 43 (11.9) | 57 (6.8) |
| Statistical significance of primary outcome | |||||||
| 6 (15.0) | 4 (10.0) | 7 (17.5) | 5 (12.5) | 72 (22.5) | 41 (11.4) | 135 (16.1) |
| 30 (75.0) | 28 (70.0) | 21 (52.5) | 27 (67.5) | 162 (50.6) | 218 (60.6) | 486 (57.8) |
| 4 (10.0) | 8 (20.0) | 12 (30.0) | 8 (20.0) | 86 (26.9) | 101 (28.0) | 219 (26.1) |
Data are presented as number of articles (%), unless stated otherwise. AJRCCM: American Journal of Respiratory and Critical Care Medicine; ERJ: European Respiratory Journal; NEJM: New England Journal of Medicine.