Statistical methods and reporting in the evaluated journals
| Respiratory journals | NEJM+Lancet | Selected medical journals | All articles | p-value of Chi-squared test | |
| Total articles n | 160 | 320 | 360 | 840 | |
| Statistical methods described | 100 (62.5) | 219 (68.4) | 221 (61.4) | 540 (64.3) | 0.140 |
| Reference to statistical literature | 38 (23.8) | 144 (45.0) | 104 (28.9) | 286 (34.0) | <0.001 |
| Statistical software reported | 126 (78.8) | 191 (59.7) | 215 (59.7) | 532 (63.3) | <0.001 |
| Comparing groups | 111 (69.4) | 221 (69.1) | 199 (55.3) | 531 (63.2) | <0.001 |
| Repeated measurements | 18 (11.3) | 35 (10.9) | 36 (10.0) | 89 (10.6) | 0.884 |
| Correlation coefficient methods | 38 (23.8) | 25 (7.8) | 75 (20.8) | 138 (16.4) | <0.001 |
| Regression models | 96 (60.0) | 205 (64.1) | 165 (45.8) | 466 (55.5) | <0.001 |
| Other multivariable methods | 9 (5.6) | 13 (4.1) | 35 (9.7) | 57 (6.8) | 0.010 |
| Intra-cluster correlation methods | 24 (15.0) | 58 (18.1) | 57 (15.8) | 139 (16.5) | 0.614 |
| Measures of agreement | 27 (16.9) | 31 (9.7) | 69 (19.2) | 127 (15.1) | 0.002 |
| Bayesian methods | 1 (0.6) | 5 (1.6) | 4 (1.1) | 10 (1.2) | 0.712 |
| ANN or machine learning | 0 | 2 (0.6) | 0 | 2 (0.2) | 0.181 |
Data are presented as n (%), unless stated otherwise. NEJM: New England Journal of Medicine; ANN: artificial neural networks.