Table 1.
Relation between characteristics of journal and reporting of trial registration number (TRN)
| Journal characteristics | Papers with TRN/total No of papers (%) | P value* | Binary logistic regression | |
|---|---|---|---|---|
| P value | Odds ratio (95% CI) | |||
| Overall | 7473/10500 (71.2) | |||
| Journal impact factor: | <0.001 | |||
| Top quarter (≥4.9) | 2011/2261 (88.9) | <0.001 | <0.001 | 3.66 (3.07 to 4.35) |
| Third quarter (3.2-4.9) | 1742/2250 (77.4) | <0.001 | 2.18 (1.88 to 2.52) | |
| Second quarter (2.2-3.2) | 1550/2250 (68.9) | <0.001 | 1.4 (1.22 to 1.6) | |
| Bottom quarter (<2.2) | 1246/2253 (55.3) | 0.001 | 0.80 (0.70 to 0.92) | |
| Unidentified† | - | - | - | Reference |
| Journal type: | <0.001 | |||
| ICMJE member | 721/755 (95.5) | <0.001 | <0.001 | 5.76 (4.02 to 8.25) |
| Follows ICMJE recommendations | 2351/3072 (76.5) | <0.001 | 1.38 (1.25 to 1.53) | |
| Neither | 4401/6673 (66) | - | Reference | |
*
Pearson’s χ2 test.
†
Excluding 1486 papers as journal impact factor could not be identified.