Distribution of reviewer comments—by sponsor type
| Mean percentage of comments on a manuscript (95% CI)* | ||||
|---|---|---|---|---|
| Type of comment | Non-industry (N=89) | Industry-supported (N=78) | Industry-sponsored (N=79) | p Value |
| Importance | ||||
| 1. Research question not clinically relevant | 6.3 (2.4 to 10.2) | 6.1 (2.2 to 10.1) | 3.3 (0.3 to 6.3) | 0.372 |
| Originality | ||||
| 2. Lack of novelty | 6.1 (2.6 to 9.7) | 2.5 (0.1 to 4.9) | 8.9 (4.1 to 13.7) | 0.038 |
| Background and rationale | ||||
| 3. Incorrect background information | 20.4 (15.2 to 25.5) | 18.4 (12.2 to 24.6) | 18.8 (12.5 to 25.2) | 0.877 |
| 4. Poor justification for conducting study | 1.5 (0.0 to 3.1) | 2.8 (0.4 to 5.1) | 6.3 (2.4 to 10.1) | 0.081 |
| Methods | ||||
| 5. Poor experimental design | 69.7 (63.1 to 76.3) | 58.8 (50.2 to 67.4) | 52.9 (43.9 to 61.9) | 0.019 |
| 6. Methods inadequately reported | 60.5 (53.9 to 67.1) | 54.7 (46.7 to 62.7) | 50.8 (42.4 to 59.2) | 0.209 |
| 7. Statistical analysis methods inappropriate | 28.4 (22.3 to 34.6) | 23.5 (16.4 to 30.5) | 15.1 (10.1 to 20.2) | 0.006 |
| Results | ||||
| 8. Study outcome data incomplete | 65.9 (59.4 to 72.4) | 68.0 (59.7 to 76.4) | 58.7 (50.6 to 66.8) | 0.215 |
| 9. Flow of participants through study unclear | 7.7 (3.8 to 11.6) | 7.8 (3.3 to 12.4) | 4.6 (1.8 to 7.4) | 0.323 |
| Discussion and conclusion | ||||
| 10. Meaning results inadequately discussed | 44.2 (36.6 to 51.9) | 46.7 (38.5 to 54.9) | 56.1 (47.5 to 64.7) | 0.090 |
| 11. Study insufficiently related to literature | 15.2 (10.4 to 20.0) | 15.5 (8.3 to 22.6) | 8.7 (4.2 to 13.3) | 0.180 |
| 12. Limitations not sufficiently discussed | 17.2 (11.6 to 22.8) | 19.9 (14.7 to 25.1) | 13.8 (8.3 to 19.3) | 0.223 |
| 13. Conclusions inappropriate | 24.2 (17.7 to 30.6) | 23.0 (16.0 to 30.1) | 20.0 (13.2 to 26.8) | 0.652 |
| Abstract | ||||
| 14. Abstract does not correctly reflect paper | 16.2 (11.5 to 20.9) | 17.1 (11.8 to 22.4) | 14.4 (8.8 to 19.9) | 0.768 |
| 15. Discrepancies between the abstract and the main text | 2.0 (0.1 to 3.9) | 0.6 (0.0 to 1.6) | 1.0 (0.0 to 2.5) | 0.443 |
| References | ||||
| 16. References missing/irrelevant references used | 11.4 (7.0 to 15.8) | 12.0 (6.6 to 17.4) | 11.5 (6.1 to 16.8) | 0.985 |
| 17. Errors in reference citation | 1.5 (0.0 to 3.1) | 1.7 (0.0 to 3.5) | 4.6 (1.7 to 7.5) | 0.159 |
| Presentation | ||||
| 18. Title not representative of study | 5.0 (1.7 to 8.2) | 8.1 (3.3 to 12.8) | 1.5 (0.0 to 3.1) | 0.012 |
| 19. Poor writing | 42.8 (35.5 to 50.2) | 35.4 (27.9 to 42.9) | 34.7 (26.8 to 42.6) | 0.258 |
| 20. Inaccurate tables or figures | 37.0 (30.9 to 43.1) | 44.1 (36.5 to 51.7) | 37.2 (29.5 to 45.0) | 0.306 |
| Ethics | ||||
| 21. Ethics committee approval not clear | 2.0 (0.1 to 3.9) | 1.7 (0.0 to 3.5) | 2.1 (0.1 to 4.1) | 0.951 |
| 22. Other ethical issues related to study | 3.1 (0.0 to 6.3) | 4.1 (0.7 to 7.5) | 2.0 (0.1 to 4.0) | 0.555 |
| Trial registration, protocol, CONSORT | ||||
| 23. Registration/protocol/CONSORT missing | 2.5 (0.4 to 4.6) | 2.8 (0.4 to 5.1) | 2.6 (0.4 to 4.8) | 0.984 |
| 24. Deviations from registry or protocol | 1.4 (0.0 to 3.3) | 1.8 (0.0 to 3.8) | 1.7 (0.0 to 3.6) | 0.961 |
| COI | ||||
| 25. Bias by author COIs/contribution funder unclear | 2.5 (0.4 to 4.6) | 2.3 (0.1 to 4.4) | 3.6 (1.1 to 6.2) | 0.707 |
| 26. Systematic bias or spin in favour of sponsor | 0.0 (0.0 to 1.1) | 0.5 (0.0 to 1.8) | 1.7 (0.2 to 3.1) | 0.139 |
*The mean percentage of comments on a manuscript is controlled for the journal to which a manuscript was submitted.
COI, conflicts of interest; N, number of submitted manuscripts.