Table 3 Univariable and multivariable logistic regression derived odds ratios (OR) and 95% confidence intervals (CI) for the effect of year of publication, journal, continent of corresponding author, ethical approval, involvement of statistician, trial registration, significance of results, conflict of interest, funding, impact factor and number of authors on the likelihood of SR inclusion
Predictor variables | Category | Univariable analysis | Multivariable analysis | ||
|---|---|---|---|---|---|
OR (95%CI) | p-value | OR (95%CI) | p-value | ||
Journal | AJODO | Reference | |||
ANGLE | 1.50 (0.59, 3.78) | 0.390 | |||
EJO | 1.27 (0.54, 3.01) | 0.587 | |||
OCR | 1.20 (0.32, 4.47) | 0.786 | |||
AOJ | Not estimable | – | |||
JOO | Dropped (exactly same % with AJODO) | – | |||
JO | 1.00 (0.17, 5.88) | 1.00 | |||
Continent of corresponding author | Europe | Reference | |||
Americas | 1.45 (0.50, 4.18) | 0.491 | 1.22 (0.41, 3.61) | 0.72 | |
Asia or other | 0.41 (0.21, 0.78) | 0.007 | 0.36 (0.18, 0.71) | 0.003 | |
Ethical approval | No approval or exempt from approval | Reference | |||
Ethical approval obtained | 1.69 (0.54, 5.27) | 0.367 | |||
Involvement of statistician | Not reported | Reference | |||
Reported | 1.08 (0.66, 1.76) | 0.755 | |||
Trial registration | No | Reference | |||
Yes | 1.41 (0.75, 2.67) | 0.284 | |||
Significance of results | Not significant | Reference | |||
Significant | 1.00 (0.55, 1.83) | 1.000 | |||
Conflict of interest | Conflicts exist and declared | Reference | |||
No conflicts to declare | 1.09 (0.56, 2.04) | 0.782 | |||
Not clearly declared | 1.79 (0.20, 15.92) | 0.600 | |||
Funding | Industry funded and declared | Reference | |||
No industry sponsorship/funding to declare | 0.57 (0.29, 1.11) | 0.100 | |||
Not clearly declared | 0.89 (0.33, 2.38) | 0.820 | |||
Year of publication | Per unit | 1.07 (0.96, 1.18) | 0.220 | 1.09 (0.98, 1.22) | 0.11 |
Impact factor | Per unit | 1.52 (0.76, 3.06) | 0.237 | ||
Number of authors | Per unit | 1.07 (0.93, 1.22) | 0.339 | ||