Influential factors | Estimated regression coefficients (95%CI) | |||
---|---|---|---|---|
Multivariable | P-value | Sensitivity analysis | P-value | |
No. of authors | ||||
≤ 4 | Reference | Reference | ||
5 ~ 6 | 0.78 (0.35, 1.20) | < 0.001 | 0.73 (0.28, 1.18) | 0.002 |
7~ 8 | 0.86 (0.37, 1.36) | 0.001 | 0.68 (0.18, 1.19) | 0.008 |
> 8 | 1.15 (0.61, 1.70) | < 0.001 | 0.99 (0.48, 1.49) | < 0.001 |
Year of publication | ||||
2011 | Reference | Reference | ||
2012 | 0.39 (−0.41, 1.20) | 0.338 | 0.77 (− 0.05, 1.58) | 0.066 |
2013 | 1.23 (0.28, 2.18) | 0.011 | 1.12 (0.18, 2.05) | 0.020 |
2014 | 0.93 (0.13, 1.74) | 0.023 | 1.08 (0.20, 1.96) | 0.016 |
2015 | 1.35 (0.58, 2.11) | 0.001 | 1.39 (0.54, 2.25) | 0.001 |
2016 | 2.01 (1.28, 2.75) | < 0.001 | 2.19 (1.38, 3.00) | < 0.001 |
2017 (up to July-31) | 2.39 (1.60, 3.18) | < 0.001 | 2.56 (1.62, 3.52) | < 0.001 |
Linear trend test | 0.38 (0.28, 0.47) | < 0.001 | 0.38 (0.27, 0.50) | < 0.001 |
Use of reporting guidance | ||||
No | Reference | Reference | ||
Yes | 0.98 (0.63, 1.32) | < 0.001 | 0.99 (0.61, 1.37) | < 0.001 |
Region | ||||
European | Reference | Reference | ||
Asia Pacific | −0.21 (− 0.66, 0.23) | 0.348 | − 0.28 (− 0.74, 0.17) | 0.224 |
America | − 0.18 (−1.31, 0.95) | 0.752 | − 0.54 (−1.61, 0.53) | 0.320 |
Methodologist involved | ||||
No | Reference | Reference | ||
Yes | 0.86 (0.42, 1.32) | < 0.001 | 0.78 (0.36, 1.19) | < 0.001 |