- Association of quality of randomized-controlled trials (RCTs) with journal impact factor (2018-2019) and open access publication (n=406).
| Variable | 1990-2005 | 2006-2018 | ||||
|---|---|---|---|---|---|---|
| Open access publication | JIF R (P-value) | Open access publication | JIF R (P-value) | |||
| Yes n (%) | No n (%) | Yes n (%) | No n (%) | |||
| Random sequence generation | ||||||
| Unclear risk | 9 (69.2) | 43 (50.0) | 0.141 (0.166) | 31 (31.3) | 58 (30.9) | 0.145 (0.014)* |
| Low risk | 2 (15.4) | 26 (30.2) | 55 (55.6) | 107 (56.9) | ||
| High risk | 2 (15.4) | 17 (19.8) | 13 (13.1) | 23 (12.2) | ||
| P-value | 0.453 | 0.952 | ||||
| Allocation concealment | ||||||
| Unclear risk | 9 (69.2) | 60 (69.8) | −0.003 (0.980) | 46 (46.5) | 95 (50.5) | 0.096 (0.107) |
| Low risk | 1 (7.7) | 9 (10.5) | 32 (32.3) | 57 (30.3) | ||
| High risk | 3 (23.1) | 17 (19.8) | 21 (21.2) | 36 (19.2) | ||
| P-value | 1.000 | 0.810 | ||||
| Blinding of participants and personnel | ||||||
| Unclear risk | 4 (30.8) | 18 (20.9) | 0.079 (0.440) | 21 (21.2) | 45 (23.9) | 0.073 (0.217) |
| Low risk | 1 (7.7) | 29 (33.7) | 37 (37.4) | 61 (32.5) | ||
| High risk | 8 (61.5) | 39 (45.4) | 41 (41.4) | 82 (43.6) | ||
| P-value | 0.162 | 0.699 | ||||
| Overall risk of bias | ||||||
| Unclear risk | 2 (15.4) | 37 (43.0) | 0.057 (0.577) | 47 (47.5) | 91 (48.4) | 0.095 (0.110) |
| High risk | 11 (84.6) | 49 (57.0) | 52 (52.5) | 97 (51.6) | ||
| P-value | 0.071 | 0.902 | ||||
*Statistically significant (p<0.05), JIF: Journal impact factor, R: Spearman’s rho (spearman correlation coefficient)