Study by | Year | Number of patients | Hazard ratio | 95% CI |
Kwan et al. [78] | 1997 - 2000 | 1945 | 0.67 | 0.39, 1.13 |
Ahern et al. [21] | 1996 - 2003 | 18,769 | 0.7 | 0.57, 0.86 |
Chae et al. [20] | 1999 - 2005 | 703 | 0.4 | 0.24, 0.67 |
Nickels et al. [79] | 2001 - 2005 | 3024 | 0.83 | 0.54, 1.24 |
Boudreau et al. [80] | 1990 - 2008 | 4216 | 0.82 | 0.62, 1.08 |