Table 1. Characteristics of studies included in the meta-analysis.* .
| ID | Study | Year | Ethnic group | Sample size (Frequency of H allele, %) | OR (95%CI) for H versus R allele | Hardy-Weinberg equilibrium of genotype of control | |
| Case | Control | ||||||
| 1 | Cotterchio et al. [11] | 2008 | mainly Caucasian | 834(31.35) | 1249(32.78) | 0.936(0.820–1.070) | 0.078 |
| 2 | Lilla et al. [12] | 2007 | Caucasian | 504(35.61) | 603(34.91) | 1.031(0.866–1.229) | 0.178 |
| 3 | Chen et al. [13] | 2006 | Asian | 140(8.93) | 343(6.27) | 1.466(0.877–2.451) | 0.749 |
| 4 | Gaustadnes et al. [14] | 2006 | Caucasian | 230(37.39) | 540(32.69) | 1.230(0.980–1.544) | NA |
| 5 | Sun et al. [15] | 2005 | Caucasian | 109(48.17) | 666(37.31) | 1.561(1.171–2.082) | 0.478 |
| 6 | Landi et al. [16] | 2005 | Caucasian | 361(26.59) | 320(26.88) | 0.986(0.775–1.254) | 0.011 |
| 7 | Sterjev et al. [17] | 2005 | Caucasian | 100(27.00) | 200(36.75) | 0.637(0.439–0.924) | 0.034 |
| 8 | Pereira et al. [18] | 2005 | Brazilian | 42(36.90) | 100(33.00) | 1.188(0.697–2.022) | 0.960 |
| 9 | Sachse et al. [19] | 2002 | Caucasian | 490(34.39) | 593(32.12) | 1.107(0.925–1.325) | 0.734 |
| 10 | Nowell et al. [20] | 2002 | Caucasian | 130(37.31) | 301(42.36) | 0.801(0.601–1.092) | 0.815 |
| 11 | Wong et al. [21] | 2002 | Caucasian | 383(30.94) | 402(32.09) | 0.948(0.766–1.173) | 0.082 |
| 12 | Bamber et al. [22] | 2001 | Caucasian | 226(34.51) | 293(32.08) | 1.116(0.860–1.447) | 0.621 |
*OR: odds ratio; CI: confidence interval; NA: not available.