Table 1. Quality assessment scores for the selected studies based on the quality of genetic association studies (Q-Genie).
| Studies | Items | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | Score | |
| Bleecker et al,2012 [16] | 5 | 5 | Na | 5 | 4 | 5 | 6 | 5 | 6 | 5 | 5 | 51 |
| Ishii et al, 2014 [25] | 5 | 4 | 3 | 6 | 3 | 3 | 3 | 5 | 4 | 4 | 5 | 45 |
| Ishii et al, 2011 [21] | 6 | 4 | 5 | 4 | 2 | 5 | 2 | 3 | 4 | 4 | 5 | 44 |
| Lin et al, 2011 [22] | 5 | 6 | 3 | 5 | 2 | 3 | 3 | 5 | 2 | 4 | 4 | 42 |
| Mandal et al, 2015 [14] | 6 | 6 | Na | 3 | 2 | 6 | 1 | 4 | 3 | 5 | 6 | 42 |
| Pillai et al, 2010 [15] | 4 | 6 | Na | 5 | 5 | 4 | 5 | 6 | 5 | 4 | 6 | 50 |
| Quint et al,2011 [23] | 5 | 4 | 5 | 5 | 2 | 3 | 6 | 3 | 5 | 4 | 5 | 47 |
| Quint et al, 2012 [24] | 4 | 5 | 3 | 4 | 5 | 4 | 2 | 6 | 3 | 4 | 4 | 44 |
| Takabatake et al, 2006 [19] | 7 | 6 | Na | 6 | 5 | 5 | 3 | 6 | 6 | 5 | 6 | 55 |
| Umeda et al, 2008 [17] | 5 | 4 | Na | 4 | 4 | 5 | 2 | 4 | 4 | 3 | 4 | 39 |
| Yang et al, 2003 [20] | 6 | 6 | 4 | 5 | 5 | 5 | 3 | 5 | 5 | 5 | 6 | 55 |
| Zhang et al,2015[26] | 5 | 5 | 5 | 4 | 4 | 5 | 4 | 6 | 4 | 4 | 4 | 50 |
| Zhang et al,2015 [18] | 5 | 5 | Na | 4 | 4 | 4 | 5 | 6 | 4 | 4 | 5 | 46 |
1- rationale for study; 2- selection and definition of outcome of interest; 3- selection and comparability of comparison group (if applicable); 4- technical classification of the exposure; 5- non-technical classification of the exposure; 6 other sources of bias; 7- sample size and power; 8- a priori planning of analysis; 9- statistical methods and control for confounding; 10- testing of assumptions and inferences for genetic analysis; 11- appropriateness of inferences drawn from results. All items have a maximum score of 7.
Na–not applicable