Table 3.
NOS quality assessment table. Each study was awarded one star per item within the selection and exposure categories. A maximum of two stars could be awarded for comparability. The score is the sum of the awarded stars and ranges from zero to nine.
| Ref. | First Author | Selection | Comparability | Exposure | Score | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Is the Case Definition Adequate? | Representativeness of the Cases | Selection of Controls | Definition of Controls | Based on the Design or Analysis |
Ascertainment of Exposure | Same Method of Ascertainment for Cases and Controls | Non-Response Rate | |||
| [14] | Abdollahzadeh P; 2017 | * | * | * | * | * | * | * | 5/9 | |
| [19] | Badawi H; 2008 | * | * | * | * | * | * | * | * | 7/9 |
| [20] | Barghi MR; 2005 | * | * | * | * | * | * | * | * | 6/9 |
| [32] | Gould VE; 2010 | * | * | * | * | * | * | * | * | 6/9 |
| [37] | Kim SH; 2014 | * | * | * | * | * | * | * | * | 6/9 |
| [42] | Mete UK; 2018 | * | * | * | * | * | * | * | 5/9 | |
| [47] | Sarier M; 2019 | * | * | * | * | * | * | * | 5/9 | |
| [49] | Shaker OG; 2013 | * | * | * | * | * | * | * | 5/9 | |
| [50] | Shigehara K; 2011 | * | * | * | * | * | * | * | 5/9 | |
| [53] | Steinestel J; 2013 | * | * | * | * | * | * | * | 5/9 | |
| [54] | Tekin MI; 1999 | * | * | * | * | * | 5/9 | |||
“*”: Each study was awarded one star per item. The score is the sum of the awarded stars, ranged from 0 to 9 (high-quality, >7 stars; medium-quality, 4–6 stars; poor-quality, <4 stars).