Table 3.
Risk of bias assessment using Newcastle–Ottawa scale
| Study | Selection (***) | Comparability (*) | Exposure/outcome (*) | Method of assessment | Quality assessment | Quality assessment score |
|---|---|---|---|---|---|---|
| Levi-Minzi and Surratt [71] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Emlet et al. [67] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Turan et al. [77] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Li et al. [72] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Zhang et al. [82] | * | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Satisfactory | 3 |
| Zhang et al. [80] | *** | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 | |
| Courtenay–Quirk et al. [66] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Zeng et al. [79] | * | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Satisfactory | 3 |
| Li et al. [106] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Lambert et al. [65] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Felker-Kantor et al. [69] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Ferlatte et al. [70] | ** | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Satisfactory | 3 | |
| Fekete et al. [68] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Galvan et al. [18] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Akena et al. [63] | ** | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Satisfactory | 3 | |
| Lee et al. [30] | *** | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 | |
| Pearson et al. [74] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Burke et al. [64] | * | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Satisfactory | 3 |
| Rael and Hampanda [76] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Turan et al. [78] | ** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Good | 4 |
| Peltzer and Ramlagan [75] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |
| Zhang et al. [81] | *** | * | * | Newcastle–Ottawa scale adapted for cross-sectional studies | Very good | 5 |