Table 2 Risk of bias assessment using Newcastle-Ottawa scale

Charles et al. [9]

***

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Waite et al. [26]

*

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Satisfactory

3

Li et al. [27]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Egbe et al. [28]

***

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Emlet et al. [29]

***

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Akena et al. [30]

*

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Satisfactory

3

Letshwenyo-Maruatona et al. [31]

*

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Satisfactory

3

Chan et al. [32]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Wu et al. [33]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Rael and Hampanda [34]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Zhang et al. [35]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Peltzer and Ramlagan [36]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Zhang et al. [37]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Srithanaviboonchai et al. [38]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Li et al. [39]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Stangl et al. [40]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Stevelink et al. [41]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Zhang et al. [42]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Rivera et al. [43]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Sayles et al. [15]

*

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Satisfactory

3

Li et al. [44]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Genberg et al. [45]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Earnshaw et al. [46]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Burke et al. [47]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5

Turan et al. [48]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Mao et al. [49]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Zhang et al. [50]

*

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Satisfactory

3

Rintamaki et al. [51]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Liu et al. [52]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Wolitski et al. [53]

**

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Good

4

Levi-Minzi and Surratt [54]

***

*

*

Newcastle-Ottawa scale adapted for cross-sectional studies

Very Good

5