Table 2.
Risk of bias assessment of observational studies
| Authors | Item 1 | Item 2 | Item 3 | Item 4 | Item 5 | Item 6 | Item 7 | Item 8 | Item 9 | Total |
|---|---|---|---|---|---|---|---|---|---|---|
| Abelman et al. 2020 [25] | N | Y | N | Y | Y | Y | Y | N | N | 5 |
| Castro-Sanchez et al. 2018 [35] | N | Y | N | Y | Y | Y | Y | N | N | 5 |
| Cutler et al. 2016 [36] | N | Y | N | Y | Y | N | Y | N | N | 4 |
| Dominick et al. 2015 [18] | Y | Y | N | Y | Y | Y | Y | Y | Y | 8 |
| Franca et al. [37] | N | N | N | N | Y | Y | Y | N | N | 3 |
| Guth et al. 2016 [38] | N | Y | N | Y | Y | Y | Y | N | N | 5 |
| Hadnott et al. 2019 [23] | Y | Y | Y | Y | Y | Y | Y | N | N | 7 |
| Johansen et al. 2017 [39] | N | Y | N | Y | Y | Y | Y | N | N | 5 |
| Knight et al. 2014 [40] | N | N | N | N | N | Y | Y | N | N | 2 |
| Lakhdissi et al. 2017 [41] | N | N | N | N | N | Y | Y | N | N | 2 |
| Madrigal et al. 2019 [42] | N | N | N | Y | Y | Y | Y | N | N | 4 |
| Maslow et al. 2014 [43] | N | Y | N | Y | Y | Y | Y | Y | Y | 7 |
| Massarotti et al. 2021 [34] | N | Y | N | N | Y | Y | Y | N | N | 4 |
| McLean et al. 2014 [44] | N | Y | N | Y | N | N | N | Y | N | 3 |
| Mody et al. 2019 [26] | Y | Y | N | Y | Y | Y | Y | N | N | 6 |
| Patel et al. 2015 [45] | N | N | N | Y | Y | Y | N | N | N | 3 |
| Patel et al. 2009 [33] | N | N | N | Y | Y | Y | N | N | N | 3 |
| Quinn et al. 2014 [46] | Y | Y | Y | Y | Y | Y | Y | N | N | 7 |
Item 1: Was the sample representative of the target population?
Item 2: Were the study participants recruited in an appropriate way?
Item 3: Was the sample size adequate?
Item 4: Were the study subjects and the setting described in detail?
Item 5: Was the data analysis conducted with sufficient coverage of the identified sample?
Item 6: Were objective, standard criteria used for the measurement of the condition?
Item 7: Was the condition measured reliably?
Item 8: Was there an appropriate statistical analysis?
Item 9: Are all important confounding factors/subgroups identified and accounted?