Table 2.
Risk of bias of the studies, according to the Newcastle-Ottawa Scale adapted for cross-sectional studies
| Selection (maximum 5 stars) | Comparability (maximum 2 stars) | Outcome (maximum 5 stars) | Total score (maximum 10) | |
|---|---|---|---|---|
| Flores-Mir et al. 2018 [13] | 4 | 1 | 3 | 8 |
Newcastle-Ottawa Quality Assessment Scale (adapted for cross sectional studies)
Selection (maximum 5 stars):
1. Representativeness of the sample:
a)Truly representative of the average in the target population. * (all subjects or random sampling)
b)Somewhat representative of the average in the target population. * (nonrandom sampling)
c)Selected group of users.
d)No description of the sampling strategy.
2. Sample size:
a) Justified and satisfactory. *
b) Not justified.
3. Non-respondents:
a) Comparability between respondents and non-respondents characteristics is established, and the response rate is satisfactory. *
b) The response rate is unsatisfactory, or the comparability between respondents and non-respondents is unsatisfactory.
c) No description of the response rate or the characteristics of the responders and the non-responders.
4. Ascertainment of the exposure (risk factor):
a) Validated measurement tool. **
b) Non-validated measurement tool, but the tool is available or described.*
c) No description of the measurement tool.
Comparability (maximum 2 stars):
1. The subjects in different outcome groups are comparable, based on the study design or analysis. Confounding factors are controlled.
a) The study controls for the most important factor (select one). *
b) The study control for any additional factor. *
Outcome (maximum 3 stars):
1. Assessment of the outcome:
a) Independent blind assessment. **
b) Record linkage. **
c) Self-report. *
d) No description.
2. Statistical test:
a) The statistical test used to analyze the data is clearly described and appropriate, and the measurement of the association is presented, including confidence intervals and the probability level (p value). *
b) The statistical test is not appropriate, not described or incomplete