Chart 2. Degree of evidence of the studies according to the classification and evaluation tool.

A total of 8 points can be assigned to each study, categorized as:

1–3: high risk of bias (poor quality evidence)

4–5: moderate risk of bias (moderate quality evidence)

6–8: low risk of bias (high quality evidence)

Source: Adapted from Brusselaers et al.² (2019).