Table 4 OQAQ component score results for Kropmans et al 1999[27]

1. Were the Search methods used to find evidence on the primary question(s) stated?

2. Was the search for evidence reasonably comprehensive?

3. Were the criteria used for deciding which studies to include in the overview reported?

4. Was bias in the selection of studies avoided?

5. Were the criteria used for assessing the validity of the included studies reported?

6. Was the validity of all the studies referred to in the text assessed using appropriate criteria?

7. Were the methods used to combine the findings of the relevant (to reach a conclusion) reported?

8. Were the findings of the relevant studies combined appropriately relative to the primary question of the overview?

9. Were the conclusions made by the author(s) supported by the data and/or analysis reported in the overview?