Table 1 Systematic review search strategy

Terms for randomised controlled trials:

1. random:.mp.

2. trial.ab, kw, ti.

Cluster design-related terms:

3. “cluster*”.ab, kw, ti.

4. “group*”.ab, kw, ti.

5. “communit*”.ab, kw, ti.

6. 3 OR 4 OR 5

School MeSH term:

7. exp Schools/

Highest precision:

8. 1 AND 2 AND 6 AND 7

9. 8 limited to English language