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. “communit*”.ab, kw, ti

 5. group*adj2 random*.ab, kw, ti

 6. 3 OR 4 OR 5

School terms:

 7. exp Schools/

 8. School*.ab, kw, ti

 9. 7 OR 8

Final search stages:

 10. 1 AND 2 AND 6 AND 9

 11. 10 limited to English language