Table 1.

Results of the methodological quality appraisal (Effective Public Health Practice Project) of the included studies

Component	Thubisi	Bickell	Lomas
Selection bias avoided	Strong	Strong	Strong
Allocation bias avoided	Moderate	Strong	Moderate
Confounders avoided	Strong	Strong	Strong
Blinding (but not considered when calculating global quality score)	Weak	Weak	Weak
Data collection methods	Weak	Strong	Strong
Withdrawals & Drop-outs	Strong	Strong	Strong
Analysis: Intention to treat	Strong	Strong	Weak
Intervention integrity: % of participants that received allocated intervention	Strong	Strong	Strong
Global quality score	Moderate	Strong	Moderate
Include study	Yes	Yes	Yes