Qualitative	Cross Sectional	Case Control	Cohort	RCT	Systematic Review
Diagnosis				*	**	***
Therapy				*	**	***
Prognosis				***
Screening			*	*	**	***
Views/Beliefs/Perceptions	***
Prevalence/Hypo. Gen.	***	***

Table 1:The number of stars (asterix) means the more appropriate the study design for that study question.