Table 1.

Assessment of quality of general population studies and studies toward specific Populations at risk

Aspect	Score	Description
Age	0	Not determined
	0	Determined with clear bias; not representative to general/targeted population
	1	Determined with no clear bias; can be considered representative
Gender	0	Not determined
	0	Determined with clear bias
	1	Determined with no clear bias; can be considered representative
Coverage	1	Single centre/local
	2	Multi-centre/local
	3	Multi-centre/national
Sample sizea	0	Less than 150 participants
	1	More than 150 and less than 1000 participants
	2	More than 1000 participants

^aThresholds were set based on authors opinion solely