Study Random selection
in the population 		Definition of inclusion
and exclusion criteria 		Report of
losses to follow-up 		Validated
measurements 		Statistical
analysis 		Risk of
bias
Marchetti et al. [4] No No - Yes Yes High
Seeberger et al. [24] No No - Yes Yes High
Yao et al. [25] No No No Yes Yes High
Moralis et al. [26] No No - Yes Yes High

- = not relevant.