Table 1.

Quality assessment according to the Newcastle-Ottawa quality assessment scale.

		References
		Bhrany et al. [20]	de Pablo et al. [21]	Mardini et al. [22]
Item
Selection	Representativeness of the exposed cohort.
	Selection of nonexposed cohort.
	Ascertainment of exposure.
	Demonstration that outcome of interest was not present at start of the study.
Comparability	Study controls for other variables.
Outcome	Assessment of outcome.
	Degree of FU was long enough for outcomes to occur.
	Adequacy of FU of cohorts.
SCORE (/9)		6	8	6

, no agreement; , agreement.