Table V.

An overview of the quality assessment of studies using SIGN, Drummond and Cochrane criteria

Authors	Overall			Quality
	High	Moderate	Low
Chun et al., 2016	81.5%	6.8%	11.6%	High
Chowers et al., 2015	80.3%	8.1%	11.6%	High
Bessesen et al., 2013	76.7%	3.5%	19.7%	Moderate
Hassan et al., 2007	45.4%	26.7%	27.9%	Low
Montecalvo et al., 2001	63.5%	11.6%	24.8%	Moderate
van Rijen et al., 2009	70.4%	12.9%	16.7%	Moderate
Wassenberg et al., 2011	67.0%	11.5%	21.5%	Moderate