Weekday vs weekend endoscopy: Is there a true difference in patient outcomes? A meta-analysis

Table 2 Quality assessment of the studies based upon the effective public health practice project scale

Ref.	Selection bias	Study design	Confounders	Blinding	Data collection method	Withdrawals and dropouts	Overall assessment
Youn et al[3]	Moderate	Moderate	Weak	N/A	Strong	N/A	Moderate
de Groot et al[4]	Strong	STRONG	Moderate	N/A	Strong	Strong	Strong
Byun et al[9]	Weak	Moderate	Weak	N/A	Strong	N/A	Weak
Jairath et al[11]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Button et al[22]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Dorn et al[18]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Shaheen et al[1]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Myers et al[10]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Ananthakrishnan et al[2]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Bell et al[14]	Strong	Moderate	Weak	N/A	Strong	N/A	Moderate
Haas et al[8]	Weak	Moderate	Weak	N/A	Strong	N/A	Weak

N/A: Not applicable.