Systematic review comparing endoscopic, percutaneous and surgical pancreatic pseudocyst drainage

Table 4 Methodological summary of the risk of bias of the included non-randomized comparative studies

	Selection	Comparability	Outcomes
	(++++)	(++)	(++++)
Melman et al[9]	++		++
Varadarajulu et al[12]	++	+	+++
Kahaleh et al[13]	++		+++
Morton et al[14]	++	++	+++
Heider et al[15]	++	+	++
Adams et al[16]	++		++
Lang et al[17]	++		++

Quality assessment was according to the Newcastle-Ottawa scale for non-randomized trials. +: Higher quality of the studies.