Laparoscopic vs open approach to resection of hepatocellular carcinoma in patients with known cirrhosis: Systematic review and meta-analysis

Table 2 Risk of bias using the Newcastle-Ottawa Scale

Study	Selection				Comparability	Outcome
	Representativeness of exposed cohort	Selection of non-exposed cohort	Exposure	Outcome of interest not present at start	Comparability of laparoscopic vs open	Assessment of outcome	Follow-up	Adequacy of follow-up/missing data	Score
Kanazawa et al[18]	Truly representative	Same	Surgical records	Yes	No restrictions, not matched	Record linkage	5 yr	Unclear	7
Cheung et al[23]	Truly representative	Same	Surgical records	Yes	No restrictions, matched	Record linkage	5 yr	None	8
Truant et al[33]	Truly representative	Same	Surgical records	Yes	Restricted to subcapsular tumours located in the anterior or lateral segments II-VI, matched	Record linkage	5 yr	Unclear	7
Belli et al[32]	Truly representative	Same	Surgical records	Yes	Restricted in exophytic or subcapsular tumours, no matching	Record linkage	3 yr	Unclear	7