PD-L1 rs2890658 Polymorphism Increases Risk for Non-Small-Cell Lung Cancer in Northern China Population Based on Experimental Data and Meta-Analysis

Table 4

Quality assessment of the four case–control studies according to the Newcastle-Ottawa scale.

Literature	Selection of enrolled study subjects	Between-group comparability	Exposure outcomes and factors	Total
Moura et al.	2	3	3	8
Loganathan et al.	3	3	3	9
Wu et al.	2	3	3	8
Tseng et al.	2	3	3	8
Average	2.3	3.0	3.0	8.3