Quality assessment of the studies included in meta-analysis.

a“+” means the study specifying the location where NG isolates were collected; “−” stands for this information missing from the study.
b“+” means the study specifying isolates collection period; “−” stands for this information missing from the study.
c“+” means the study describing the population from whom NG isolates were obtained; “−” stands for this information missing from the study.
d“+” means the study describing the method of identifying NG isolates; “−” stands for this information missing from the study.
e“+” means the study indicating the number of tested NG isolates; “−” stands for this information missing from the study.
f“+” means the study including at least 100 tested NG isolates; “−” stands for the study failing to do it.
g“+” means the study utilizing control strains recommended by WHO in determining MICs with agar dilution method; “−” stands for the study failing to do it.