Fig. 4From: Association between chronic obstructive pulmonary disease and serum lipid levels: a meta-analysisBegg’s funnel plot analysis and Egger’s test to detect publication bias. a Begg’s funnel plot analysis and Egger’s test for HDL. b Begg’s funnel plot analysis and Egger’s test for LDL. c Begg’s funnel plot analysis and Egger’s test for TC. d Begg’s funnel plot analysis and Egger’s test for TGBack to article page