Meta-Analysis and Systematic Review of the Relationship between Hospital Volume and Outcome Following Carotid Endarterectomy

Forest plot demonstrating the volume-outcome relationship for CEA by outcome: (1A) post-operative death; (1B) post-operative stroke; (1C) combined stroke and death. Subtotals for each outcome, and an overall pooled effects estimate; (1D) are presented as odds ratios and 95% confidence intervals. Values to the left of the line of equivocal effect favour surgery at higher volume hospitals. Studies whose odds ratio is denoted by have been included on the plots to demonstrate their odds ratio only, but as no 95% confidence intervals were calculable, they were not used to calculate the pooled effect estimate.

Funnel Plots assessing publication bias. None is demonstrated in any sub-group analysis. (2A) post-operative death; (2B) post-operative stroke; (2C) combined stroke and death.