[ . . . ] In conclusion, evidence based methods, including the funnel plot, should be evidence based. If treatment decisions are made on the basis of misleading methodological tests, the costs to patients and society could be high. Decisions guided by the easy assurance of a symmetrical funnel plot may overlook serious bias. Equally, it may be misleading to discredit and abandon valid evidence simply because of an asymmetrical funnel plot. The prevention of publication bias is much more desirable than any diagnostic or corrective analysis.