Fig. 3From: Prevalence and risk factors of postoperative delirium after spinal surgery: a meta-analysisFunnel plot of postoperative delirium after spinal surgery (Egger’s test, p = 0.797 and Begg’s test, p = 0.008). a Adjusted funnel plot of postoperative delirium after spinal surgery after adding two “missing” studies from the “trim and fill” analysis (b)Back to article page