Fig. 2From: The analgesic efficacy compared ultrasound-guided continuous transverse abdominis plane block with epidural analgesia following abdominal surgery: a systematic review and meta-analysis of randomized controlled trialsCochrane collaboration risk of bias summary: evaluation of bias risk items for each included study. Green circle = low risk of bias; red circle = highrisk of bias; yellow circle = unclear risk of biasBack to article page