MOESM8 of The efficacy and safety of continuous versus single-injection popliteal sciatic nerve block in outpatient foot and ankle surgery: a systematic review and meta-analysis MaHsuan-Hsiao ChouTe-Feng TsaiShang-Wen ChenCheng-Fong WuPo-Kuei ChenWei-Ming 2019 Additional file 8: Figure S8. Funnel plot of VAS score at 72 h.