D espite a 10-year survival rate of 83%, 1,2 between 25% and 60% of surviving patients who have undergone surgery for breast cancer experience persistent postsurgical pain, [3][4][5][6][7][8][9] which is associated with reduced quality of life and functional impairment. [10][11][12][13] Systematic reviews summarizing proposed risk factors for persistent pain after breast cancer surgery -including demographic, intraoperative and postoperative factors -have had several limitations, including outdated searches, inadequate attention to risk-of-bias assessment, lack of statistical pooling of measures of association and failure to evaluate the quality of evidence.5,10-14 We conducted a systematic review and meta-analysis of observational studies to identify risk factors for persistent pain after breast cancer surgery, addressing the limitations of previous reviews. MethodsWe completed our systematic review in accordance with the MOOSE statement 15 and registered our protocol with PROSPERO (registration CRD42014013338). Background: Persistent pain after breast cancer surgery affects up to 60% of patients. Early identification of those at higher risk could help inform optimal management. We conducted a systematic review and meta-analysis of observational studies to explore factors associated with persistent pain among women who have undergone surgery for breast cancer. Predictors of persistent pain after breast cancer surgery: a systematic review and meta-analysis of observational studies