The effect of preoperative HbA1c on chronic postsurgical pain in diabetic patients undergoing video-assisted thoracic surgery - A retrospective cohort study

•The incidence of chronic postsurgical pain (CPSP) in patients with diabetes mellitus was higher than the general population.•Patients with preoperative HbA1c ≥ 6.5% had a higher incidence of CPSP at 3 months compared to patients with HbA1c < 6.5%.•Preoperative HbA1c ≥ 6.5%, postoperative acute pain degree, incision infection and chemotherapy are risk factors for CPSP.