Until unequivocal genetic predictors of CPSP are understood, the authors encourage systematic use of clinical factors for predicting and managing CPSP risk.

No externally validated presurgical risk score for chronic postsurgical pain (CPSP) is currently available. We tested the generalizability of a six-factor risk model for CPSP developed from a prospective cohort of 2929 patients in 4 surgical settings. Seventeen centers enrolled 1225 patients scheduled for inguinal hernia repair, hysterectomy (vaginal or abdominal), or thoracotomy. The 6 clinical predictors were surgical procedure, younger age, physical health (Short Form Health Survey-12), mental health (Short Form Health Survey-12), preoperative pain in the surgical field, and preoperative pain in another area. Chronic postsurgical pain was confirmed by physical examination at 4 months. The model's discrimination (c-statistic), calibration, and diagnostic accuracy (sensitivity, specificity, and positive and negative likelihood ratios) were calculated to assess geographic and temporal transportability in the full cohort and 2 subsamples (historical and new centers). The full data set after exclusions and losses included 1088 patients; 20.6% had developed CPSP at 4 months. The c-statistics (95% confidence interval) were similar in the full validation sample and the 2 subsamples: 0.69 (0.65-0.73), 0.69 (0.63-0.74), and 0.68 (0.63-0.74), respectively. Calibration was good (slope b and intercept close to 1 and 0, respectively, and nonsignificance in the Hosmer–Lemeshow goodness-of-fit test). The validated model based on 6 clinical factors reliably identifies risk for CPSP risk in about 70% of patients undergoing the surgeries studied, allowing surgeons and anesthesiologists to plan and initiate risk-reduction strategies in routine practice and researchers to screen for risk when randomizing patients in trials.