Chronic postsurgical pain (CPSP) is defined by pain intensity and pain-related functional interference. This study included measures of function in a composite score of patient-reported outcomes (PROs) to investigate the incidence of CPSP. Registry data were analyzed for PROs one day and 12 months postoperatively. Based on pain intensity and pain-related interference with function, patients were allocated to the groups "CPSPF" (at least moderate pain with interference), "Mixed" (milder symptoms) and "No CPSPF". The incidence of CPSPF was compared to CPSP rates referring to published data. Variables associated with the PRO-12 score (composite PROs at 12 months; NRS 0-10) were analyzed by linear regression analysis. Of 2319 patients, 8.6%, 32.5% and 58.9% were allocated to the groups CPSPF, Mixed and No CPSPF. Exclusion of patients whose pain scores did not increase compared to the preoperative status, resulted in a 3.3% incidence. Of the patients without pre-existing pain, 4.1% had CPSPF. Previously published pain cut-offs of NRS >0, ≥3 or ≥4, used to define CPSP, produced rates of 37.5%, 9.7% and 5.7%. Pre-existing chronic pain, pre-operative opioid medication and type of surgery were associated with the PRO-12 score (all p<0.05). Opioid doses and PROs 24 hours postoperatively improved the fit of the regression model. A more comprehensive assessment of pain and interference resulted in lower CPSP rates than previously reported. Although inclusion of CPSP in the ICD-11 is a welcome step, evaluation of pain characteristics would be helpful in differentiation between CPSPF and continuation of pre-existing chronic pain.
