Data collection will record parameters of patients undergoing surgery at four different times: preoperative assessment (60 to 1 day before the scheduled procedure); evaluation of the perioperative period; and postoperative period (from the third month following surgery).

The outcome variable is the presence of CPSP assessed 3 months after surgery and defined as an average pain intensity of at least 3 on the NRS scale (11-point one-dimensional pain scale) in the last three days, and pain localized to the surgical field (or in the lesion area) projected into the innervation territory of a nerve located in this area or referred to a dermatome.

Separate prediction models will be developed using data derived from surveys conducted at the relevant time points for the development of the risk index.

Presence of CPSP assessed 3 months after surgery and defined as an average pain intensity of at least 3 points on the NRS scale (one-dimensional pain scale - from 0 to 10 points) in the last three days and pain localized to the surgical field (or in the lesion area) projected into the innervation territory of a nerve located in this area, or referred to a dermatome.

• Age

  • 18-35
  • 36-55
  • ≥55

• Sex

  • Female
  • Male

• BMI

  • ≤18.5 - 24.9
  • 25 - 29.9
  • ≥30

• Alcohol or substances of abuse (Y/N) (specify the substance)

• Previous experience of pain NRS ≥5 for 7 days (Y/N)

• Presence of chronic pathologies (Y/N) (if yes, provide the list of medications)

• Pharmacological treatments including supplements or nutraceuticals (continuous in the last 3 months) (Y/N) (if yes, provide the list of drugs)

• Chronic pain (NRS ≥3 for ≥3 months) (Y/N)

• Neuropathic pain (Y/N) (assessment using Douleur Neuropathique en 4 questions DN-4 questionnaire)

• Pain catastrophizing (Y/N) (assessment via Pain Catastrophizing Scale PCS questionnaire)

• Anxiety (Y/N) (assessment using General Anxiety Disorder-7 GAD-7 questionnaire)

• Depression (Y/N) (assessment using Beck Depression Inventory BDI-II questionnaire)

• Presence of pain in the last three days (NRS ≥3 mean pain intensity in the 24 hours) (Y/N)

• Primary version of the risk index, made up of items derived from a systematic bibliographic search (compilation of the item pool).
• Authors will analyze the associations between each of these indices and the probability of CPSP 3 months after surgery (dichotomous variable), evaluated using logistic regression models.
• Items that were found to be significant in the bivariate analyses will then be analyzed multivariately (logistic regression models).
• Authors will safeguard the results of the multivariate analyses by calculating the area under the ROC curve of the model, and then, the cut-off score for a high risk of developing CPSP will be identified with an optimal compromise between sensitivity and specificity.
• The items that will generate significant predictive factors in the logistic regression analyses will be collected into an index. For each value of this index, the Authors will calculate the proportion of patients who reported CPSP at 3 months after surgery.