58: How Much Pain Will I Have After Surgery? A Preoperative Nomogram to Predict Moderate-severe Pain Following Mastectomy

Introduction: Acute postoperative pain impacts time to opioid cessation, quality of life and is associated with chronic pain. Studies have demonstrated opioid-naïve cancer patients are at risk for developing new persistent opioid use after surgery. Effective screening tools are needed to identify patients who are at increased risk of experiencing more severe acute postoperative pain and may benefit from multimodal analgesia and early referral to pain management. The study objective was to develop a predictive nomogram to preoperatively identify patients at high risk of moderate-severe pain after mastectomy.


Methods: Demographic, psychosocial and clinical variables were retrospectively assessed in 1200 patients who underwent mastectomy from 1/2019 through 12/2020 and had pain scores available from the Recovery Tracker, a daily post-discharge questionnaire. We examined pain severity on postoperative days 1-5, categorized as none, mild, moderate, or severe, with moderate-severe pain being the outcome of interest. Multivariable logistic regression was performed to identify features associated with moderate-severe pain in a training cohort of the first 960 consecutive patients. The final model was determined using the Akaike Information Criterion. A nomogram was constructed using this model, which also included a priori-selected clinically relevant variables. Internal validation was performed in the remaining cohort of 240 patients.


Results: In the training cohort, 300 patients reported no-mild pain, 463 moderate pain, and 197 severe pain. Increased body mass index (p=0.042), preoperative Distress Thermometer score ≥4 (p=0.012), and bilateral surgery (p=0.003) predicted moderate-severe pain. The resulting nomogram accurately predicted moderate-severe pain in the validation cohort with an AUC of 0.734 (Figure).


Conclusions:

This nomogram incorporates eight preoperative variables to provide a risk estimate of moderate-severe pain following mastectomy. This can be used for preoperative risk stratification, and to identify patients who may benefit from individually tailored perioperative pain management and early postoperative interventions to treat pain and assist with opioid tapering.