Establishing the patient acceptable symptom state for patient-reported pain outcomes 6 months after breast cancer surgery.

INTRODUCTION

The patient-acceptable symptom state (PASS) is a threshold score on patient-reported outcome measures beyond which patients consider their symptoms unacceptable (PASS negative). The PASS may guide the interpretation of outcomes associated with persistent pain after breast cancer surgery (PPBCS).

OBJECTIVES

This study aimed to identify PASS cut-off values for the numerical rating scale (NRS) on the brief pain inventory (BPI) items for pain at 6 months after breast cancer surgery and describe functional and psychological outcomes associated with an unacceptable (PASS-negative) pain state.

METHODS

This prospective cohort study included patients undergoing primary breast cancer surgery. Patients were assessed preoperatively and postoperatively at 2 weeks and 6 months using validated questionnaires. Patient-acceptable symptom state was evaluated at 6 months after surgery. Patients were classified into PASS-positive (acceptable pain state) or PASS-negative groups using a pain-specific anchor question. Patient-acceptable symptom state thresholds for the BPI items were determined using the Youden index on a receiver operating characteristic curve.

RESULTS

Of the 140 included patients, 13.6% reported a PASS-negative state at 6 months after surgery. Compared to PASS-positive patients, PASS-negative patients reported greater pain severity, pain interference, psychological distress, upper limb disability, and neuropathic pain (all < 0.008). Numerical rating scale patient-acceptable symptom state cut-off values for the BPI items were 1.5 (worst pain), 0.5 (average pain), and 0.8 (pain interference).

CONCLUSION

The NRS scores for the BPI worst pain >1.5, average pain >0.5, and pain interference >0.8 delineated patients with "unacceptable" PPBCS. These values may define clinically meaningful PPBCS and offer pain cut-off values for research.