Estimating minimally important differences (MID) for the worst pain rating of the brief pain inventory (BPI)-short form (SF).

Abstract

6112 Background: The BPI-SF is a widely used patient-reported outcome measure for assessing pain and has become the standard for use in clinical and research studies. The rating of worst pain is often selected as the primary outcome of interest; however, there are no published data available on its MID, particularly as a change score. The data presented in this analysis can help to enhance interpretation of the assessment. Methods: Patients with advanced breast cancer who enrolled in a randomized, double-blind, phase 3 study comparing denosumab vs. zoledronic acid in the treatment of bone metastases completed the BPI-SF, FACT-B, and EQ-5D questionnaires at baseline, week 5, and every 4 weeks thereafter until the end of the study. After assessing the correlation between change in the BPI worst pain rating with several potential anchors using the interval from baseline to week 25, we computed both anchor-based and distribution-based MID estimates for the BPI worst pain rating in both treatment arms combined...