Which pain intensity scale from the Brief Pain Inventory correlates most highly with functional interference scores in patients experiencing taxane-induced arthralgia and myalgia?

PURPOSE: The purpose of this study was to assess which pain intensity dimension scale (worst, least, average, or current pain) from the Brief Pain Inventory (BPI) correlates most highly with functional interference scores in patients experiencing taxane-induced arthralgia and myalgia. METHODS: Breast cancer patients scheduled to receive docetaxel, paclitaxel, or albumin-bound paclitaxel (nab-paclitaxel) were enrolled in the study. Patients completed an initial baseline questionnaire and subsequently filled out a diary based on the BPI on days 1-7, 14, and 21 for three consecutive treatment cycles. Pain scores for worst, least, average, and current pain intensity dimensions as well as pain interference scores were recorded in the diaries and questionnaires using the BPI. Worst, least, average, and current pain scores were correlated with functional pain interference scores using Spearman's rank correlation coefficients. A general linear mixed model of each functional interference measure was performed over time for cycles 1-3 with each pain intensity dimension scale. RESULTS: Among worst, average, least, and current joint pain dimensions, average joint pain scores correlated best with all BPI interference responses while average muscle pain scores correlated best with all BPI interference responses except for sleeping probability and normal work. CONCLUSION: We recommend the BPI scale measuring average pain for future studies evaluating pain scores in patients experiencing taxane-induced arthralgia and myalgia.