METHODS: Pooled data from 5 clinical trials evaluating effectiveness of the lidocaine patch 5% for osteoarthritis (OA) knee pain and low back pain (LBP) were analyzed to assess patient satisfaction. IRB approvals were obtained for all studies. Of the patients treated (N = 463) with the lidocaine patch 5%, 411 were included in the analysis based on having a score on the Patient Global Assessment of Treatment Satisfaction (PGATS) scale and having participated in at least 1 of the following measures: Brief Pain Inventory (BPI) average pain intensity, BPI pain relief, any Neuropathic Pain Scale (NPS) score, or adverse events (AEs) score. BPI sleep interference ratings and mental health and physical function subscales were also included. A set of hierarchical logistic regression models with relevant covariates entered first followed by hypothesized predictor variables was used to evaluate their contribution in predicting treatment responders defined as those with PGATS responses of “satisfied” or “very satisfied.”

RESULTS: Analyses were performed separately for each disease group. For LBP patients, improvement from baseline to last observed measurement in BPI average pain (P = 0.0016) and pain relief (P = 0.0295) correlated with being a responder. For OA patients, reduced average pain (P = 0.0262), greater pain relief (P = 0.0229), and improved physical function (P = 0.0153) correlated with being a responder, as did improvements in deep (P = 0.0009), hot (P = 0.0054), and unpleasant (P = 0.0253) pain.

CONCLUSIONS: Understanding how clinical endpoints correlate with patient satisfaction may help in future analgesic trials by identifying endpoints that are important to patients, minimizing use of outcome measures that fail to provide any incremental benefit in the evaluation of treatment response.