Quality of life assessment from participant-reported interference of pain on quality of life from weeks 1 to 24 for the intention-to-treat population. For the Brief Pain Inventory-Short Form, patients recorded a score of 0 (does not interfere) to 10 (completely interferes) for the areas of general activity, mood, walking ability, relations, sleep, and enjoyment. For participants with responses of greater than 50% for the aforementioned areas, a total pain interference score, consisting of a mean of individual area scores, was calculated. SE = standard error.