POSTER SESSION IIIMENTAL HEALTH—Patient-Reported Outcomes StudiesPSY28 HEALTH CARE AND NON-HEALTH CARE RESOURCES UTILIZATION AND RELATED COSTS IN SUBJECTS WITH REFRACTORY PAIN ASSOCIATED TO LOW BACK PAIN: A POST-HOC ANALYSIS OF THE EFFECT OF PREGABALIN IN A 12-WEEK PROSPECTIVE STUDY UNDER ROUTINE MEDICAL PRACTICE CONDITIONS