NON-INTERVENTIONAL OBSERVATIONAL STUDY FOR THE EVALUATION OF TOLERABILITY AND EFFICACY OF THE WHO-STEP III OPIOIDS OXYCODONE/NALOXONE PR AND TAPENTADOL PR UNDER DAILY LIFE CONDITIONS IN PATIENTS SUFFERING FROM NEUROPATHIC (LOW) BACK PAIN. (OXYNTA) | HMA-EMA Catalogues of real-world data sources and studies