Assessing Neuropathic Pain and Depression

The study was approved by the Ethics Committees of the Universities of Bochum and Würzburg. After providing informed consent, the patients were required to complete four questionnaires: the NPSI-G, the German version of the NPS (NPS-D), the graded chronic pain scale (GCPS, [12 (link)]), and the German version of the Center for Epidemiologic Studies Depression Scale (CES-D) [13 ]. Patients diagnosed with neuropathic pain were instructed to complete a 2nd NPSI-G as well as the patient global impression of change (PGIC) scale [14 (link)] 24 hours later. The entire set of questionnaires was repeated at 4 weeks. Since most of these patients were inpatients, their 24 hour questionnaire was readily distributed and collected. Outpatients with neuropathic pain were given both the 24 hour and 4 week questionnaires with dates for completion clearly marked and prepaid postal envelopes addressed to the investigators. Patients who did not return the questionnaires at the specified time intervals received telephone reminders. During the 4-week period, patients underwent medical treatment as required. Patients with headache (mostly outpatients) or osteoarthritis pain (mostly inpatients) received all of the above questionnaires only once and were instructed to complete their questionnaires while at the hospital.
Depressive symptoms were assessed using the CES-D questionnaire. Scores above 23 points were considered indicative of depressive states. Pain intensities were graded using the 11-point numerical scales (0 - 10) of the GCPS.