[Optimized assessment of the outcome in patients with radicular back pain of the lumbar spine. The modified NASS questionnaire].

BACKGROUND: The purpose of the study was to present a reliable instrument with easy application to assess the outcome and improvement of therapy in patients with radicular symptoms of the lumbar spine.

METHODS: Data from patients who underwent microdiscectomy because of lumbar radicular symptoms were collected and analyzed and interviews were performed using the well-known North American Spine Society (NASS) lumbar spine questionnaire (17 items) before and after the intervention. In addition patient data including comorbidities were collected. By calculating effect size (ES) and standardized response mean (SRM) for each item of the questionnaire, the questions with the highest change before and after the intervention could be selected.

RESULTS: A total of 139 patients undergoing microdiscectomy for lumbar radicular symptoms due to a disc herniation were included in the analysis. Concerning the three dimensions pain, neurological symptoms and impairment of activities in daily life, the questions with best predictive value (high ES and SRM) were selected. According to their clinical relevance eight questions of the NASS questionnaire were finally selected for the short form.

CONCLUSION: This short, significant and easy to use questionnaire is in our opinion a useful instrument to assess the course of patients with radicular back pain and especially to measure and monitor the outcome of therapeutic interventions, in addition to conventional clinical diagnostics and examinations. This novel instrument could be a useful tool for improving quality assurance in conventional and interventional pain management of these patients.