The influence of the grade of chronicity on the outcome of multidisciplinary therapy for chronic low back pain.

STUDY DESIGN: Prospective longitudinal clinical study.

OBJECTIVE: The objective of the study was to analyze the outcome of different stages of chronicity in patients with chronic low back pain treated with a multidisciplinary therapy.

SUMMARY OF BACKGROUND DATA: Results of studies comparing different grades of chronicity in therapy for chronic low back pain have not been published so far.

METHODS: A total of 387 patients with chronic low back pain for 3 months or longer and a corresponding sick leave for longer than 6 weeks underwent a 3-week standardized multidisciplinary therapy. At baseline (T0), patients were assigned into 3 groups of chronicity grades according to the classification of von Korff et al (Group A, Grades I and II; Group B, Grade III; Group C, Grade IV) and were prospectively followed. At the the 6-month follow-up (T1), 5 different therapy outcomes were analyzed and compared in the 3 groups: back-to-work status, generic health status (SF-36), pain intensity (visual analogue scale), functional capacity (Hannover back capacity score), and satisfaction with the therapy.

RESULTS: At T0, patients in Group C had a higher pain level, a longer history of pain, and more general and more psychosomatic comorbidities than patients with lower levels of chronicity. All 3 treatment groups improved significantly in all outcome criteria between T0 and T1. In the total group, the back-to-work rate was 67.4%. At the final follow-up, there were significantly better results in terms of functional capacity and pain level in patients with lower grades of chronicity but mostly due also to worse initial baseline values. Back-to-work rate, satisfaction with therapy, and the Mental Component Summary of the SF-36 did not show a significant difference at T1 between the groups analyzed.

CONCLUSION: According to the results of this study, patients with chronic low back pain also derive significant benefit from a multidisciplinary treatment strategy in higher stages of chronicity. Therefore, therapy should not be limited to the patients in lower stages of chronicity.