An observational study on trajectories and outcomes of chronic low back pain patients referred from a spine surgery division for chiropractic treatment

Background: A close collaboration between surgeons and non-surgical spine experts is crucial for optimal care of low back pain (LBP) patients. The affiliation of a chiropractic teaching clinic to a university hospital with a large spine division in Zurich, Switzerland, enables such collaboration. The aim of this study was to describe the trajectories and outcomes of patients with chronic LBP referred from the spine surgery division to the chiropractic teaching clinic. Methods: The patients filled in an 11-point numeric rating scale (NRS) for pain intensity and the Bournemouth Questionnaire (BQ) (bio-psycho-social measure) at baseline and after 1 week, 1, 3, 6 and 12 months. Additionally, the Patient's Global Impression of Change (PGIC) scale was recorded at all time points apart from baseline. The courses of NRS and BQ were analyzed using linear mixed model analysis and repeated measures ANOVA. The proportion of patients reporting clinically relevant overall improvement (PGIC) was calculated and the underlying factors were determined using logistic regression analyses. Results: Between June 2014 and October 2016, 67 participants (31 male, mean age = 46.8 +/- 17.6 years) were recruited, of whom 46 had suffered from LBP for > 1 year, the rest for > 3 months, but < 1 year. At baseline, mean NRS was 5.43 (SD 2.37) and mean BQ was 39.80 (SD 15.16) points. NRS significantly decreased [F(5, 106.77) = 3.15, p = 0.011] to 4.05 (SD 2.88) after 12 months. A significant reduction was not observed before 6 months after treatment start (p = 0.04). BQ significantly diminished [F(5, 106.47) = 6.55, p < 0.001] to 29.00 (SD 17.96) after 12 months and showed a significant reduction within the first month (p < 0.01). The proportion of patients reporting overall improvement significantly increased from 23% after 1 week to 47% after 1 month (p = 0.004), when it stabilized [56% after 3 and 6 months, 44% after 12 months]. Reduction in bio-psycho-social impairment (BQ) was of higher importance for overall improvement than pain reduction. Conclusions: Chiropractic treatment is a valuable conservative treatment modality associated with clinically relevant improvement in approximately half of patients with chronic LBP. These findings provide an example of the importance of interdisciplinary collaboration in the treatment of chronic back pain patients.