RESUMO
The aim of this study was to explore on which variables a stress reduction program based on heart coherence can enhance the effects of a back school (BS) in patients with chronic non-specific low back pain and to explore possible moderators for treatment success. A retrospective explorative design was carried out with 170 patients with chronic non-specific low back pain. 89 Patients were admitted to BS and 81 patients were selected for BS and heart coherence training (BS-HCT). Six sessions of heart coherence were provided. At T0 (baseline) and T1 (discharge), the Numeric Rating Scale for pain (NRS pain), Roland Morris Disability Questionnaire (RMDQ), Pain Disability Index (PDI) and Rand-36 were administered in both groups. Both groups improved significantly on NRS pain, RMDQ, PDI and most of the Rand-36 subscales. On physical functioning, the BS-HCT group improved significantly more than the BS group (p = 0.02) but not after Bonferroni correction. Significant moderate correlations (r = 0.39 and r = 0.48) were found between the change of heart coherence and change of PDI and RMDQ respectively, but not with other variables. Baseline characteristics were not related to change on heart coherence. Providing HCT was more effective on physical functioning compared to a BS program. Change in heart coherence was related significantly to 2 out of 12 analyses. Placebo controlled and blinded studies are needed to confirm this. Characteristics of individuals who might benefit remain unknown. Evidence of this study is considered a level C, because of its pragmatic clinical character.