Aims: To investigate potential treatment effect modifiers of graded sensorimotor retraining on pain intensity and disability in the short and long-term.
Importance: Outcomes of low back pain management may be improved through targeted application of treatments to subgroups of patients who share traits, experiences or characteristics..
Methods: This study was a secondary analysis of the RESOLVE trial, a 2-group randomised sham-controlled, clinical trial. Participants with chronic non-specific low back pain were recruited from primary care settings and randomised (1:1) to either the intervention (graded sensorimotor retraining) or sham control groups. The study took place at a medical research institute in Sydney, Australia. Eight prespecified variables measured prior to randomisation were investigated for treatment effect modification using a linear regression model with statistical interaction tests. The primary outcomes were pain intensity (11- point numerical rating scale; range, 0 [no pain] to 10 [worst imaginable pain]) and disability (24- item Roland Morris Disability Questionnaire; scale range, 0-24 [higher scores indicate greater disability]) assessed at baseline, and 18 week and 52 weeks post randomisation.
RESULTS: 276 adults were randomised. Participants had a mean (SD) age of 46 (14.3) and 50% (n=138) were female. Pain self-efficacy, pain catastrophising, baseline pain intensity and psychoactive medication use did not have evidence for effect modification. Impaired back perception was identified as a potential treatment effect modifier of pain (Interaction effect 0.18, 95% CI 0.05 to 0.32; p=0.007) at 52 weeks post randomisation. Exploratory evidence (p<0.2) was identified for effect modification by kinesiophobia, baseline disability, back beliefs and back perception.
CONCLUSION: The benefits of graded sensorimotor retraining are likely to be similar for most people presenting for care with chronic non-specific low back pain.