Study design: Parallel-group randomized controlled trial.
Objective: Establish the short-term effectiveness of chiropractic therapy for spinal pain compared with a sham intervention and explore the predictors of chiropractic treatment satisfaction.
Summary of background data: Chiropractic treatment is widely used for spinal pain. However, a lack of sound evidence precludes conclusions about the effectiveness of chiropractic for spinal pain.
Methods: Participants were adults experiencing spinal pain, randomized to receive 2 treatments of chiropractic or sham therapy. Participants and outcome assessors were blinded to group allocation. Primary outcomes at 2 weeks were pain intensity (0-10 scale) and function (0-40 Functional Rating Index). Secondary outcomes were global change, minimum acceptable outcome, and treatment satisfaction. Treatment effects were estimated with linear mixed models for the primary outcomes. We used logistic regression to identify differences in the secondary outcomes and explore for predictors of treatment satisfaction.
Results: One hundred eighty three participants (chiropractic, n = 92; sham, n = 91) were recruited and included in the analyses. Participants receiving chiropractic therapy reported greater improvements in pain (mean difference, 95% confidence interval [CI] = 0.5 [0.1-0.9]), physical function (mean difference [95% CI] = 2.1 [0.3-4.0]), and were more likely to experience global improvement (48% vs. 24%, P = 0.01) and treatment satisfaction (78% vs. 56%, P < 0.01). There was no between-group difference in achieving a minimally acceptable outcome (34% sham vs. 29% chiropractic, P = 0.42). Awareness of treatment assignment and achieving minimally important improvement in pain intensity were associated with chiropractic treatment satisfaction.
Conclusion: Short-term chiropractic treatment was superior to sham; however, treatment effects were not clinically important. Awareness of treatment assignment and clinically important reductions in pain were associated with chiropractic treatment satisfaction.
Level of evidence: 2.