Patient expectations of benefit from common interventions for low back pain and effects on outcome: secondary analysis of a clinical trial of manual therapy interventions.

OBJECTIVES: The purpose of this secondary analysis was 1) to examine patient expectations related to a variety of common interventions for low back pain (LBP) and 2) to determine the influence that specific expectations about spinal manipulation might have had on self-report of disability.

METHODS: We collected patients' expectations about the benefit of specific interventions for low back pain. We also collected patients' general expectations about treatment and tested the relationships among the expectation of benefit from an intervention, receiving that intervention and disability-related outcomes.

RESULTS: Patients expected exercise and manual therapy interventions to provide more benefit than surgery and medication. There was a statistical association between expecting relief from thrust techniques and receiving thrust techniques, related to meeting the general expectation for treatment (chi-square: 15.5, P  =  0.008). This was not the case for patients who expected relief from thrust techniques but did not receive it (chi-square: 6.9, P  = 0.4). Logistic regression modeling was used to predict change in disability at treatment visit 5. When controlling for whether the general expectations for treatment were met, intervention assignment and the interaction between intervention assignment and expectations regarding thrust techniques, the parsimonious model only included intervention as the significant contributor to the model (P < 0.001). The adjusted odds ratio of success comparing thrust techniques to non-thrust in this study was 41.2 (11.0, 201.7).

DISCUSSION: The findings of this secondary analysis indicate that patients seeking intervention for LBP expect active interventions and manual therapy to significantly help improve their pain more than interventions like traction, rest, surgery, or medication. Additionally, in patients who meet the clinical prediction rule for good prognosis when managed with thrust techniques, treating with thrust techniques is more important than matching treatment to patient expectation.