Psychosocial Mechanisms of Cognitive-Behavioral-Based Physical Therapy Outcomes After Spine Surgery: Preliminary Findings From Mediation Analyses.

Abstract

Changing Behavior through Physical Therapy (CBPT), a cognitive-behavioral-based program, has been shown to improve outcomes after lumbar spine surgery in patients with a high psychosocial risk profile; however, little is known about potential mechanisms associated with CBPT treatment effects. The purpose of this study was to explore potential mediators underlying CBPT efficacy after spine surgery. In this secondary analysis, 86 participants were enrolled in a randomized trial comparing a postoperative CBPT (n=43) and education program (n=43). Participants completed validated questionnaires at 6weeks (baseline) and 3 and 6months following surgery for back pain (Brief Pain Inventory), disability (Oswestry Disability Index), physical health (12-Item Short-Form Health Survey), fear of movement (Tampa Scale for Kinesiophobia), pain catastrophizing (Pain Catastrophizing Scale), and pain self-efficacy (Pain Self-Efficacy Questionnaire). Parallel multiple mediation analyses using Statistical Package for the Social Sciences (SPSS) were conducted to examine whether 3- and 6-month changes in fear of movement, pain catastrophizing, and pain self-efficacy mediate treatment outcome effects at 6months. Six-month changes, but not 3-month changes, in fear of movement and pain self-efficacy mediated postoperative outcomes at 6months. Specifically, changes in fear of movement mediated the effects of CBPT treatment on disability (indirect effect=-2.0 [95% CI=-4.3 to 0.3]), whereas changes in pain self-efficacy mediated the effects of CBPT treatment on physical health (indirect effect=3.5 [95% CI=1.2 to 6.1]). This study advances evidence on potential mechanisms underlying cognitive-behavioral strategies. Future work with larger samples is needed to establish whether these factors are a definitive causal mechanism. Fear of movement and pain self-efficacy may be important mechanisms to consider when developing and testing psychologically informed physical therapy programs.