Pain self-efficacy, kinesiophobia and health-related quality of life mediate pain and disability improvements with goal setting and education in people with chronic low back pain: a mediation analysis of a randomised trial.

Abstract

How much do pain self-efficacy, kinesiophobia, stress and health-related quality of life mediate reductions in pain intensity and disability in people with chronic low back pain receiving a patient-led goal setting and pain science education intervention compared with general exercise advice? Secondary causal mediation analysis of a two-arm randomised controlled trial. Seventy-five people with chronic low back pain. Analyses were conducted in R software following a prospectively registered analysis plan. Four potential mediators were investigated independently using causal mediation analysis for pain intensity and disability. Mediator-outcome confounders were identified and controlled for, with sensitivity analyses used to assess robustness to confounding assumptions. All hypothesised mechanisms mediated the intervention effect on pain intensity (-1.8 points on a 0 to 10 scale): kinesiophobia (-1.0 indirect effect (IE), 95% CI -1.9 to -0.4, proportion mediated (PM), 58%), health-related quality of life (-0.7 IE, 95% CI -1.2 to -0.2, PM 36%), pain self-efficacy (-0.6 IE, 95% CI -1.2 to -0.2, PM 32%) and stress (-0.4 IE, 95% CI -0.9 to -0.0, PM 20%). Three hypothesised mechanisms mediated the intervention effect on disability (-10.6 points on a 0 to 100 scale): pain self-efficacy (-7.5 IE, 95% CI -13.0 to -3.1, PM 71%), health-related quality of life (-6.4 IE, 95% CI -11.3 to -2.3, PM 60%) and stress (-4.1 IE, 95% CI -8.6 to -0.9, PM 38%). Targeting pain self-efficacy, kinesiophobia and health-related quality of life may drive important reductions in pain intensity and disability following a goal setting and educational intervention for people with chronic low back pain. These mechanisms can be addressed through strategies that actively build confidence, reframe threat and support re-engagement in valued activities. Targeting self-efficacy can include grading individual goals and enabling individuals to experience improvements that build confidence. Kinesiophobia can be targeted by refining education to address unhelpful beliefs about activity and harm. Health-related quality of life can be targeted through focusing on meaningful, values-based goals that foster intrinsic motivation and help individuals reconnect with important roles and activities. OSF osf.io/w6kdr.